Home Preparation of (La + Nb)-co-doped TiO2 and its polyvinylidene difluoride composites with high dielectric constants
Article Open Access

Preparation of (La + Nb)-co-doped TiO2 and its polyvinylidene difluoride composites with high dielectric constants

  • Ke Su , Ruolin Han , Zheng Zhou , Guang-Xin Chen EMAIL logo and Qifang Li EMAIL logo
Published/Copyright: June 8, 2023
Download Article (PDF)
Become an author with De Gruyter Brill
Submit Manuscript Author Information
e-Polymers
From the journal e-Polymers Volume 23 Issue 1

Abstract

Numerous studies have shown that ceramic materials with high dielectric constants and low dielectric losses can be obtained using donor–acceptor-doped TiO2. In this study, (La + Nb)-co-doped TiO2 [(La0.5Nb0.5) x Ti1−x O2 x-LNTO] ceramic powders were prepared using the sol–gel method. XRD demonstrates that LNTO is a rutile phase, and the lattice parameters change after doping, while X-ray photoelectron spectroscopy explains the doping mechanism, with doping of TiO2 producing oxygen vacancies and Ti3+, which form defective dipoles with the dopant ions to increase the dielectric constant of the material. The dielectric properties were investigated by physically co-blending x-LNTO/polyvinylidene difluoride (PVDF) composites. Compared with the TiO2/PVDF composite, the dielectric properties of the x-LNTO/PVDF composite were more excellent. The dielectric constant of 5-LNTO/PVDF reached 36.96, which was higher than that of the TiO2/PVDF composite (19.49) at a filler addition of 60 wt% and a frequency of 1 kHz.

Keywords: co-doping; sol–gel method; ceramic powders; dielectric properties; composites

1 Introduction

The advent of the 5G era has imposed new requirements on various technical materials, and miniaturization, integration, and intelligence have become the major development directions (1,2,3). For materials with high dielectric constants, composites can combine the advantages of polymers and inorganic fillers, such as good mechanical properties and high dielectric constants, to a certain extent. In general, two major types of fillers are used to improve the dielectric properties of composite materials; the first type comprises conductive fillers, such as graphene (4) and carbon nanotubes (5,6). These fillers can considerably increase the dielectric constants of composite materials due to conductivity loss, increasing the dielectric loss of composite materials. The second type is composed of the most commonly used ceramic fillers, such as barium titanate (BaTiO3) (7,8,9), calcium copper titanate (CaCu3Ti4O12) (10,11,12,13), and lead zirconate titanate (PbZr1−x TiO3) (14,15).

A new material with a high dielectric constant, namely, co-doped TiO2, has been reported in recent years. Hu et al. (16) first discovered that using Nb and In co-doped TiO2 to construct a donor–acceptor co-doped system could produce TiO2 ceramic materials with high dielectric constants and low dielectric losses. Thereafter, researchers found that doping the rutile phase of TiO2 with donor ions B5+ (Nb5+, Ta5+, and Sb5+) and acceptor ions A3+ (In3+, Bi3+, Al3+, Sm3+, Ga3+, Sc3+, Yb3+, Y3+, Er3+, La3+, and Gd3+) could achieve extremely high dielectric constants, low dielectric losses, and good frequency/temperature stability (17,18,19,20,21,22,23,24,25,26,27,28,29) because B5+ has a small ionic radius, and thus, it can easily enter TiO2 cells and replace one Ti4+. Meanwhile, the additional electrons will be trapped by the neighboring Ti4+ to form Ti3+, and two A3+ ions will replace two Ti4+ ions and form oxygen vacancies V O ·· due to the charge balance. The final dopant ions will combine with oxygen vacancies V O ·· and Ti3+ to form a low-energy defect composite structure. A large number of defects will form electronic defect dipole clusters to achieve extremely high dielectric constants and frequency–temperature stability. Simultaneously, the defect dipole clusters can restrict the movement of free charges, and thus, reduce dielectric loss (16,19,30). A large number of studies have found that in addition to using trivalent lanthanide metal ions, monovalent metal ions A+ (Ag+ and Na+) (31,32,33), divalent metal ions A2+ (Ba2+, Ca2+, Mg2+, and Zn2+) (34,35,36,37,38), and tetravalent metal ions A4+ (Zr4+) (39), acceptor ions can also produce defect dipole effects with B5+ ions to achieve excellent dielectric properties. The combination of donor and acceptor ions for co-doped TiO2 systems with high dielectric constants was summarized and is shown in Figure 1.

Figure 1 The combination of donor and acceptor ions for co-doped TiO2 systems with high dielectric constants was realized in recent years.
Figure 1

The combination of donor and acceptor ions for co-doped TiO2 systems with high dielectric constants was realized in recent years.

After comparing several literature studies, the primary sources of trivalent acceptor ions were determined to be selected from nitrates; in addition, four choices of pentavalent donor ions, such as Nb sources, exist: Nb oxide (Nb2O5) (24,36,40), Nb ethanol (C10H25NbO5) (41), Nb metal (42), and Nb-containing salts (43,44). Nb2O5 is the preferred raw material for preparing co-doped TiO2 by using the high-temperature solid-phase method; it is inexpensive but the reaction requires a higher temperature and yields a material with a larger particle size. C10H25NbO5, Nb metal, and Nb salts can be used to prepare co-doped TiO2 via the sol–gel method, where C10H25NbO5 is the preferred raw material. However, the cost of this technique is high, making it unsuitable for mass preparation. In the case of metallic Nb, the conversion of Nb monomers into Nb5+ is a complex and dangerous process (42). By contrast, Nb-containing salts have their own free Nb5+, and thus, they are simple and relatively inexpensive to handle. In summary, the choice of the dopant ion source is of utmost importance in practical applications.

PVDF, polystyrene (PS), and epoxy resins are common substrates for the preparation of polymer-based dielectric composites, of which PVDF has a high dielectric constant and has received much attention. In the current study, the preparation process was further optimized by adjusting raw material composition by using the sol–gel method. La(NO3)3 and NbCl5 were used as doping raw materials to prepare (La, Nb)-co-doped TiO2 [(La0.5Nb0.5) x Ti1−x O2 x-LNTO, x = 1%, 2%, 3%, 5%] ceramic powders with different doping amounts. After that, x-LNTO/PVDF composite was prepared by compounding with polyvinylidene fluoride (PVDF), which has good dielectric properties.

2 Experimental section

2.1 Experimental materials

Titanium butoxide (C16H36O4Ti, Aladdin, 98% pure), lanthanum(iii) nitrate hexahydrate (La(NO3)3⋅6H2O, 99.99% pure), niobium(v) chloride (NbCl5, 3AChem 99.95% pure), citric acid (C6H8O7, Macklin, 99.5% pure), acetylacetone (C5H8O2, Aladdin, 99% pure), ethanol absolute (C2H6O, 99.7% pure), barium titanate (BaTiO3, Macklin, 99.9% pure, 200 nm), PVDF (98% pure), N,N-dimethylformamide (DMF, Aladdin, 98% pure), polyvinyl alcohol (PVA, 99.7% pure), and aluminum oxide (Al2O3, 99.7% pure) were used as starting materials.

2.2 Preparation of x-LNTO nanoparticles

The x-LNTO nanoparticles with different doping amounts were prepared by adjusting the contents of La and Nb elements (where the doping amount x = 1%, 2%, 3%, 5%). The preparation process is illustrated in Figure 2. First, 10.1 g of C16H36O4Ti (0.099 mol) was dissolved in 20 mL of C2H6O and 3 g of acetylacetone was added as a hydrolysis inhibitor to prevent hydrolysis after the addition of deionized water. Thereafter, 3–4 mL of deionized water was added and aged for 12 h. This solution was labeled Solution 1. Subsequently, 0.0405 g of NbCl5 (0.003 mol) and 0.064 g of La(NO3)3⋅6H2O (0.003 mol) were dissolved in 20 mL of C2H6O. Then, citric acid was added and stirred until it dissolved. This solution was labeled Solution 2.

Figure 2 Experimental process of preparing the x-LNTO ceramic powder.
Figure 2

Experimental process of preparing the x-LNTO ceramic powder.

Solutions 1 and 2 were mixed and allowed to react for 4 h. Thereafter, the solvent was dried in a high-temperature oven. The obtained powder was then ground, and the LNTO ceramic powder was produced via heat treatment at 1,100°C for 5 h by using a high-temperature tube furnace. When no doping elements are added, TiO2 ceramic particles can be obtained by following the aforementioned steps.

2.3 Preparation of x-LNTO/PVDF composites

Composites with different elemental doping and material fillings were prepared using a physical blending method. First 0.4 g of the x-LNTO ceramic powder was mixed with 5 mL of the DMF solution and sonicated for 1 h, after which 0.6 g of the PVDF powder was added, and the mixed solution was obtained by heating and stirring at 70°C. The mixed solution was then poured onto a glass plate and dried at 80°C to obtain x-LNTO/PVDF composite films with a filler content of 40 wt%. The same procedure was followed to prepare 50 and 60 wt% x-LNTO/PVDF composite films. TiO2/PVDF composites are also obtained by the same preparation process. The composite material is about 0.5–0.7 mm thick, about 5 cm long, and about 5 cm wide.

2.4 Characterization

The crystallographic analysis of the x-LNTO ceramic powder was performed by using X-ray diffraction (XRD; Instrument Ultima III) analysis, the morphological structure of the x-LNTO ceramic powder and x-LNTO ceramic powder/PVDF composite was analyzed by using scanning electron microscopy (SEM; HITACHI S-4700), and the elemental distribution of the x-LNTO ceramic powder was analyzed by using energy dispersive spectroscopy (EDS; Czech TESCAN MIRA LMS). X-ray photoelectron spectroscopy (XPS; Thermo Scientific K-Alpha, America) was used to analyze the valence states of the elements and the defect characterizations of the ceramic samples. Silver electrodes with a diameter of 5 mm were applied to both sides of the sample, after which the dielectric properties of the sample were tested using an impedance analyzer (Agilent 4294 A, America) in the frequency range of 40 Hz to 30 MHz.

3 Results and discussion

Figure 3a shows the XRD images of the TiO2 and 3-LNTO systems at 900°C. In accordance with the relevant literature, the phase transition temperature of TiO2 is within the range of 600–900°C (42). TiO2 was completely transformed into its rutile phase (PDF#88-1175) at 900°C, while 3-LNTO remained in its anatase phase (PDF#73-1764). Therefore, it can be inferred that the doping of TiO2 leads to an increase in the phase transition temperature, as verified in Figure 3b. Figure 3b shows that 3-LNTO is gradually transformed from the anatase phase to the rutile phase with an increase in the heat treatment temperature, and the complete rutile phase is achieved via treatment at 1,100°C for 5 h. The increase in the phase transition temperature after doping has been similarly reported in other literature studies, and the phase transition temperature increases with an increase in the doping amount (45) because the ionic radius of the doped element is larger than that of Ti4+ and the entry into the lattice is restricted. Moreover, doping hinders the rotation of the Ti–O bond during the phase transition of TiO2, leading to an increase in the phase transition temperature and the time required for the phase transition to reach equilibrium (46).

Figure 3 (a) XRD patterns of TiO2 and 3-LNTO systems at 900°C. (b) XRD patterns of 3-LNTO systems at different temperatures.
Figure 3

(a) XRD patterns of TiO2 and 3-LNTO systems at 900°C. (b) XRD patterns of 3-LNTO systems at different temperatures.

Figure 4 shows the XRD images of the x-LNTO ceramic powder obtained at 1,100°C. Figure 4a illustrates that each doping system is in the rutile phase (PDF#88-1175) and no other impurity phases are generated, indicating that doping will not change the original crystalline structure. In addition, peaks that belong to La4Ti9O24 appear near the (1 1 0) peak with an increase in the elemental doping content. This phenomenon is due to the doping concentration of La exceeding lattice solubility, resulting in the difficulty of replacing Ti4+ ions in the [TiO6] octahedron with several La3+ ions; therefore, the secondary phase appears in the system (30). The grain size of each doping system was calculated using the Scheele formula (Eq. 1), as shown in Table 1:

(1) D = K λ β cos θ

where D is the microcrystal size, K is a constant (= 0.89), λ is the wavelength of incident X-rays (0.15406 nm), β is the (110) peak width of the diffraction peak profile at half peak height (in rad), and θ is the Bragg diffraction angle. The crystal grain size of the system decreases with the increasing doping amount. This phenomenon is caused by doping.

Figure 4 XRD patterns of x-LNTO with (a) different doping amounts and (b) the magnification of its (1 1 0) peak obtained at 1,100°C.
Figure 4

XRD patterns of x-LNTO with (a) different doping amounts and (b) the magnification of its (1 1 0) peak obtained at 1,100°C.

Table 1

β, θ, and D values of different doping systems

Doping systems TiO2 1-LNTO 2-LNTO 3-LNTO 5-LNTO
β (rad) 0.002680 0.002879 0.002559 0.003575 0.003601
θ (°) 27.83 27.78 27.70 27.74 27.72
D (nm) 52.66 49.04 55.16 39.49 39.20

The (1 1 0) peak of x-LNTO was magnified (Figure 4b), and the (1 1 0) peak of the x-LNTO system was determined to have shifted to a lower angle. The corresponding diffraction angles are 27.83°, 27.78°, 27.7°, 27.74°, and 27.72° (x = 1%, 2%, 3%, and 5%), indicating that La and Nd successfully entered the TiO2 system. The shift in the (1 1 0) peak to a lower angle was due to a change in lattice parameters caused by doping; this change shifted the diffraction angle (22).

Figure 5 presents the SEM images of x-LNTO ceramic powders with different elemental doping amounts. Figure 5a–c clearly shows that the grain size decreases significantly with an increase in elemental doping. This finding is in accordance with the XRD analysis results. However, the higher sintering temperature prevents the grains from being dispersed as individual grains, causing some grains to sinter together. Figure 5d–f presents the EDS elemental analysis of the 1-LNTO ceramic powder. Evidently, La and Nb are uniformly distributed in the system, and the corresponding elemental density increases with an increase in elemental doping (Figure 5g and h). Therefore, La and Nb are proven to be successfully co-doped into the lattice.

Figure 5 SEM images of the x-LNTO ceramic powder with different doping contents: (a) 1%, (b) 3%, and (c) 5%. (d–f) Elemental mapping images for 1-LNTO ceramic materials. (h–g) Elemental mapping images for 3-LNTO ceramic materials.
Figure 5

SEM images of the x-LNTO ceramic powder with different doping contents: (a) 1%, (b) 3%, and (c) 5%. (d–f) Elemental mapping images for 1-LNTO ceramic materials. (h–g) Elemental mapping images for 3-LNTO ceramic materials.

Figure 6 shows the XPS spectra of 1-LNTO and 3-LNTO ceramic powders with regard to La 3d and Nb 3d. The typical characteristic double peak curves that belong to La3+ can be observed in both systems, as shown in Figure 6a and b (41). The electron binding energies that correspond to the La 3d3/2 and La 3d5/2 characteristic peaks of 1-LNTO are 851.68 and 835.08 eV, respectively. Similarly, the binding energies of the La 3d3/2 and La 3d5/2 characteristic peaks of 3-LNTO are 851.88 and 834.98 eV, respectively. Figure 6c and d shows the XPS spectra of Nb 3d; typical characteristic peaks that belong to Nb5+ are also observed (36). In addition, 207.08 and 209.88 eV are the binding energies of the characteristic peaks of Nb 3d3/2 and Nb 3d5/2 for 1-LNTO, respectively. The electron binding energies of Nb 3d3/2 and Nb 3d5/2 for 3-LNTO are 207.08 and 209.78 eV, respectively. The difference in the electron binding energies of Nb 3d3/2 and Nb 3d5/2 for the two systems are 2.8 and 2.8 eV, respectively, which are consistent with previously reported data (16). Moreover, no additional spikes are observed near 204.3 eV for both systems, confirming that only Nb5+ is present in the system; therefore, La and Nb can be proven to have entered the lattice successfully (47).

Figure 6 (a and b) XPS spectra of La 3d for the 1-LNTO and 3-LNTO systems. (c and d) XPS spectra of Nb 3d for the 1-LNTO and 3-LNTO systems.
Figure 6

(a and b) XPS spectra of La 3d for the 1-LNTO and 3-LNTO systems. (c and d) XPS spectra of Nb 3d for the 1-LNTO and 3-LNTO systems.

Figure 7 shows the XPS spectra of 1-LNTO and 3-LNTO ceramic powders with regard to O 1 s La 3d and Ti 2p. Figure 7a and b depicts that the main peaks of O 1 s of the 1-LNTO and 3-LNTO systems are located at 529.78 and 529.88 eV, respectively, which belong to the O lattice in the bulk Ti–O bond (16). The peak area of the corresponding XPS increases with an increase in the doping amount; thus, La and Nb can be proven to be successfully co-doped into the lattice (16,42). The peaks of 531.08 and 531.88 eV in the 1-LNTO system represent oxygen vacancies and surface hydroxyl groups, respectively; meanwhile, the peaks of 531.28 and 532.18 eV in the 3-LNTO system represent oxygen vacancies and surface hydroxyl groups, respectively (30). Correspondingly, the peak area of XPS that corresponds to oxygen vacancies will increase with an increase in the doping amount. This finding is consistent with the mechanism of action previously explored in the literature; the corresponding defect equation is as follows (42):

(2) La 2 O 3 → 2 TiO 2 2 La Ti ′ + V O ·· + 3 O O

Figure 7 (a and b) XPS spectra of O 1 s for the 1-LNTO and 3-LNTO systems. (c and d) XPS spectra of Ti 2p for the 1-LNTO and 3-LNTO systems.
Figure 7

(a and b) XPS spectra of O 1 s for the 1-LNTO and 3-LNTO systems. (c and d) XPS spectra of Ti 2p for the 1-LNTO and 3-LNTO systems.

Figure 7c and d shows the XPS spectral images of the system Ti 2p. The sharp peaks that correspond to 464.48 and 458.58 eV in the 1-LNTO system represent Ti 2p1/2 and Ti 2p3/2, respectively, while the characteristic peak that belongs to Ti3+ can be observed at 457.98 eV (22,26). Similarly, in the 3-LNTO system, the spikes at 464.38 and 458.78 eV represent Ti 2p1/2 and Ti 2p3/2, respectively; and a characteristic peak that belongs to Ti3+ can be observed at 457.78 eV. Ti3+ is generated when Nb5+ enters the lattice to replace Ti4+ and excess free electrons are trapped by the neighboring Ti4+ to form Ti3+ (37). The corresponding defect equation is as follows (16,36):

(3) Nb 2 O 5 + 2 TiO 2 → 2 Ti Ti ′ + 2 Nb Ti · + 8 O O + 1 2 O 2 ↑

(4) Ti 4 + + e → Ti 3 +

The XPS characterization of 1-LNTO and 3-LNTO can prove that La3+ and Nb5+ are successfully co-doped into the TiO2 lattice, and the effects produced by each doping element are explained and analyzed by fitting them into the analysis.

The dielectric constants of x-LNTO ceramic materials with different doping amounts are shown in Figure A1 (in Appendix), which have high dielectric constants. At 1 kHz, the dielectric constant of the LNTO ceramic material with 2% doping content reaches 2.76 × 104 with a dielectric loss of 0.4. Using it as a high dielectric filler compound with PVDF can effectively improve the dielectric properties of the composite.

Figure 8 presents the SEM images of 1-LNTO/PVDF composites with different filler contents. The images show that the 1-LNTO ceramic filler is uniformly dispersed in the PVDF matrix, and the filler density gradually increases as the filler content increases. The uniform distribution of the filler is beneficial to obtain composites with uniform property distribution, so it is very important to ensure a uniform distribution of the filler.

Figure 8 SEM images of 1-LNTO/PVDF composites with different filler contents: (a) 40 wt%, (b) 50 wt%, and (c) 60 wt%.
Figure 8

SEM images of 1-LNTO/PVDF composites with different filler contents: (a) 40 wt%, (b) 50 wt%, and (c) 60 wt%.

For composites prepared from two-phase composites, the effective dielectric constant (ε eff) of the composite can be expressed using Lichtenecker’s formula (Eq. 5):

(5) ε eff = nV 1 ε 1 + n V 1 ε 2

where ε 1 and ε 2 denote the dielectric constants of the two phases, V 1 and V 2 denote the volume fraction occupied by the two phases, and n is related to the experimental method. For the same polymer matrix, the higher the dielectric constant of the filler, the higher the dielectric constant of the obtained composite.

Figure 9 shows the images of the dielectric constant variation with frequency for the x-LNTO/PVDF composites with different doping amounts and filler contents. Overall, the dielectric constants of the composites are considerably improved by compounding x-LNTO with the PVDF matrix, and the dielectric constants of each x-LNTO/PVDF system are higher than those of the TiO2/PVDF system. The primary reason is that x-LNTO has a high dielectric constant; thus, doping in TiO2 with a medium dielectric constant causes La3+ and Nb5+ to replace Ti4+ and produce free electrons with oxygen vacancies V O ·· ; the dopant ions will then combine with V O ·· , and Ti3+ and Ti4+ will form a large number of low-energy defect composite structures, which, in turn, will form defective dipole clusters, considerably increasing the polarization of the filler (30).

Figure 9 Dielectric constants of the composites for each system at room temperature for different filler contents: (a) 40 wt%, (b) 50 wt%, and (c) 60 wt%. (d) The dielectric constant of each composite system at 1 kHz.
Figure 9

Dielectric constants of the composites for each system at room temperature for different filler contents: (a) 40 wt%, (b) 50 wt%, and (c) 60 wt%. (d) The dielectric constant of each composite system at 1 kHz.

Figure 9d presents the dielectric constants of the systems at 1 kHz. Evidently, the dielectric constants of the x-LNTO/PVDF systems are higher than those of the TiO2/PVDF systems, Similarly, the x-LNTO/PVDF composite still has good dielectric properties compared to the conventional BaTiO3/PVDF composite (Figure A2) because the x-LNTO ceramic material itself has a higher dielectric constant than TiO2 (with a dielectric constant of about 500) and BaTiO3 (with a dielectric constant of about 2,500). Therefore, as the doping level increases, the dielectric constant of LNTO does not cause an order of magnitude change.

Figure 10 shows the dielectric loss of the composites with frequency; all systems exhibit the same trend of dielectric loss with frequency. In the low-frequency region (<103 Hz), dielectric loss decreases. In the medium-frequency region (103–105 Hz), the dielectric loss is relatively flat. In the high-frequency region (>105 Hz), the dielectric loss continues to increase. The change in the dielectric loss can be attributed to the relationship between the internal polarization relaxation and the frequency of the material (48). Loss decreases at low frequencies because the dipole turning polarization can keep up with the electric field change (21). As frequency increases, the loss is kept relatively stable at mid-frequency because of electron aggregation at the interface due to interface polarization. When frequency continues to increase, the dipole turning polarization can no longer keep up with the electric field change; thus, material frequency continues to increase, and the relaxation peak at 107 Hz is generated by the relaxation process of PVDF (48).

Figure 10 Dielectric loss of the composites for each system at room temperature with different filler contents: (a) 40 wt%, (b) 50 wt%, and (c) 60 wt%. (d) The dielectric loss of each composite system at 1 kHz.
Figure 10

Dielectric loss of the composites for each system at room temperature with different filler contents: (a) 40 wt%, (b) 50 wt%, and (c) 60 wt%. (d) The dielectric loss of each composite system at 1 kHz.

As shown in Figure 10d, the difference in the dielectric loss between the systems at a certain filler content is insignificant, remaining low at low filler contents. At a filler content of 60 wt%, the dielectric loss is at a high level, although the dielectric constant is increased considerably primarily because of the high content of x-LNTO ceramic filler agglomerates in PVDF, causing the material dielectric loss to increase considerably.

4 Conclusions

In this study, (La + Nb)-co-doped TiO2 [(La0.5Nb0.5) x Ti1−x O2 x-LNTO] ceramic powders were prepared via the sol–gel method by using La(NO3)3 and NbCl5 as doping raw materials. x-LNTO was proven to belong to the rutile phase via XRD. After elemental doping, the (1 1 0) peak that belonged to the rutile phase shifted to a lower angle due to the introduction of doping elements La and Nb into the TiO2 lattice. The combined EDS and XPS analyses indicated that La3+ and Nb5+ were stably present in x-LNTO ceramics. By analyzing XPS spectra, the mechanism of action that produced a high dielectric constant was demonstrated. Doping led to the formation of Ti3+ with V O ·· , dopant ions combined with oxygen vacancies V O ·· and Ti3+ to form a low-energy defect complex structure, and a large number of defects led to the formation of electron-defect dipole clusters, achieving extremely high dielectric constants and low dielectric losses. Thereafter, x-LNTO/PVDF composites with different filler contents were prepared by physical blending. At a filler addition of 60 wt% and a frequency of 1 kHz, the dielectric constant of 5-LNTO/PVDF reached 36.96, which was higher than that of the TiO2/PVDF composites (19.49) and BaTiO3/PVDF composite (22.90). The difference in the dielectric constants of the fillers caused the 5-LNTO/PVDF composites to have higher dielectric constants.

fax: +86-10-64421693
fax: +86-10-64433585

Acknowledgments

The authors gratefully acknowledge the National Natural Science Foundation of China.

  1. Funding information: The financial support was provided by the National Natural Science Foundation of China (No. 51573010).

  2. Author contributions: Ke Su: Writing – original draft, Writing – review & editing, Methodology; Ruolin Han: Supervision; Zheng Zhou: Supervision; Guang-Xin Chen: Writing-Reviewing and Editing, Project administration; Qifang Li: Writing-Reviewing and Editing.

  3. Conflict of interest: The authors state no conflict of interest.

  4. Data availability statement: All data generated or analyzed during this study are included in this published article (and its supplementary information files).

Appendix

A1 Determination of the dielectric properties of x-LNTO ceramic materials

A certain amount of x-LNTO ceramic powder was mixed with 5 wt% PVA powder in water and then dried in an oven. After the PVA was completely dissolved, it was ground to obtain a homogeneous mixture in which the PVA acts as a binder. Afterward, a certain amount of ceramic powder was placed in a pressing mold and compacted with a pressure of 10 MPa, after which the x-LNTO and PVA sheet was released from the mold. The sheet was then placed in a crucible and deformed at 800°C in a high-temperature tube furnace in order to completely remove the PVA from the sheet and to prevent the CO2 generated by the decomposition of the PVA from reacting with the metal oxides at high temperatures. Afterwards, a thin layer of Al2O3 powder was placed inside the crucible to prevent the sheet from sticking to the crucible. x-LNTO ceramics were obtained by holding at 1,450°C for 6 h and cooling to room temperature, and the surface needs to be polished smooth in order to obtain more accurate dielectric properties.

A small amount of conductive silver paste was applied to both sides of the polished x-LNTO ceramic sheet in a 5 mm circle, after which it was placed in a blast oven for drying. This was followed by testing in the range of 40 Hz to 30 MHz using an impedance analyzer (Agilent 4294 A, America). Figure A1 shows the dielectric properties of the LNTO ceramic material.

Figure A1 Dielectric spectra of x-LNTO ceramics with different doping contents: (a) dielectric constant and (b) dielectric loss.
Figure A1

Dielectric spectra of x-LNTO ceramics with different doping contents: (a) dielectric constant and (b) dielectric loss.

A2 Preparation and dielectric properties testing of BaTiO3/PVDF composites

BaTiO3/PVDF composites with different material fillings were prepared using a physical blending method. First, 0.4 g of the BaTiO3 ceramic powder was mixed with 5 mL of the DMF solution and sonicated for 1 h. Afterward, 0.6 g of the PVDF powder was added, and the mixed solution was obtained by heating and stirring at 70°C. The mixed solution was then poured onto a glass plate and dried at 80°C to obtain BaTiO3/PVDF composite films with a filler content of 40 wt%. BaTiO3/PVDF composite films with 50 and 60 wt% were prepared by the same procedure.

The BaTiO3/PVDF composite was coated on both sides with a small amount of conductive silver paste in a 5 mm circle and then placed in a blast oven for drying. The impedance analyzer (Agilent 4294 A, America) was then used to perform tests in the range of 40 Hz to 30 MHz. The silver paste was applied to the surface to remove the effects of surface roughness and to reduce testing errors. Figure A2 shows the dielectric properties of the BaTiO3/PVDF composite.

Figure A2 Dielectric properties of BaTiO3/PVDF composites with different filler contents: (a) dielectric constant and (b) dielectric loss.
Figure A2

Dielectric properties of BaTiO3/PVDF composites with different filler contents: (a) dielectric constant and (b) dielectric loss.

References

(1) Zou K, Dan Y, Xu H, Zhang Q, Lu Y, Huang H, et al. Recent advances in lead-free dielectric materials for energy storage. Mater Res Bull. 2019;113:190–201.10.1016/j.materresbull.2019.02.002Search in Google Scholar

(2) Luo W, Yan S, Zhou J. Ceramic-based dielectric metamaterials. Interdiscip Mater. 2022;1(1):11–27.10.1002/idm2.12012Search in Google Scholar

(3) Palneedi H, Peddigari M, Hwang G-T, Jeong D-Y, Ryu J. High-performance dielectric ceramic films for energy storage capacitors: progress and outlook. Adv Funct Mater. 2018;28(42):1803665.10.1002/adfm.201803665Search in Google Scholar

(4) Lin B, Li Z-T, Yang Y, Li Y, Lin J-C, Zheng X-M, et al. Enhanced dielectric permittivity in surface-modified graphene/PVDF composites prepared by an electrospinning-hot pressing method. Compos Sci Technol. 2019;172:58–65.10.1016/j.compscitech.2019.01.003Search in Google Scholar

(5) Puértolas JA, García-García JF, Pascual FJ, González-Domínguez JM, Martínez MT, Ansón-Casaos A. Dielectric behavior and electrical conductivity of PVDF filled with functionalized single-walled carbon nanotubes. Compos Sci Technol. 2017;152:263–74.10.1016/j.compscitech.2017.09.016Search in Google Scholar

(6) Liu Y, Li L, Shi J, Han R, Wu P, Yue X, et al. High dielectric constant composites controlled by a strontium titanate barrier layer on carbon nanotubes towards embedded passive devices. Chem Eng J. 2019;373:642–50.10.1016/j.cej.2019.05.087Search in Google Scholar

(7) Shi K, Chai B, Zou H, Shen P, Sun B, Jiang P, et al. Interface induced performance enhancement in flexible BaTiO3/PVDF-TrFE based piezoelectric nanogenerators. Nano Energy. 2021;80:105515.10.1016/j.nanoen.2020.105515Search in Google Scholar

(8) Zhang Y, Zhang C, Feng Y, Zhang T, Chen Q, Chi Q, et al. Energy storage enhancement of P(VDF-TrFE-CFE)-based composites with double-shell structured BZCT nanofibers of parallel and orthogonal configurations. Nano Energy. 2019;66:104195.10.1016/j.nanoen.2019.104195Search in Google Scholar

(9) Yang K, Huang X, Zhu M, Xie L, Tanaka T, Jiang P. Combining RAFT polymerization and thiol-ene click reaction for core-shell structured polymer@BaTiO3 nanodielectrics with high dielectric constant, low dielectric loss, and high energy storage capability. ACS Appl Mater Interfaces. 2014;6(3):1812–22.10.1021/am4048267Search in Google Scholar PubMed

(10) Patel PK, Rani J, Yadav KL. Effective strategies for reduced dielectric loss in ceramic/polymer nanocomposite film. Ceram Int. 2021;47(7):10096–103.10.1016/j.ceramint.2020.12.157Search in Google Scholar

(11) Liu Y, Wu P, Kang P, Li L, Shi J, Zhou Z, et al. PDMS-based composites with stable dielectric properties at varied frequency via Sr-doped CaCu3Ti4O12 nanowires for flexible wideband antenna substrate. J Mater Sci Mater Electron. 2020;32(1):430–41.10.1007/s10854-020-04791-9Search in Google Scholar

(12) Du G, Wei F, Li W, Chen N. Co-doping effects of A-site Y3+ and B-site Al3+ on the microstructures and dielectric properties of CaCu3Ti4O12 ceramics. J Eur Ceram Soc. 2017;37(15):4653–9.10.1016/j.jeurceramsoc.2017.06.046Search in Google Scholar

(13) You X, Chen N, Du G. Constructing three-dimensionally interwoven structures for ceramic/polymer composites to exhibit colossal dielectric constant and high mechanical strength: CaCu3Ti4O12/epoxy as an example. Compos Part A: Appl Sci Manuf. 2018;105:214–22.10.1016/j.compositesa.2017.11.025Search in Google Scholar

(14) Zhang C, Sun H, Zhu Q. Preparation and property enhancement of poly(Vinylidene Fluoride) (PVDF)/lead zirconate titanate (PZT) composite piezoelectric films. J Electron Mater. 2021;50(11):6426–37.10.1007/s11664-021-09172-4Search in Google Scholar

(15) Du X, Zhou Z, Zhang Z, Yao L, Zhang Q, Yang H. Porous, multi-layered piezoelectric composites based on highly oriented PZT/PVDF electrospinning fibers for high-performance piezoelectric nanogenerators. J Adv Ceram. 2022;11(2):331–44.10.1007/s40145-021-0537-3Search in Google Scholar

(16) Hu W, Liu Y, Withers RL, Frankcombe TJ, Noren L, Snashall A, et al. Electron-pinned defect-dipoles for high-performance colossal permittivity materials. Nat Mater. 2013;12(9):821–6.10.1038/nmat3691Search in Google Scholar PubMed

(17) Zhao X-G, Chen L, Zhang X-Y, Liu P, Xu C-L, Hou Z-Y, et al. The abnormal multiple dielectric relaxation responses of Al3+ and Nb5+ co-doped rutile TiO2 ceramics. J Alloy Compd. 2021;860:157891.10.1016/j.jallcom.2020.157891Search in Google Scholar

(18) Wang L, Liu X, Bi X, Ma Z, Li J, Sun X. Origin of Colossal Dielectric Permittivity in (Nb + Ga) Co-Doped TiO2 Single Crystals. Cryst Growth Des. 2021;21(9):5283–91.10.1021/acs.cgd.1c00611Search in Google Scholar

(19) Fan J, Long Z, Zhou H, He G, Hu Z. Colossal dielectric behavior of (Ho, Ta) co-doped rutile TiO2 ceramics. J Mater Sci Mater Electron. 2021;32(11):14780–90.10.1007/s10854-021-06032-zSearch in Google Scholar

(20) Fan J, Long Z, Hu Z. Interface effects and defect clusters inducing thermal stability and giant dielectric response in (Ta+Y)-co-doped TiO2 ceramics. J Mater Sci Mater Electron. 2021;32(22):26232–40.10.1007/s10854-021-06825-2Search in Google Scholar

(21) Chen C, Xie Y, Chen P, Wang C. Mechanisms of the relaxations in (In + Nb) co-doped TiO2 ceramics. Ceram Int. 2021;47(18):26019–24.10.1016/j.ceramint.2021.06.007Search in Google Scholar

(22) Cao Z, Zhao J, Fan J, Li G, Zhang H. Colossal permittivity of (Gd + Nb) co-doped TiO2 ceramics induced by interface effects and defect cluster. Ceram Int. 2021;47(5):6711–9.10.1016/j.ceramint.2020.11.012Search in Google Scholar

(23) Wang XW, Zheng YP, Liang BK, Zhang G, Shi YC, Zhang BH, et al. Preparation and properties of La and Nb co-doped TiO2 colossal dielectric ceramic materials. J Mater Sci Mater Electron. 2020;31(18):16044–52.10.1007/s10854-020-04169-xSearch in Google Scholar

(24) Hu B, Sun K, Wang J, Xu J, Liu B, Zhang J, et al. High dielectric performance of (Nb5+, Lu3+) co-doped TiO2 ceramics in a broad temperature range. Mater Lett. 2020;271:127838–42.10.1016/j.matlet.2020.127838Search in Google Scholar

(25) Xu Z, Li L, Wang W, Lu T. Colossal permittivity and ultralow dielectric loss in (Nd0.5Ta0.5)xTi1-xO2 ceramics. Ceram Int. 2019;45(14):17318–24.10.1016/j.ceramint.2019.05.290Search in Google Scholar

(26) Fan J, Leng S, Cao Z, He W, Gao Y, Liu J, et al. Colossal permittivity of Sb and Ga co-doped rutile TiO2 ceramics. Ceram Int. 2019;45(1):1001–10.10.1016/j.ceramint.2018.09.279Search in Google Scholar

(27) Wang X, Zhang B, Xu L, Wang X, Hu Y, Shen G, et al. Dielectric properties of Y and Nb co-doped TiO2 ceramics. Sci Rep. 2017;7(1):8517.10.1038/s41598-017-09141-0Search in Google Scholar PubMed PubMed Central

(28) Ke S, Li T, Ye M, Lin P, Yuan W, Zeng X, et al. Origin of colossal dielectric response in (In + Nb) co-doped TiO2 rutile ceramics: a potential electrothermal material. Sci Rep. 2017;7(1):10144.10.1038/s41598-017-10562-0Search in Google Scholar PubMed PubMed Central

(29) Kawarasaki M, Tanabe K, Terasaki I, Fujii Y, Taniguchi H. Intrinsic Enhancement of Dielectric Permittivity in (Nb + In) co-doped TiO2 single crystals. Sci Rep. 2017;7(1):5351.10.1038/s41598-017-05651-zSearch in Google Scholar PubMed PubMed Central

(30) Zhao C, Li Z, Wu J. Role of trivalent acceptors and pentavalent donors in colossal permittivity of titanium dioxide ceramics. J Mater Chem C. 2019;7(14):4235–43.10.1039/C9TC00578ASearch in Google Scholar

(31) Zhu J, Wu D, Liang P, Zhou X, Peng Z, Chao X, et al. Ag+/W6+ co-doped TiO2 ceramic with colossal permittivity and low loss. J Alloy Compd. 2021;856:157350.10.1016/j.jallcom.2020.157350Search in Google Scholar

(32) Wang C, Li T, Xie Y, Wang J. Low-temperature Maxwell-Wagner relaxation in (Na + Nb) co‐doped rutile TiO2 colossal permittivity ceramics. J Am Ceram Soc. 2019;103(3):1839–45.10.1111/jace.16883Search in Google Scholar

(33) Liang P, Zhu J, Wu D, Peng H, Chao X, Yang Z. Good dielectric performance and broadband dielectric polarization in Ag, Nb co-doped TiO2. J Am Ceram Soc. 2021;104(6):2702–10.10.1111/jace.17660Search in Google Scholar

(34) Liu J, Xu J, Cui B, Yu Q, Zhong S, Zhang L, et al. Colossal permittivity characteristics and mechanism of (Sr, Ta) co-doped TiO2 ceramics. J Mater Sci Mater Electron. 2020;31(7):5205–13.10.1007/s10854-020-03080-9Search in Google Scholar

(35) Liu J, Wang L, Yin X, Yu Q, Xu D. Effect of ionic radius on colossal permittivity properties of (A, Ta) co-doped TiO2 (A= alkaline-earth ions) ceramics. Ceramics International. 2020;46(8):12059–66.10.1016/j.ceramint.2020.01.247Search in Google Scholar

(36) Yang C, Tse M-Y, Wei X, Hao J. Colossal permittivity of (Mg + Nb) co-doped TiO2 ceramics with low dielectric loss. J Mater Chem C. 2017;5(21):5170–5.10.1039/C7TC01020FSearch in Google Scholar

(37) Li Z, Luo X, Wu W, Wu J. Niobium and divalent-modified titanium dioxide ceramics: Colossal permittivity and composition design. J Am Ceram Soc. 2017;100(7):3004–12.10.1111/jace.14850Search in Google Scholar

(38) Dong W, Chen D, Hu W, Frankcombe TJ, Chen H, Zhou C, et al. Colossal permittivity behavior and its origin in rutile (Mg1/3Ta2/3)xTi1-xO2. Sci Rep. 2017;7(1):9950.10.1038/s41598-017-08992-xSearch in Google Scholar PubMed PubMed Central

(39) Yang C, Wei X, Hao J. Colossal permittivity in TiO2 co-doped by donor Nb and isovalent Zr. J Am Ceram Soc. 2018;101(1):307–15.10.1111/jace.15196Search in Google Scholar

(40) Zhu X, Yang L, Li J, Jin L, Wang L, Wei X, et al. The dielectric properties for (Nb,In,B) co-doped rutile TiO2 ceramics. Ceram Int. 2017;43(8):6403–9.10.1016/j.ceramint.2017.02.051Search in Google Scholar

(41) Hajizadeh-Oghaz M. Synthesis and characterization of Nb-La co-doped TiO2 nanoparticles by sol-gel process for dye-sensitized solar cells. Ceram Int. 2019;45(6):6994–7000.10.1016/j.ceramint.2018.12.200Search in Google Scholar

(42) Li J, Zeng Y, Fang Y, Chen N, Du G, Zhang A. Synthesis of (La + Nb) co-doped TiO2 rutile nanoparticles and dielectric properties of their derived ceramics composed of submicron-sized grains. Ceram Int. 2021;47(7):8859–67.10.1016/j.ceramint.2020.12.007Search in Google Scholar

(43) Liu R, Ren Y, Wang J, Wang Y, Jia J, Zhao G. Preparation of Nb-doped TiO2 films by sol-gel method and their dual-band electrochromic properties. Ceram Int. 2021;47(22):31834–42.10.1016/j.ceramint.2021.08.067Search in Google Scholar

(44) Ren Y, He H, Wang Y, Gong Y, Zhao G. Fabrication of F–Nb co-doped transparent conducting TiO2 films using the sol-gel method. Mater Sci Semicond Process. 2021;126:105675.10.1016/j.mssp.2021.105675Search in Google Scholar

(45) Wang J, Li X, Ren Y, Xia Z, Wang H, Jiang W, et al. The effects of additive on properties of Fe doped TiO2 nanoparticles by modified sol-gel method. J Alloy Compd. 2021;858:157726.10.1016/j.jallcom.2020.157726Search in Google Scholar

(46) Wang J, Wang Z, Zhao D, Liang Y, Wang H, Wang N, et al. Preparation, structural and photocatalytic activity of Sn/Fe co-doped TiO2 nanoparticles by sol-gel method. Ceram Int. 2022;48(6):8297–305.10.1016/j.ceramint.2021.12.034Search in Google Scholar

(47) Liu XD, Jiang EY, Li ZQ, Song QG. Electronic structure and optical properties of Nb-doped anatase TiO2. Appl Phys Lett. 2008;92(25):252104.10.1063/1.2949070Search in Google Scholar

(48) Dileep C, Muhammed Hunize CV, Murali KP. Colossal dielectric properties of (Zn0.5Ta0.5)0.02Ti0.98O2/PVDF composites. Bull Mater Sci. 2022;45(2):80.10.1007/s12034-022-02670-zSearch in Google Scholar
Received: 2023-03-23
Revised: 2023-05-11
Accepted: 2023-05-12
Published Online: 2023-06-08

© 2023 the author(s), published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

Articles in the same Issue

  1. Research Articles
  2. Chitosan nanocomposite film incorporating Nigella sativa oil, Azadirachta indica leaves’ extract, and silver nanoparticles
  3. Effect of Zr-doped CaCu3Ti3.95Zr0.05O12 ceramic on the microstructure, dielectric properties, and electric field distribution of the LDPE composites
  4. Effects of dry heating, acetylation, and acid pre-treatments on modification of potato starch with octenyl succinic anhydride (OSA)
  5. Loading conditions impact on the compression fatigue behavior of filled styrene butadiene rubber
  6. Characterization and compatibility of bio-based PA56/PET
  7. Study on the aging of three typical rubber materials under high- and low-temperature cyclic environment
  8. Numerical simulation and experimental research of electrospun polyacrylonitrile Taylor cone based on multiphysics coupling
  9. Experimental investigation of properties and aging behavior of pineapple and sisal leaf hybrid fiber-reinforced polymer composites
  10. Influence of temperature distribution on the foaming quality of foamed polypropylene composites
  11. Enzyme-catalyzed synthesis of 4-methylcatechol oligomer and preliminary evaluations as stabilizing agent in polypropylene
  12. Molecular dynamics simulation of the effect of the thermal and mechanical properties of addition liquid silicone rubber modified by carbon nanotubes with different radii
  13. Incorporation of poly(3-acrylamidopropyl trimethylammonium chloride-co-acrylic acid) branches for good sizing properties and easy desizing from sized cotton warps
  14. Effect of matrix composition on properties of polyamide 66/polyamide 6I-6T composites with high content of continuous glass fiber for optimizing surface performance
  15. Preparation and properties of epoxy-modified thermosetting phenolic fiber
  16. Thermal decomposition reaction kinetics and storage life prediction of polyacrylate pressure-sensitive adhesive
  17. Effect of different proportions of CNTs/Fe3O4 hybrid filler on the morphological, electrical and electromagnetic interference shielding properties of poly(lactic acid) nanocomposites
  18. Doping silver nanoparticles into reverse osmosis membranes for antibacterial properties
  19. Melt-blended PLA/curcumin-cross-linked polyurethane film for enhanced UV-shielding ability
  20. The affinity of bentonite and WO3 nanoparticles toward epoxy resin polymer for radiation shielding
  21. Prolonged action fertilizer encapsulated by CMC/humic acid
  22. Preparation and experimental estimation of radiation shielding properties of novel epoxy reinforced with Sb2O3 and PbO
  23. Fabrication of polylactic acid nanofibrous yarns for piezoelectric fabrics
  24. Copper phenyl phosphonate for epoxy resin and cyanate ester copolymer with improved flame retardancy and thermal properties
  25. Synergistic effect of thermal oxygen and UV aging on natural rubber
  26. Effect of zinc oxide suspension on the overall filler content of the PLA/ZnO composites and cPLA/ZnO composites
  27. The role of natural hybrid nanobentonite/nanocellulose in enhancing the water resistance properties of the biodegradable thermoplastic starch
  28. Performance optimization of geopolymer mortar blending in nano-SiO2 and PVA fiber based on set pair analysis
  29. Preparation of (La + Nb)-co-doped TiO2 and its polyvinylidene difluoride composites with high dielectric constants
  30. Effect of matrix composition on the performance of calcium carbonate filled poly(lactic acid)/poly(butylene adipate-co-terephthalate) composites
  31. Low-temperature self-healing polyurethane adhesives via dual synergetic crosslinking strategy
  32. Leucaena leucocephala oil-based poly malate-amide nanocomposite coating material for anticorrosive applications
  33. Preparation and properties of modified ammonium polyphosphate synergistic with tris(2-hydroxyethyl) isocynurate for flame-retardant LDPE
  34. Thermal response of double network hydrogels with varied composition
  35. The effect of coated calcium carbonate using stearic acid on the recovered carbon black masterbatch in low-density polyethylene composites
  36. Investigation of MXene-modified agar/polyurethane hydrogel elastomeric repair materials with tunable water absorption
  37. Damping performance analysis of carbon black/lead magnesium niobite/epoxy resin composites
  38. Molecular dynamics simulations of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) and TKX-50-based PBXs with four energetic binders
  39. Preparation and characterization of sisal fibre reinforced sodium alginate gum composites for non-structural engineering applications
  40. Study on by-products synthesis of powder coating polyester resin catalyzed by organotin
  41. Ab initio molecular dynamics of insulating paper: Mechanism of insulating paper cellobiose cracking at transient high temperature
  42. Effect of different tin neodecanoate and calcium–zinc heat stabilizers on the thermal stability of PVC
  43. High-strength polyvinyl alcohol-based hydrogel by vermiculite and lignocellulosic nanofibrils for electronic sensing
  44. Impacts of micro-size PbO on the gamma-ray shielding performance of polyepoxide resin
  45. Influence of the molecular structure of phenylamine antioxidants on anti-migration and anti-aging behavior of high-performance nitrile rubber composites
  46. Fiber-reinforced polyvinyl alcohol hydrogel via in situ fiber formation
  47. Preparation and performance of homogenous braids-reinforced poly (p-phenylene terephthamide) hollow fiber membranes
  48. Synthesis of cadmium(ii) ion-imprinted composite membrane with a pyridine functional monomer and characterization of its adsorption performance
  49. Impact of WO3 and BaO nanoparticles on the radiation shielding characteristics of polydimethylsiloxane composites
  50. Comprehensive study of the radiation shielding feature of polyester polymers impregnated with iron filings
  51. Preparation and characterization of polymeric cross-linked hydrogel patch for topical delivery of gentamicin
  52. Mechanical properties of rCB-pigment masterbatch in rLDPE: The effect of processing aids and water absorption test
  53. Pineapple fruit residue-based nanofibre composites: Preparation and characterizations
  54. Effect of natural Indocalamus leaf addition on the mechanical properties of epoxy and epoxy-carbon fiber composites
  55. Utilization of biosilica for energy-saving tire compounds: Enhancing performance and efficiency
  56. Effect of capillary arrays on the profile of multi-layer micro-capillary films
  57. A numerical study on thermal bonding with preheating technique for polypropylene microfluidic device
  58. Development of modified h-BN/UPE resin for insulation varnish applications
  59. High strength, anti-static, thermal conductive glass fiber/epoxy composites for medical devices: A strategy of modifying fibers with functionalized carbon nanotubes
  60. Effects of mechanical recycling on the properties of glass fiber–reinforced polyamide 66 composites in automotive components
  61. Bentonite/hydroxyethylcellulose as eco-dielectrics with potential utilization in energy storage
  62. Study on wall-slipping mechanism of nano-injection polymer under the constant temperature fields
  63. Synthesis of low-VOC unsaturated polyester coatings for electrical insulation
  64. Enhanced apoptotic activity of Pluronic F127 polymer-encapsulated chlorogenic acid nanoparticles through the PI3K/Akt/mTOR signaling pathway in liver cancer cells and in vivo toxicity studies in zebrafish
  65. Preparation and performance of silicone-modified 3D printing photosensitive materials
  66. A novel fabrication method of slippery lubricant-infused porous surface by thiol-ene click chemistry reaction for anti-fouling and anti-corrosion applications
  67. Development of polymeric IPN hydrogels by free radical polymerization technique for extended release of letrozole: Characterization and toxicity evaluation
  68. Tribological characterization of sponge gourd outer skin fiber-reinforced epoxy composite with Tamarindus indica seed filler addition using the Box–Behnken method
  69. Stereocomplex PLLA–PBAT copolymer and its composites with multi-walled carbon nanotubes for electrostatic dissipative application
  70. Enhancing the therapeutic efficacy of Krestin–chitosan nanocomplex for cancer medication via activation of the mitochondrial intrinsic pathway
  71. Variation in tungsten(vi) oxide particle size for enhancing the radiation shielding ability of silicone rubber composites
  72. Damage accumulation and failure mechanism of glass/epoxy composite laminates subjected to repeated low velocity impacts
  73. Gamma-ray shielding analysis using the experimental measurements for copper(ii) sulfate-doped polyepoxide resins
  74. Numerical simulation into influence of airflow channel quantities on melt-blowing airflow field in processing of polymer fiber
  75. Cellulose acetate oleate-reinforced poly(butylene adipate-co-terephthalate) composite materials
  76. Radiation shielding capability and exposure buildup factor of cerium(iv) oxide-reinforced polyester resins
  77. Recyclable polytriazole resins with high performance based on Diels-Alder dynamic covalent crosslinking
  78. Adsorption and recovery of Cr(vi) from wastewater by Chitosan–Urushiol composite nanofiber membrane
  79. Comprehensive performance evaluation based on electromagnetic shielding properties of the weft-knitted fabrics made by stainless steel/cotton blended yarn
  80. Review Articles
  81. Preparation and application of natural protein polymer-based Pickering emulsions
  82. Wood-derived high-performance cellulose structural materials
  83. Flammability properties of polymers and polymer composites combined with ionic liquids
  84. Polymer-based nanocarriers for biomedical and environmental applications
  85. A review on semi-crystalline polymer bead foams from stirring autoclave: Processing and properties
  86. Rapid Communication
  87. Preparation and characterization of magnetic microgels with linear thermosensitivity over a wide temperature range
  88. Special Issue: Biodegradable and bio-based polymers: Green approaches (Guest Editors: Kumaran Subramanian, A. Wilson Santhosh Kumar, and Venkatajothi Ramarao)
  89. Synthesis and characterization of proton-conducting membranes based on bacterial cellulose and human nail keratin
  90. Fatigue behaviour of Kevlar/carbon/basalt fibre-reinforced SiC nanofiller particulate hybrid epoxy composite
  91. Effect of citric acid on thermal, phase morphological, and mechanical properties of poly(l-lactide)-b-poly(ethylene glycol)-b-poly(l-lactide)/thermoplastic starch blends
  92. Dose-dependent cytotoxicity against lung cancer cells via green synthesized ZnFe2O4/cellulose nanocomposites
https://doi.org/10.1515/epoly-2023-0021
Keywords for this article
co-doping; sol–gel method; ceramic powders; dielectric properties; composites
Creative Commons
BY 4.0

Articles in the same Issue

  1. Research Articles
  2. Chitosan nanocomposite film incorporating Nigella sativa oil, Azadirachta indica leaves’ extract, and silver nanoparticles
  3. Effect of Zr-doped CaCu3Ti3.95Zr0.05O12 ceramic on the microstructure, dielectric properties, and electric field distribution of the LDPE composites
  4. Effects of dry heating, acetylation, and acid pre-treatments on modification of potato starch with octenyl succinic anhydride (OSA)
  5. Loading conditions impact on the compression fatigue behavior of filled styrene butadiene rubber
  6. Characterization and compatibility of bio-based PA56/PET
  7. Study on the aging of three typical rubber materials under high- and low-temperature cyclic environment
  8. Numerical simulation and experimental research of electrospun polyacrylonitrile Taylor cone based on multiphysics coupling
  9. Experimental investigation of properties and aging behavior of pineapple and sisal leaf hybrid fiber-reinforced polymer composites
  10. Influence of temperature distribution on the foaming quality of foamed polypropylene composites
  11. Enzyme-catalyzed synthesis of 4-methylcatechol oligomer and preliminary evaluations as stabilizing agent in polypropylene
  12. Molecular dynamics simulation of the effect of the thermal and mechanical properties of addition liquid silicone rubber modified by carbon nanotubes with different radii
  13. Incorporation of poly(3-acrylamidopropyl trimethylammonium chloride-co-acrylic acid) branches for good sizing properties and easy desizing from sized cotton warps
  14. Effect of matrix composition on properties of polyamide 66/polyamide 6I-6T composites with high content of continuous glass fiber for optimizing surface performance
  15. Preparation and properties of epoxy-modified thermosetting phenolic fiber
  16. Thermal decomposition reaction kinetics and storage life prediction of polyacrylate pressure-sensitive adhesive
  17. Effect of different proportions of CNTs/Fe3O4 hybrid filler on the morphological, electrical and electromagnetic interference shielding properties of poly(lactic acid) nanocomposites
  18. Doping silver nanoparticles into reverse osmosis membranes for antibacterial properties
  19. Melt-blended PLA/curcumin-cross-linked polyurethane film for enhanced UV-shielding ability
  20. The affinity of bentonite and WO3 nanoparticles toward epoxy resin polymer for radiation shielding
  21. Prolonged action fertilizer encapsulated by CMC/humic acid
  22. Preparation and experimental estimation of radiation shielding properties of novel epoxy reinforced with Sb2O3 and PbO
  23. Fabrication of polylactic acid nanofibrous yarns for piezoelectric fabrics
  24. Copper phenyl phosphonate for epoxy resin and cyanate ester copolymer with improved flame retardancy and thermal properties
  25. Synergistic effect of thermal oxygen and UV aging on natural rubber
  26. Effect of zinc oxide suspension on the overall filler content of the PLA/ZnO composites and cPLA/ZnO composites
  27. The role of natural hybrid nanobentonite/nanocellulose in enhancing the water resistance properties of the biodegradable thermoplastic starch
  28. Performance optimization of geopolymer mortar blending in nano-SiO2 and PVA fiber based on set pair analysis
  29. Preparation of (La + Nb)-co-doped TiO2 and its polyvinylidene difluoride composites with high dielectric constants
  30. Effect of matrix composition on the performance of calcium carbonate filled poly(lactic acid)/poly(butylene adipate-co-terephthalate) composites
  31. Low-temperature self-healing polyurethane adhesives via dual synergetic crosslinking strategy
  32. Leucaena leucocephala oil-based poly malate-amide nanocomposite coating material for anticorrosive applications
  33. Preparation and properties of modified ammonium polyphosphate synergistic with tris(2-hydroxyethyl) isocynurate for flame-retardant LDPE
  34. Thermal response of double network hydrogels with varied composition
  35. The effect of coated calcium carbonate using stearic acid on the recovered carbon black masterbatch in low-density polyethylene composites
  36. Investigation of MXene-modified agar/polyurethane hydrogel elastomeric repair materials with tunable water absorption
  37. Damping performance analysis of carbon black/lead magnesium niobite/epoxy resin composites
  38. Molecular dynamics simulations of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) and TKX-50-based PBXs with four energetic binders
  39. Preparation and characterization of sisal fibre reinforced sodium alginate gum composites for non-structural engineering applications
  40. Study on by-products synthesis of powder coating polyester resin catalyzed by organotin
  41. Ab initio molecular dynamics of insulating paper: Mechanism of insulating paper cellobiose cracking at transient high temperature
  42. Effect of different tin neodecanoate and calcium–zinc heat stabilizers on the thermal stability of PVC
  43. High-strength polyvinyl alcohol-based hydrogel by vermiculite and lignocellulosic nanofibrils for electronic sensing
  44. Impacts of micro-size PbO on the gamma-ray shielding performance of polyepoxide resin
  45. Influence of the molecular structure of phenylamine antioxidants on anti-migration and anti-aging behavior of high-performance nitrile rubber composites
  46. Fiber-reinforced polyvinyl alcohol hydrogel via in situ fiber formation
  47. Preparation and performance of homogenous braids-reinforced poly (p-phenylene terephthamide) hollow fiber membranes
  48. Synthesis of cadmium(ii) ion-imprinted composite membrane with a pyridine functional monomer and characterization of its adsorption performance
  49. Impact of WO3 and BaO nanoparticles on the radiation shielding characteristics of polydimethylsiloxane composites
  50. Comprehensive study of the radiation shielding feature of polyester polymers impregnated with iron filings
  51. Preparation and characterization of polymeric cross-linked hydrogel patch for topical delivery of gentamicin
  52. Mechanical properties of rCB-pigment masterbatch in rLDPE: The effect of processing aids and water absorption test
  53. Pineapple fruit residue-based nanofibre composites: Preparation and characterizations
  54. Effect of natural Indocalamus leaf addition on the mechanical properties of epoxy and epoxy-carbon fiber composites
  55. Utilization of biosilica for energy-saving tire compounds: Enhancing performance and efficiency
  56. Effect of capillary arrays on the profile of multi-layer micro-capillary films
  57. A numerical study on thermal bonding with preheating technique for polypropylene microfluidic device
  58. Development of modified h-BN/UPE resin for insulation varnish applications
  59. High strength, anti-static, thermal conductive glass fiber/epoxy composites for medical devices: A strategy of modifying fibers with functionalized carbon nanotubes
  60. Effects of mechanical recycling on the properties of glass fiber–reinforced polyamide 66 composites in automotive components
  61. Bentonite/hydroxyethylcellulose as eco-dielectrics with potential utilization in energy storage
  62. Study on wall-slipping mechanism of nano-injection polymer under the constant temperature fields
  63. Synthesis of low-VOC unsaturated polyester coatings for electrical insulation
  64. Enhanced apoptotic activity of Pluronic F127 polymer-encapsulated chlorogenic acid nanoparticles through the PI3K/Akt/mTOR signaling pathway in liver cancer cells and in vivo toxicity studies in zebrafish
  65. Preparation and performance of silicone-modified 3D printing photosensitive materials
  66. A novel fabrication method of slippery lubricant-infused porous surface by thiol-ene click chemistry reaction for anti-fouling and anti-corrosion applications
  67. Development of polymeric IPN hydrogels by free radical polymerization technique for extended release of letrozole: Characterization and toxicity evaluation
  68. Tribological characterization of sponge gourd outer skin fiber-reinforced epoxy composite with Tamarindus indica seed filler addition using the Box–Behnken method
  69. Stereocomplex PLLA–PBAT copolymer and its composites with multi-walled carbon nanotubes for electrostatic dissipative application
  70. Enhancing the therapeutic efficacy of Krestin–chitosan nanocomplex for cancer medication via activation of the mitochondrial intrinsic pathway
  71. Variation in tungsten(vi) oxide particle size for enhancing the radiation shielding ability of silicone rubber composites
  72. Damage accumulation and failure mechanism of glass/epoxy composite laminates subjected to repeated low velocity impacts
  73. Gamma-ray shielding analysis using the experimental measurements for copper(ii) sulfate-doped polyepoxide resins
  74. Numerical simulation into influence of airflow channel quantities on melt-blowing airflow field in processing of polymer fiber
  75. Cellulose acetate oleate-reinforced poly(butylene adipate-co-terephthalate) composite materials
  76. Radiation shielding capability and exposure buildup factor of cerium(iv) oxide-reinforced polyester resins
  77. Recyclable polytriazole resins with high performance based on Diels-Alder dynamic covalent crosslinking
  78. Adsorption and recovery of Cr(vi) from wastewater by Chitosan–Urushiol composite nanofiber membrane
  79. Comprehensive performance evaluation based on electromagnetic shielding properties of the weft-knitted fabrics made by stainless steel/cotton blended yarn
  80. Review Articles
  81. Preparation and application of natural protein polymer-based Pickering emulsions
  82. Wood-derived high-performance cellulose structural materials
  83. Flammability properties of polymers and polymer composites combined with ionic liquids
  84. Polymer-based nanocarriers for biomedical and environmental applications
  85. A review on semi-crystalline polymer bead foams from stirring autoclave: Processing and properties
  86. Rapid Communication
  87. Preparation and characterization of magnetic microgels with linear thermosensitivity over a wide temperature range
  88. Special Issue: Biodegradable and bio-based polymers: Green approaches (Guest Editors: Kumaran Subramanian, A. Wilson Santhosh Kumar, and Venkatajothi Ramarao)
  89. Synthesis and characterization of proton-conducting membranes based on bacterial cellulose and human nail keratin
  90. Fatigue behaviour of Kevlar/carbon/basalt fibre-reinforced SiC nanofiller particulate hybrid epoxy composite
  91. Effect of citric acid on thermal, phase morphological, and mechanical properties of poly(l-lactide)-b-poly(ethylene glycol)-b-poly(l-lactide)/thermoplastic starch blends
  92. Dose-dependent cytotoxicity against lung cancer cells via green synthesized ZnFe2O4/cellulose nanocomposites
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 10.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/epoly-2023-0021/html
Scroll to top button