Home Fractal analysis of pore structures in graphene oxide-carbon nanotube based cementitious pastes under different ultrasonication
Article Open Access

Fractal analysis of pore structures in graphene oxide-carbon nanotube based cementitious pastes under different ultrasonication

  • Yuan Gao , Hongwen Jing EMAIL logo and Zefu Zhou
Published/Copyright: July 12, 2019
Download Article (PDF)
Become an author with De Gruyter Brill
Submit Manuscript Author Information
Nanotechnology Reviews
From the journal Nanotechnology Reviews Volume 8 Issue 1

Abstract

Nano cement additive using a hybrid of graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs) combines the excellent affinity of GO and the superior mechanical properties of MWCNTs. Ultrasonication is the key process to disperse the GO/MWCNTs and further optimizes the pore structures of cement-based pastes. Fractal dimension can effectively and quantitatively characterize the pore structures of cementitious composites. The present study investigates the fractal dimensions of pore structures of GO/MWCNT-OPC pastes under power- and time-controlled ultrasonication based on the mercury intrusion porosimetry (MIP) tests data. The finding of this study shows that comparing to calculating the fractal dimension of the overall pore size range, assessing the variations of fractal dimension of individual pore size range is more effective in evaluating the pore characteristic. The fractal dimension of larger capillary pores D>104nmcan be use to describe the change of pore structure of GO/MWCNT-OPC pastes under ultrasonication treatment with sufficient accuracy as higher value of D>104nmindicates better pore characteristics. The fractal dimension change trend of mesopores is always opposite to that of bigger capillary pores. Modest increment in both power- and time-controlled ultrasonication seems to result in the increase of the fractal dimension of capillary pores and lead to better reinforcement effects. Prolongation of ultrasonication time slightly influences the pore structure of the specimens, while nano cement additives exposed to excess ultrasonication power fail to afford adequate reinforcing effect and finally cause the deterioration of the pore structures. The findings of this study can provide helpful information of GO/MWCNT-OPC pastes and ultrasonication treatment in the future.

Keywords: Graphene oxide; Multi-walled carbon nanotubes; Ultrasonication; Fractal dimension; Cement; Pore structures

1 Introduction

The pore characteristic is one of the key factors which significantly influence the mechanical properties [1, 2], permeability [3] as well as durability [4] of cementious material. Fractal theory has been widely used to characterize actual pore structure of porous materials since first introduced by Mandelbrot in 1979 [5]. After that researchers proposed various models and some well-known fractal patterns include Koch curve, Cantor bar, Sierpinski carpet and Mensor [6]. Although the pore structure of actual cement-based materials is much more complex than aforementioned fractal models, fractal dimension, in addition with other parameters such as intruded volume, average pore diameter and porosity, comprehensively considered the pore size distribution range and all of the above mentioned items is regard as a effective parameter for characterization of the microstructure [7].

Multiple methods are applied to characterize the pore structures of cement-based materials, including scanning electronic microscopy [8], mercury intrusion porosimetry (MIP) [9, 10], nuclear magnetic resonance [11] and small angle scattering of X-rays [12]. Among these techniques, MIP is the most common applied method due to its simple experimental procedure and the capability to capture various pore sizes ranging from nano- to milli-meter [13, 14].

Multi-walled carbon nanotubes (MWCNTs) have been utilized as nano-reinforcement to overcome the shortcomings of brittle cementitious materials [15, 16]. Graphene oxide (GO) as another outstanding cementitious composite additive, with several kinds of oxygen-containing functional groups, can both accelerate hydration reaction and densify the pore structure of cement pastes [1718, 19, 20]. Using a hybrid of GO and MWCNTs as nano-reinforcementmay be a better alternative. As this method can combine the affinity, well dispersibility of GO and the superior mechanical properties of MWCNTs. Zhang et al. [21] proposed that the interaction among GO sheets and MWCNTs involved π-π interactions, contributes to more stable disperse of MWCNTs in suspensions. Zhou et al. [22] reported that GO may act as the dispersant for MWCNTs to overcome agglomeration and showed the excellent reinforcing capabilities of their hybrid mixture in cementitious matrix. Gao et al. presented that mixing the multiple additives of GO/MWCNTs into cementitious composite may lead to an enhancing efficiency both in mechanical properties [15] and permeability [23].

Ultrasonication is frequently applied for the dispersion of GO and MWCNTs [24, 25]. The significance of picking a suitable ultrasonication energy that balances the separating effect and scissoring effect of the ultrasonication during the process has been widely emphasized in dispersion fabrication [26, 27]. However, there still lack of understandings on the influence of ultrasonication treatment on the GO/MWCNTs hybrid dispersion in cement-based materials, particularly the effect on the pore structure characteristics.

In this research, the fractal dimensions of pore structures in GO/MWCNT-OPC pastes under various ultrasonication treatments were systematically studied. A fractal model based on the Menger sponge pattern has been reviewed and the method of calculating fractal dimension of the cement-based pastes is then introduced. The pore size distribution data of the GO/MWCNT-OPC specimens was achieved through MIP tests. The results of this research reveal that it is more effective in characterizing the pore structures to assess the variations of fractal dimension of individual pore size range than overall section. The fractal dimension of larger capillary pores D>104nmis most accurate in characterizing the pore structure. The moderate increment of ultrasonication energy reinforces the pore structures of GO/MWCNT-OPC pastes,while excess ultrasonication power causes the deterioration of the pore structures. The findings of this research combine fractal analysis with ultrasonication treatment in the process of fabrication of GO/MWCNT-OPC pastes, and provide a new method to analyze ultrasonication effect from the fractal dimension of materials pore structures.

2 Fractal models

During recent years, fractal theory has provided a particularly quantitative framework to describe the cement-based materials physical phenomena over a range of temporal and spatial scales [6, 28]. The established model of Menger sponge algorithm has been used to simulate the intergranular pore structures of cementitious composites [29]. The process of the construction of typical Menger sponge model mainly consists of four stages as follows: first, a cube with unit length was subdivided into m3 smaller cubes of equal size. Then, n cubes are removed from the m3 cubes to leave (m3-n) cubes based on a specific rule. Furthermore, repeating the above two steps, the amounts of remained cubes are growing while the corresponding cube size is reduced. After repeating k times, the overall cube number Nk is (m3-n)k and the side length rk of the remained small cubes is 1/mk. The remained smaller cubes form the three-dimensional skeleton, with the volume Vk, and the removed cubes form the pore structures whose volume is marked as VP. According to the fractal theory, the relations between Nk and rk can be described as:

(1)Nk=rk−DM

Where DM represents the fractal dimension of the pore volume, is obtained as:

(2)DM=lgm3−n/lg  m

Then, multiplying the volume rk3of the small cube after iterations of k times on the both sides of the Eq. 1 to obtain

(3)Vk∝rk3−DM

According to a cube of unit length, the volume is linked to two items, i.e., pore volume VP, and matrix volume Vk, with the relation of VP + Vk = 1. Therefore, taking derivation on both sides of the Eq. 1 to obtain

(4)−dVpdr∝r2−DM

Then, taking the logarithm of the Eq. 4 yields the following equation:

(5)lg−dVpdr∝2−DMlg  r

During the MIP test, a fixed input pressure of P(r) is demanded to inject mercury into a certain pore size with the diameter of r. The relation between the pore size and cumulative pressure can be written using the Washburn method as [30]:

(6)Pr=−4γ cosθ/r×100%

Where P(r) is the cumulative mercury pressure, γ is the surface tension of mercury that equals to 358.2 dyn/cm, θ is the contact angle between solid surface and mercury that equals to 140∘ in this test.

Differentiating Eq. 6 with respect to r and P(r), Eq. 7 can be written as:

(7)Prdr+rdPr=0

Finally, combining of the Eqs. (5), (6) and (7), the fractal dimension DM can be obtained through the following equation:

(8)lgdVprdPr∝DM−4lgPr

Where, the fractal dimension DM of the specimens can be obtained by calculating the slope of the double logarithmic regression fitting relationship between P(r) and dVP(r)/dP(r).

3 Experimental process

3.1 Materials and instrumentation

In this study, graphene oxide-carbon nanotube based cementitious pastes were created using carbon nanomaterials as GO, MWCNTs (manufactured by Nanjing XFNANO Materials Tech Co, Nanjing City Jiangsu Province, China) and cement. Type P.O. 42.5 Portland cement, which satisfies the Chinese Standard GB175-2007 [31], was picked.

The chemical composition and physical properties of commercially manufactured GO, MWCNTs and OPC are exhibited in Table 1, 2, and 3, respectively. One commercial polycarboxylate-based surfactant (PC) was picked to enhance the dispersion degree of the GO/MWCNTs in suspensions [24].

Table 1

Chemical composition of OPC (%).

CaOSiO2Al2O3Fe2O3SO3MgOK2OTiO2OthersLoss
65.0120.695.714.182.520.610.610.310.323.26
Table 2

Physical properties of MWCNTs.

OuterInnerLengthPuritySpecificTap densityTrue density
diameterdiameterSurface Area
= 50 nm5–15 nm10–20 μm= 95%= 40 m2/g0.18 g/cm3~2.1 g/cm3
Table 3

Physical properties of GO.

DiameterThicknessSingle layer ratioPurity
500 nm–5 μm0.8–1.2 nm~ 99%= 99wt%

A horn ultrasonicator (VCX 500W) which can monitor the energy transferred to the suspensions in real time, with a cylindrical tip (end diameter: 13mm), was used for ultrasonication. The pore structures of the samples were characterized by mercury intrusion porosimeter (MIP) at ages of 28 days using AutoPore IV9500.

3.2 Preparation of specimens

A mixture containing five different components, as distilled water,GO,MWCNTs, PC and dry cement powder were first prepared. According to the author’s previous studies [15, 32], the concentration of MWCNTs and GO were defined as 0.04 wt.% and 0.02 wt.% relative to the overall weight of the suspensions, while the PC-to-suspensions ratio was chosen as 0.48 wt.% (8 times the weight of the carbon nanomaterials). After stirring the materials for 5 mins, the solution then was ultrasonicated to create the GO/MWCNT suspensions. The whole ultrasonication process was under a pulse mode with a short 3-second-pause during every 6-second period. A water-ice bath was placed surrounding the suspensions during the ultrasonication process to prevent overheating. Two series of GO/MWCNT suspensions were created with power-controlled and time-controlled ultrasonication, respectively. For the power-controlled, the power levels of ultrasonication were set as 55, 64, 73, 81, 87, 94, 109 and 118W and the time lasted for 15 min of each sample. For the time-controlled series, the ultrasonication time was fixed at 1, 3, 5, 10. 15, 20, 30, 40, and 60 min with the 94 W amplitude.

After the dispersing of GO/MWCNTs in the solution, the suspensions then were added into the cement powders based on the 0.4 water-to-cement ratio (w/c). The fresh mixtures were stirred at moderate and high speed until the completion of mixing, and then the fresh pastes were poured into 20 mm × 40 mm × 160 mm molds with enough vibrated in order to remove the entrapped air and ensure compaction, after that the specimens were covered with wet films to prevent moisture escaping. The specimens were demolded after 24 hours and conserved in the saturated lime water at 20 ± 5∘C for another 27 days before testing. Then the pore structures of GO/MWCNT-OPC harden pastes were characterized using MIP techniques and the fractal characteristics can be calculated. The detailed measurements of MIP tests are exhibited in Table 4 for GO/MWCNT-OPC pastes conducted by power- and time-controlled ultrasonication, respectively.

Table 4

Mercury intrusion porosimetry analysis of GO/MWCNT-OPC pastes.

SpecimensUltrasonicationMIP results
Power (W)Time (min)UE (KJ)Total intruded volume (ml/g)Porosity(%)
P-1–––0.17529.6
A-1551524.80.16726.9
A-26428.80.15726.1
A-37332.90.14224.5
A-48136.50.13423.2
A-58739.20.12722.2
A-69442.30.13623.8
A-710949.10.14825.1
A-811853.10.16226.8
B-19412.820.16427.8
B-238.460.14925.2
B-3514.10.15325.5
B-41028.20.14925.4
B-51542.30.14724.8
B-62056.40.13723.5
B-73084.60.13824.0
B-840112.80.13423.1
B-960169.20.13323.1

  1. (Note: UE represents the ultrasonication energy. P-1 represents the plain OPC pastes without any nano-additives.)

4 Results and discussion

4.1 Surface fractal characteristics in various pore-size ranges

Figure 1 presents the relation between lg dVprdPrand lg P(r) fitting using the pore size distribution of the Sample P-1. According to the Eq. (8), the surface fractal dimension

Figure 1 Logarithm plot of lg(dVP(r)/dP(r)) and lgP(r) in the entire pore size range (Sample P-1).
Figure 1

Logarithm plot of lg(dVP(r)/dP(r)) and lgP(r) in the entire pore size range (Sample P-1).

DM can be obtained through the linear regression analysis based on the slope of the fitting line and the DM is 3.297. According to the fractal theory [9], the fractal dimension ranges from 2 to 3 and DM = 2 means that pore structure is extremely flat while DM = 3 indicates that the pore characteristics become rough and irregular [33, 34]. In addition, a value of DM more than 3 implies that the model is beyond the three-dimensional space concept, and thus, it should not be considered as a physical from the geometric perspective [9]. As exhibited in Figure 1, the DM for the Sample P-1 is against the fundamental assumptions of fractal theory. In addition, as it can be seen, the coefficient of linear fitting of R2 is only up to 0.86, indicating that it is not reasonable to analyze the fractal dimension of the pore size range as a whole. Moreover, the pore characteristics of the cement-based materials include various pore sizes, ranging from nanoscale gel pores entrapped among the calcium silicate hydrate (C-S-H) hydration products to milli scale inside air voids [35], which influences the properties of the cementitious materials, such as the mechanical strength, permeability, and durability. The fractal dimension obtained from the entire pore size distribution range may present limitations of the materials [36].

Table 5

Mercury intrusion porosimetry analysis of GO/MWCNT-OPC pastes.

SpecimensUltrasonicationFractal dimensions
Power (W)Time (min)UE (KJ)D10−50nmD50−200nmD=104nm
P-1–––2.7062.7412.733
A-1551524.82.8742.5822.761
A-26428.82.7552.4772.87
A-37332.92.6942.6292.888
A-48136.52.6142.4622.843
A-58739.22.2092.3342.965
A-69442.32.6222.3532.839
A-710949.12.5772.7962.728
A-811853.12.8052.3182.673
B-19412.822.9142.3802.772
B-238.462.8742.5822.761
B-3514.12.8042.3202.792
B-41028.22.8142.7202.814
B-51542.32.7112.5302.834
B-62056.42.7292.7712.902
B-73084.62.6282.6832.887
B-840112.82.5452.9242.870
B-960169.22.2282.2362.954

To better describe the variations of the fractal characteristics of the test samples, the contribution and fractal dimension of five different types of pores as mesopores, middle capillary pores, bigger capillary pores with sizes <10, 10-50, 50-200,200-10000, and =10000 nm were considered respectively [37]. Figure 2 exhibits the relations between lg dVprdPrand lg P(r) for five regions of the test specimens, and the fractal dimensions are denoted as D<10nm,D10−50nm,D50−200nm,D200−104nmandD=104nm,respectively. However, the D<10 nm and D200−104nmare not recorded due to conflict with the fundamental assumptions of fractal theory. The detailed measurements are presented in Table 4 in three regions.

Figure 2 Logarithm plot of lg(dVP(r)/dP(r)) and lgP(r) in the different pore size range under power-controlled ultrasonication.
Figure 2

Logarithm plot of lg(dVP(r)/dP(r)) and lgP(r) in the different pore size range under power-controlled ultrasonication.

As exhibited in Figure 2, Figure 3 and Table 4, the mesopores in the ranges of 10-50 nm and 50-200 nm and bigger capillary pores with diameters larger than 104 nm are presented the fractal dimensions. The fractal characteristics of the bigger capillary pores, corresponding to the pores which are full of hydration products [19], are from 2.673 to 2.965. While the fractal dimensions of the mesopores in the range of 10-50 nm and 50-200 nm are 2.209-2.914 and 2.236-2.924, respectively.

Figure 3 Logarithm plot of lg(dVP(r)/dP(r)) and lgP(r) in the different pore size range under time-controlled ultrasonication.
Figure 3

Logarithm plot of lg(dVP(r)/dP(r)) and lgP(r) in the different pore size range under time-controlled ultrasonication.

4.2 Impact of power- and time-controlled

The correlations between the power-/time-controlled ultrasonication energy (UE) and the fractal dimensions of three pore size ranges D10−50 nm,D50−200 nm,  and D>104nmof the GO/MWCNT-OPC pastes are shown in Figure 4. As can be seen from Figure 4a, the D10−50 nm started at 2.874, the value declines constantly as the increase of the ultrasonication power and hits the minimum at 2.209 (Sample A-5), after that the figure rises again with the increase of ultrasonic energy. The value of D>104nmshows an opposite trend, whose figure grow continuously with the increase of the ultrasonication power and hit the peak at Sample A-5D>104nm=2.965too, after that the value shows a declined trend. However, the figure of the D50−200 nm shows a fluctuation state. According to the previous studies [15], in the power-controlled condition, with the increase of the ultrasonication energy, the degree of GO/MWCNTs materials dispersion enhanced constantly due to the ultrasonication separating forces while the length of the MWCNTs and the average diameter of the GO sheets were reduced respectively because of the ultrasonication scissoring forces. While the higher degree of dispersion and the well length distribution of the carbon nanomaterials contribute to a better pore structures of the cement-based pastes and higher fractal dimensions. Therefore, combined with the MIP test results, it implies that at the front of ultrasonication power growth, the ultrasonication separating forces play a major role, reinforcing the pore characteristics particularly in the bigger capillary pores. When the ultrasonication power continuously increases, the effects of the ultrasonication scissoring forces will exceed the separating forces and influence the pore structure of GO/MWCNT-OPC pastes. Moreover, the change trends of D10−50 nm and D>104nmare always the opposite which indicates that a certain amount of GO/MWCNTs materials reinforce the larger pores at first under better ultrasonication conditions.

Figure 4 Effect of ultrasonication energy on the fractal dimensions of GO/MWCNT-OPC pastes: (a) power-controlled, (b) time-controlled.
Figure 4

Effect of ultrasonication energy on the fractal dimensions of GO/MWCNT-OPC pastes: (a) power-controlled, (b) time-controlled.

Figure 4b indicates the effects of the time-controlled ultrasonication on the fractal dimensions at three ranges D10−50 nm,  D50−200 nm,  and  D>104nmof the GO/MWCNT-OPC pastes. With the increase of the ultrasonication time, the value of D10−50 nm exhibits a downward trend constantly, while that of D>104nmshows an upward trend with a plateau when the ultrasonication time exceeds 60 KJ. This phenomenon implies that at relatively low power, increasing ultrasonication time may only influence the mesopores, reducing its fractal dimensions, while little cause the change of the ultrasonication scissoring forces and has less impact on macro pores. The findings are in good agreement with the previous studies that prolongation the ultrasonication time little affect the dispersion of GO/MWCNTs in the suspensions and the mechanical properties of its cement-based pastes. However, the further increase of the ultrasonication power may cause the deterioration of these items.

5 Conclusions

This study investigates the fractal dimensions of pore structures of GO/MWCNT-OPC pastes in power- and time-controlled ultrasonication. The main findings are as follow:

  1. The fractal dimension obtained from the overall pore size ranges presents limitations of the materials. To allow for better fractal analysis and evaluate the pore characteristics of specimens, it is more feasible to assess the variations of fractal dimension of the individual pore size range of the GO/MWCNT-OPC pastes, the contribution of five different types of pores as mesopores, middle capillary pores, bigger capillary pores with the sizes <10, 10-50, 50-200,200-104, and =104 nm.

  2. The correlation between the ultrasonication energy and mechanical properties, permeability, and durability of the GO/MWCNT-OPC pastes owns the similar change trend with the relationship between that and the fractal dimension of the bigger capillary pores D>104nm.Moreover, the change trends of D10−50 nm and D>104nmwith ultrasonication energy are always the opposite, indicating that a certain amount of GO/MWCNTs materials could reinforce the larger pores at first under better ultrasonication treatment.

  3. The moderate increment of ultrasonication power and time may both enhance the pore structures of the GO/MWCNT-OPC pastes by increasing the factual dimension of bigger capillary pores D>104nm.After that, excess ultrasonication energy in power-controlled treatment would cause the deterioration of the pore structures, decreasing the capillary pores factual dimension, while prolonging the ultrasonication time has little influence on the pore structures.

It is expected that the results of this study could provide helpful information in the fields of analyzing and predicting the mechanical and transport properties of the carbon nanomaterials additive cementitious composites under different ultrasonication treatments.

Acknowledgement

This study was supported by the National Natural Science Foundation of China, China (No. 51734009) and Postgraduate Education Reform Project of Jiangsu Province, China.

  1. Conflict of Interest

    Conflict of Interests: The authors declare no conflict of interest.

References

[1] T. Matusinović, J. Šipušić, N. Vrbos, Porosity-strength relation in calcium aluminate cement pastes, Cem. Concr. Res. (2003). doi:10.1016/S0008-8846(03)00201-1.10.1016/S0008-8846(03)00201-1Search in Google Scholar

[2] A.U. Ozturk, B. Baradan, A comparison study of porosity and compressive strength mathematical models with image analysis, Comput. Mater. Sci. (2008). 10.1016/j.commatsci.2008.02.011Search in Google Scholar

[3] C. Atzeni, G. Pia, U. Sanna, A geometrical fractal model for the porosity and permeability of hydraulic cement pastes, Constr. Build. Mater. (2010). 10.1016/j.conbuildmat.2010.04.020Search in Google Scholar

[4] R. Liu, H. Xiao, H. Li, L. Sun, Z. Pi, G.Q. Waqar, T. Du, L. Yu, Effects of nano-SiO2 on the permeability-related properties of cement-based composites with different water/cement ratios, J. Mater. Sci. (2018). doi:10.1007/s10853-017-1906-8.10.1007/s10853-017-1906-8Search in Google Scholar

[5] C.W. Kilmister, B.B. Mandelbrot, Fractals: Form, Chance and Dimension, Math. Gaz. (2007). doi:10.2307/3617679.10.2307/3617679Search in Google Scholar

[6] J.W. Cannon, B.B. Mandelbrot, The Fractal Geometry of Nature., Am. Math. Mon. (1984). doi:10.2307/2323761.10.2307/2323761Search in Google Scholar

[7] Q. Zeng, K. Li, T. Fen-Chong, P. Dangla, Surface fractal analysis of pore structure of high-volume fly-ash cement pastes, Appl. Surf. Sci. (2010). doi:10.1016/j.apsusc.2010.07.061.10.1016/j.apsusc.2010.07.061Search in Google Scholar

[8] Y. Wang, S. Diamond, A fractal study of the fracture surfaces of cement pastes and mortars using a stereoscopic SEM method, Cem. Concr. Res. (2001). doi:10.1016/S0008-8846(01)00591-9.10.1016/S0008-8846(01)00591-9Search in Google Scholar

[9] B. Zhang, S. Li, Determination of the Surface Fractal Dimension for Porous Media by Mercury Porosimetry, Ind. Eng. Chem. Res. (1995). doi:10.1021/ie00043a044.10.1021/ie00043a044Search in Google Scholar

[10] B. Zhang, W. Liu, X. Liu, Scale-dependent nature of the surface fractal dimension for bi- and multi-disperse porous solids by mercury porosimetry, Appl. Surf. Sci. (2006). doi:10.1016/j.apsusc.2006.02.009.10.1016/j.apsusc.2006.02.009Search in Google Scholar

[11] R. Blinc, G. Lahajnar, S. Umer, M.M. Pintar, NMR study of the time evolution of the fractal geometry of cement gels, Phys. Rev. B. (1988). doi:10.1103/PhysRevB.38.2873.10.1103/PhysRevB.38.2873Search in Google Scholar

[12] D. Pearson, A.J. Allen, A study of ultrafine porosity in hydrated cements using small angle neutron scattering, J. Mater. Sci. (1985). doi:10.1007/BF00555924.10.1007/BF00555924Search in Google Scholar

[13] H.M. Jennings, J.J. Thomas, J.S. Gevrenov, G. Constantinides, F.J. Ulm, A multi-technique investigation of the nanoporosity of cement paste, Cem. Concr. Res. (2007). doi:10.1016/j.cemconres.2006.03.021.10.1016/j.cemconres.2006.03.021Search in Google Scholar

[14] H.M. Jennings, J.W. Bullard, J.J. Thomas, J.E. Andrade, J.J. Chen, G.W. Scherer, Characterization and Modeling of Pores and Surfaces in Cement Paste: Correlations to Processing and Properties, J. Adv. Concr. Technol. (2008). doi:10.3151/jact.6.5.10.3151/jact.6.5Search in Google Scholar

[15] Y. Gao, H.W. Jing, S.J. Chen, M.R. Du, W.Q. Chen, W.H. Duan, Influence of ultrasonication on the dispersion and enhancing effect of graphene oxide–carbon nanotube hybrid nanoreinforcement in cementitious composite, Compos. Part B Eng. (2019). 10.1016/j.compositesb.2018.11.066Search in Google Scholar

[16] F. Collins, J. Lambert, W.H. Duan, The influences of admixtures on the dispersion, workability, and strength of carbon nanotube-OPC paste mixtures, Cem. Concr. Compos. (2012). doi:10.1016/j.cemconcomp.2011.09.013.10.1016/j.cemconcomp.2011.09.013Search in Google Scholar

[17] A.K. Geim, K.S. Novoselov, The rise of graphene, Nat. Mater. (2007). doi:10.1038/nmat1849.10.1038/nmat1849Search in Google Scholar

[18] Z. Dai, W. Chen, G. Lv, W. Hu, D. Li, S. Chen, Synthesis and applications of graphene quantum dots: a review, Nanotechnol. Rev. 7 (2018) 157–185. doi:10.1515/ntrev-2017-0199.10.1515/ntrev-2017-0199Search in Google Scholar

[19] D. Hou, Z. Lu, X. Li, H.Ma, Z. Li, Reactive molecular dynamics and experimental study of graphene-cement composites: Structure, dynamics and reinforcement mechanisms, Carbon N. Y. (2017). doi:10.1016/j.carbon.2017.01.013.10.1016/j.carbon.2017.01.013Search in Google Scholar

[20] K. Gong, S.M. Asce, Z. Pan, A.H. Korayem, D. Ph, L. Qiu, D. Li, F. Collins, C.M. Wang, W.H. Duan, a M. Asce, Reinforcing Effects of Graphene Oxide on Portland Cement Paste, J. Mater. Civ. Eng. (2014). doi:10.1061/(ASCE)MT.1943-5533.0001125.10.1061/(ASCE)MT.1943-5533.0001125Search in Google Scholar

[21] C. Zhang, L. Ren, X. Wang, T. Liu, Graphene oxide-assisted dispersion of pristine multiwalled carbon nanotubes in aqueous media, J. Phys. Chem. C. (2010). doi:10.1021/jp103745g.10.1021/jp103745gSearch in Google Scholar

[22] C. Zhou, F. Li, J. Hu, M. Ren, J. Wei, Q. Yu, Enhanced mechanical properties of cement paste by hybrid graphene oxide/carbon nanotubes, Constr. Build. Mater. (2017). 10.1016/j.conbuildmat.2016.12.147Search in Google Scholar

[23] Y. Gao, H.W. Jing, Z.F. Zhou, W.Q. Chen, M.R. Du, Y. Du, Influence of graphene oxide-carbon nanotube hybrid nano-reinforcement on the transport properties of cementitious composites with different water-to-cement ratios, Constr. Build. Mater.Search in Google Scholar

[24] B. Zou, S.J. Chen, A.H. Korayem, F. Collins, C.M.Wang,W.H. Duan, Effect of ultrasonication energy on engineering properties of carbon nanotube reinforced cement pastes, Carbon N. Y. (2015). doi:10.1016/j.carbon.2014.12.094.10.1016/j.carbon.2014.12.094Search in Google Scholar

[25] S.J. Chen, B. Zou, F. Collins, X.L. Zhao, M. Majumber, W.H. Duan, Predicting the influence of ultrasonication energy on the reinforcing efflciency of carbon nanotubes, Carbon N. Y. 77 (2014) 1–10. doi:10.1016/j.carbon.2014.04.023.10.1016/j.carbon.2014.04.023Search in Google Scholar

[26] A. Lucas, C. Zakri, M. Maugey, M. Pasquali, P. Van Der Schoot, P. Poulin, Kinetics of nanotube and microfiber scission under sonication, J. Phys. Chem. C. (2009). doi:10.1021/jp906296y.10.1021/jp906296ySearch in Google Scholar

[27] M.S. Strano, V.C. Moore, M.K. Miller, M.J. Allen, E.H. Haroz, C. Kittrell, R.H. Hauge, R.E. Smalley, The Role of Surfactant Adsorption during Ultrasonication in the Dispersion of Single-Walled Carbon Nanotubes, J. Nanosci. Nanotechnol. 3 (2003) 81–86. doi:10.1166/jnn.2003.194.10.1166/jnn.2003.194Search in Google Scholar

[28] E. Perfect, B.D. Kay, Applications of fractals in soil and tillage research: a review, Soil Tillage Res. (1995). doi:10.1016/0167-1987(96)81397-3.10.1016/0167-1987(96)81397-3Search in Google Scholar

[29] D. Giménez, E. Perfect, W.J. Rawls, Y. Pachepsky, Fractal models for predicting soil hydraulic properties: a review, Eng. Geol. (2002). doi:10.1016/s0013-7952(97)00038-0.10.1016/s0013-7952(97)00038-0Search in Google Scholar

[30] L.R. Fisher, P.D. Lark, An experimental study of the washburn equation for liquid flow in very fine capillaries, J. Colloid Interface Sci. (1979). doi:10.1016/0021-9797(79)90138-3.10.1016/0021-9797(79)90138-3Search in Google Scholar

[31] C.S. GB175, Common portland cement, Beijing, PR China. (2007).Search in Google Scholar

[32] Y. Gao, H. Jing, M. Du, W. Chen, Dispersion of Multi-Walled Carbon Nanotubes Stabilized by Humic Acid in Sustainable Cement Composites, (2018). doi:10.3390/nano8100858.10.3390/nano8100858Search in Google Scholar PubMed PubMed Central

[33] M.M. Mahamud, J.M. Menéndez, P.E. Sarquís, CO2 activation of chars: Effect of burn-off on texture and fractal properties, Fuel Process. Technol. (2014). doi:10.1016/j.fuproc.2013.10.009.10.1016/j.fuproc.2013.10.009Search in Google Scholar

[34] G.J. Lee, S. Il Pyun, The effect of pore structures on fractal characteristics of meso/macroporous carbons synthesised using silica template [8], Carbon N. Y. (2005). doi:10.1016/j.carbon.2005.02.009.10.1016/j.carbon.2005.02.009Search in Google Scholar

[35] P.K. Mehta, P.J.M. Monteiro, Concreto: Microestrutura, Propriedades e Materiais., 2014. doi:10.1036/0071462899.10.1036/0071462899Search in Google Scholar

[36] J. Kim, Y.C. Choi, S. Choi, Fractal Characteristics of Pore Structures in GGBFS-based Cement Pastes, Appl. Surf. Sci. (2018). doi:10.1016/j.apsusc.2017.09.165.10.1016/j.apsusc.2017.09.165Search in Google Scholar

[37] Y. Zhao, Z. Feng, Y. Zhao, Z. Wan, Experimental investigation on thermal cracking, permeability under HTHP and application for geothermal mining of HDR, Energy. (2017). doi:10.1016/j.energy.2017.05.093.10.1016/j.energy.2017.05.093Search in Google Scholar

Received: 2019-03-18
Accepted: 2019-04-11
Published Online: 2019-07-12

© 2019 Y. Gao et al., published by De Gruyter

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

Articles in the same Issue

  1. Research Articles
  2. Investigation of rare earth upconversion fluorescent nanoparticles in biomedical field
  3. Carbon Nanotubes Coated Paper as Current Collectors for Secondary Li-ion Batteries
  4. Insight into the working wavelength of hotspot effects generated by popular nanostructures
  5. Novel Lead-free biocompatible piezoelectric Hydroxyapatite (HA) – BCZT (Ba0.85Ca0.15Zr0.1Ti0.9O3) nanocrystal composites for bone regeneration
  6. Effect of defects on the motion of carbon nanotube thermal actuator
  7. Dynamic mechanical behavior of nano-ZnO reinforced dental composite
  8. Fabrication of Ag Np-coated wetlace nonwoven fabric based on amino-terminated hyperbranched polymer
  9. Fractal analysis of pore structures in graphene oxide-carbon nanotube based cementitious pastes under different ultrasonication
  10. Effect of PVA fiber on durability of cementitious composite containing nano-SiO2
  11. Cr effects on the electrical contact properties of the Al2O3-Cu/15W composites
  12. Experimental evaluation of self-expandable metallic tracheobronchial stents
  13. Experimental study on the existence of nano-scale pores and the evolution of organic matter in organic-rich shale
  14. Mechanical characterizations of braided composite stents made of helical polyethylene terephthalate strips and NiTi wires
  15. Mechanical properties of boron nitride sheet with randomly distributed vacancy defects
  16. Fabrication, mechanical properties and failure mechanism of random and aligned nanofiber membrane with different parameters
  17. Micro- structure and rheological properties of graphene oxide rubber asphalt
  18. First-principles calculations of mechanical and thermodynamic properties of tungsten-based alloy
  19. Adsorption performance of hydrophobic/hydrophilic silica aerogel for low concentration organic pollutant in aqueous solution
  20. Preparation of spherical aminopropyl-functionalized MCM-41 and its application in removal of Pb(II) ion from aqueous solution
  21. Electrical conductivity anisotropy of copper matrix composites reinforced with SiC whiskers
  22. Miniature on-fiber extrinsic Fabry-Perot interferometric vibration sensors based on micro-cantilever beam
  23. Electric-field assisted growth and mechanical bactericidal performance of ZnO nanoarrays with gradient morphologies
  24. Flexural behavior and mechanical model of aluminum alloy mortise-and-tenon T-joints for electric vehicle
  25. Synthesis of nano zirconium oxide and its application in dentistry
  26. Surface modification of nano-sized carbon black for reinforcement of rubber
  27. Temperature-dependent negative Poisson’s ratio of monolayer graphene: Prediction from molecular dynamics simulations
  28. Finite element nonlinear transient modelling of carbon nanotubes reinforced fiber/polymer composite spherical shells with a cutout
  29. Preparation of low-permittivity K2O–B2O3–SiO2–Al2O3 composites without the addition of glass
  30. Large amplitude vibration of doubly curved FG-GRC laminated panels in thermal environments
  31. Enhanced flexural properties of aramid fiber/epoxy composites by graphene oxide
  32. Correlation between electrochemical performance degradation and catalyst structural parameters on polymer electrolyte membrane fuel cell
  33. Materials characterization of advanced fillers for composites engineering applications
  34. Humic acid assisted stabilization of dispersed single-walled carbon nanotubes in cementitious composites
  35. Test on axial compression performance of nano-silica concrete-filled angle steel reinforced GFRP tubular column
  36. Multi-scale modeling of the lamellar unit of arterial media
  37. The multiscale enhancement of mechanical properties of 3D MWK composites via poly(oxypropylene) diamines and GO nanoparticles
  38. Mechanical properties of circular nano-silica concrete filled stainless steel tube stub columns after being exposed to freezing and thawing
  39. Arc erosion behavior of TiB2/Cu composites with single-scale and dual-scale TiB2 particles
  40. Yb3+-containing chitosan hydrogels induce B-16 melanoma cell anoikis via a Fak-dependent pathway
  41. Template-free synthesis of Se-nanorods-rGO nanocomposite for application in supercapacitors
  42. Effect of graphene oxide on chloride penetration resistance of recycled concrete
  43. Bending resistance of PVA fiber reinforced cementitious composites containing nano-SiO2
  44. Review Articles
  45. Recent development of Supercapacitor Electrode Based on Carbon Materials
  46. Mechanical contribution of vascular smooth muscle cells in the tunica media of artery
  47. Applications of polymer-based nanoparticles in vaccine field
  48. Toxicity of metallic nanoparticles in the central nervous system
  49. Parameter control and concentration analysis of graphene colloids prepared by electric spark discharge method
  50. A critique on multi-jet electrospinning: State of the art and future outlook
  51. Electrospun cellulose acetate nanofibers and Au@AgNPs for antimicrobial activity - A mini review
  52. Recent progress in supercapacitors based on the advanced carbon electrodes
  53. Recent progress in shape memory polymer composites: methods, properties, applications and prospects
  54. In situ capabilities of Small Angle X-ray Scattering
  55. Review of nano-phase effects in high strength and conductivity copper alloys
  56. Progress and challenges in p-type oxide-based thin film transistors
  57. Advanced materials for flexible solar cell applications
  58. Phenylboronic acid-decorated polymeric nanomaterials for advanced bio-application
  59. The effect of nano-SiO2 on concrete properties: a review
  60. A brief review for fluorinated carbon: synthesis, properties and applications
  61. A review on the mechanical properties for thin film and block structure characterised by using nanoscratch test
  62. Cotton fibres functionalized with plasmonic nanoparticles to promote the destruction of harmful molecules: an overview
https://doi.org/10.1515/ntrev-2019-0010
Keywords for this article
Graphene oxide; Multi-walled carbon nanotubes; Ultrasonication; Fractal dimension; Cement; Pore structures
Creative Commons
BY 4.0

Articles in the same Issue

  1. Research Articles
  2. Investigation of rare earth upconversion fluorescent nanoparticles in biomedical field
  3. Carbon Nanotubes Coated Paper as Current Collectors for Secondary Li-ion Batteries
  4. Insight into the working wavelength of hotspot effects generated by popular nanostructures
  5. Novel Lead-free biocompatible piezoelectric Hydroxyapatite (HA) – BCZT (Ba0.85Ca0.15Zr0.1Ti0.9O3) nanocrystal composites for bone regeneration
  6. Effect of defects on the motion of carbon nanotube thermal actuator
  7. Dynamic mechanical behavior of nano-ZnO reinforced dental composite
  8. Fabrication of Ag Np-coated wetlace nonwoven fabric based on amino-terminated hyperbranched polymer
  9. Fractal analysis of pore structures in graphene oxide-carbon nanotube based cementitious pastes under different ultrasonication
  10. Effect of PVA fiber on durability of cementitious composite containing nano-SiO2
  11. Cr effects on the electrical contact properties of the Al2O3-Cu/15W composites
  12. Experimental evaluation of self-expandable metallic tracheobronchial stents
  13. Experimental study on the existence of nano-scale pores and the evolution of organic matter in organic-rich shale
  14. Mechanical characterizations of braided composite stents made of helical polyethylene terephthalate strips and NiTi wires
  15. Mechanical properties of boron nitride sheet with randomly distributed vacancy defects
  16. Fabrication, mechanical properties and failure mechanism of random and aligned nanofiber membrane with different parameters
  17. Micro- structure and rheological properties of graphene oxide rubber asphalt
  18. First-principles calculations of mechanical and thermodynamic properties of tungsten-based alloy
  19. Adsorption performance of hydrophobic/hydrophilic silica aerogel for low concentration organic pollutant in aqueous solution
  20. Preparation of spherical aminopropyl-functionalized MCM-41 and its application in removal of Pb(II) ion from aqueous solution
  21. Electrical conductivity anisotropy of copper matrix composites reinforced with SiC whiskers
  22. Miniature on-fiber extrinsic Fabry-Perot interferometric vibration sensors based on micro-cantilever beam
  23. Electric-field assisted growth and mechanical bactericidal performance of ZnO nanoarrays with gradient morphologies
  24. Flexural behavior and mechanical model of aluminum alloy mortise-and-tenon T-joints for electric vehicle
  25. Synthesis of nano zirconium oxide and its application in dentistry
  26. Surface modification of nano-sized carbon black for reinforcement of rubber
  27. Temperature-dependent negative Poisson’s ratio of monolayer graphene: Prediction from molecular dynamics simulations
  28. Finite element nonlinear transient modelling of carbon nanotubes reinforced fiber/polymer composite spherical shells with a cutout
  29. Preparation of low-permittivity K2O–B2O3–SiO2–Al2O3 composites without the addition of glass
  30. Large amplitude vibration of doubly curved FG-GRC laminated panels in thermal environments
  31. Enhanced flexural properties of aramid fiber/epoxy composites by graphene oxide
  32. Correlation between electrochemical performance degradation and catalyst structural parameters on polymer electrolyte membrane fuel cell
  33. Materials characterization of advanced fillers for composites engineering applications
  34. Humic acid assisted stabilization of dispersed single-walled carbon nanotubes in cementitious composites
  35. Test on axial compression performance of nano-silica concrete-filled angle steel reinforced GFRP tubular column
  36. Multi-scale modeling of the lamellar unit of arterial media
  37. The multiscale enhancement of mechanical properties of 3D MWK composites via poly(oxypropylene) diamines and GO nanoparticles
  38. Mechanical properties of circular nano-silica concrete filled stainless steel tube stub columns after being exposed to freezing and thawing
  39. Arc erosion behavior of TiB2/Cu composites with single-scale and dual-scale TiB2 particles
  40. Yb3+-containing chitosan hydrogels induce B-16 melanoma cell anoikis via a Fak-dependent pathway
  41. Template-free synthesis of Se-nanorods-rGO nanocomposite for application in supercapacitors
  42. Effect of graphene oxide on chloride penetration resistance of recycled concrete
  43. Bending resistance of PVA fiber reinforced cementitious composites containing nano-SiO2
  44. Review Articles
  45. Recent development of Supercapacitor Electrode Based on Carbon Materials
  46. Mechanical contribution of vascular smooth muscle cells in the tunica media of artery
  47. Applications of polymer-based nanoparticles in vaccine field
  48. Toxicity of metallic nanoparticles in the central nervous system
  49. Parameter control and concentration analysis of graphene colloids prepared by electric spark discharge method
  50. A critique on multi-jet electrospinning: State of the art and future outlook
  51. Electrospun cellulose acetate nanofibers and Au@AgNPs for antimicrobial activity - A mini review
  52. Recent progress in supercapacitors based on the advanced carbon electrodes
  53. Recent progress in shape memory polymer composites: methods, properties, applications and prospects
  54. In situ capabilities of Small Angle X-ray Scattering
  55. Review of nano-phase effects in high strength and conductivity copper alloys
  56. Progress and challenges in p-type oxide-based thin film transistors
  57. Advanced materials for flexible solar cell applications
  58. Phenylboronic acid-decorated polymeric nanomaterials for advanced bio-application
  59. The effect of nano-SiO2 on concrete properties: a review
  60. A brief review for fluorinated carbon: synthesis, properties and applications
  61. A review on the mechanical properties for thin film and block structure characterised by using nanoscratch test
  62. Cotton fibres functionalized with plasmonic nanoparticles to promote the destruction of harmful molecules: an overview
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 11.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/ntrev-2019-0010/html
Scroll to top button