Band 41, Heft 1

Polyimide membranes and network hybrid membranes exhibit high permeability despite good thermal and chemical stability, and high selectivity in gas mixture separation. In this study, the effect of nanoparticle distribution on the network polymer network, and changes in permeability, selectivity, and structure of the composite lattice membrane are investigated. According to the obtained permeability results, this increase in permeability was due to the increase of polymer network free volume and the formation of cavities in the nanoparticle-polymer interface. The significant results were that the permeability growth of gases with larger molecular size such as methane and nitrogen was higher than other gases. A comparison of the permeability growth of gases with the increasing volume fraction of nanoparticles confirms the dominance of the molecular sieve mechanism and the type of membrane transport mechanism change over polyimide and network Hybrid.

Rapid escalation in energy demand and pressure over finite fossil fuels reserves with augmenting urbanization and industrialization points towards adoption of cleaner, sustainable and eco-friendly sources to be employed. Solar cell devices known for efficient conversion of solar energy to electrical energy have been attracting scientific community due to their remarkable conformity with the principles of green chemistry. The future candidacy of solar cells is expressed by their efficient conversion. Such a great potential associated with solar cells has instigated research since many decades leading to the emergence of a wide myriad of solar cells devices with novel constituent materials, designs and architecture reflected in form of three generations of the solar cells. Considering the cleaner and sustainability aspects of the solar energy, current review has systematically compiled different generations of solar cells signifying the advancements in terms of architecture and compositional parameters. In addition to the chronological progression of solar cells, current review has also focused on the innovations done in improvement of solar cells. In terms of efficiency and stability, photovoltaic community is eager to achieve augmented efficiencies and stabilities for using solar cells as an alternative to the conventional fossil fuels.

This review covers over 20 monomeric platinum complexes of Pt{η 2 -P(X) n P}Cl 2 ( n  = 9–15, 17, 19) type. The chelating P,P-donor ligands create wide varieties of the metallocyclic rings: 12-membered (PC 9 P, PC 3 NCNC 3 P), 13-membered (PC 3 NC 2 NC 3 P), 14-membered (PC 11 P, PO(SiO) 5 P, PC 2 OC 2 OC 2 OC 2 P), 15-membered (PC 12 P), 16-membered (PCOC 9 OCP), 17-membered (P(C 2 O) 4 C 2 P), 18-membered (PC 2 OC 9 OC 2 P, PC 4 NC 2 NC 2 NC 4 P), 20-membered (P(C 2 O) 5 C 2 P), and 21-membered (POC 2 NC 10 NC 2 OP). For these complexes the most common is a predominantly cis -arranged with 17 examples and only four examples with trans -configuration. The total mean values of Pt–L bond distances in the complexes with cis - versus trans -configuration are: 2.252 Å (P trans to Cl), 2.355 Å (Cl trans to P) vs 2.288 Å (P trans to P), and 2.304 Å (Cl trans to Cl). There are examples which exist in cis - and trans -isomeric forms and distortion isomers. A brief survey on the structural data of almost 180 examples of Pt{η 2 -P(X) n P}Cl 2 ( n  = 1–8) type complexes is added and discussed.

The complexity of boron species in aqueous solution becomes the bottleneck in development of boron resources from brine. The concentrations of different boron species and transformation mechanism among boron species are mainly affected with the total boron concentration, temperatures, pH of the solution, and cations in the solution. The change trends for concentration of total boron in the complicated aqueous solution can be obtained with the phase equilibrium results, but the accurate concentration of boron species in the solution cannot be obtained. The metastable zone width (MZW) of borates and H 3 BO 3 changed with the concentrations of impurity ions, the stirring rate, cooling rate, and original temperature for the saturated solution. The Pitzer model is the effective method to calculate the concentration of boron species. More thermodynamic data at temperatures below and above 298.15 K are needed for model parameterization. The main problems existed in the systems containing boron species were summarized, and the future development direction is also discussed. The progresses on boron species in the aqueous solution can provide fundamental data in the comprehensive exploitation of the brine boron resource.