scholarly journals Graphitic Carbon Nitride based Photocatalytic Systems for High Performance Hydrogen Production: A Review

2021 ◽  
pp. 161-192
Author(s):  
S. Sharma
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Ion Exchange ◽  
Distribution Coefficient ◽  
High Performance ◽  
Sol Gel ◽  
Exchange Capacity ◽  
Ion Exchange Capacity ◽  
E Coli ◽  
Scanning Electron

Pectin cerium(IV) iodate (PcCeI) and cerium(IV) iodate (CeI) cation ion exchange materials were synthesized via sol–gel methods. The materials were characterized by using Fourier transform infrared spectroscopy, X-ray diffractometer, thermogravimetric analysis, and scanning electron microscopy. The ion exchange capacity (IEC), thermal stability, distribution coefficient (Kd), and pH titrations were investigated to recognize the cation exchange behavior of the materials. The IEC of pectin-cerium(IV) iodate (PcCeI and cerium(IV) iodate CeI were reported as 1.80 meq/g and 0.92 meq/g, respectively. The higher distribution coefficient values of 250.01 and 219.14 mg/L confirmed the selectivity of pectin-cerium(IV) iodate hybrid ion exchanger for As3+ and Zn2+. The antibacterial activity of synthesized ion exchangers was explored for E. coli bacteria and observed relatively higher for PcCeI as compared to CeI.

scholarly journals Polymer Electrolyte Membranes Based on Nafion and a Superacidic Inorganic Additive for Fuel Cell Applications

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 914 ◽  
Author(s):  
Lucia Mazzapioda ◽  
Stefania Panero ◽  
Maria Assunta Navarra
Keyword(s):  
Fuel Cell ◽  
Ion Exchange ◽  
Proton Exchange Membrane ◽  
Sol Gel ◽  
Composite Membranes ◽  
Exchange Capacity ◽  
Proton Exchange ◽  
Thermal Transitions ◽  
Ion Exchange Capacity ◽  
Electrolyte Membranes

Nafion composite membranes, containing different amounts of mesoporous sulfated titanium oxide (TiO2-SO4) were prepared by solvent-casting and tested in proton exchange membrane fuel cells (PEMFCs), operating at very low humidification levels. The TiO2-SO4 additive was originally synthesized by a sol-gel method and characterized through x-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and ion exchange capacity (IEC). Peculiar properties of the composite membranes, such as the thermal transitions and ion exchange capacity, were investigated and here discussed. When used as an electrolyte in the fuel cell, the composite membrane guaranteed an improvement with respect to bare Nafion systems at 30% relative humidity and 110 °C, exhibiting higher power and current densities.

Synthesis and Thermal Stability of Nontransformable Tetragonal (ZrO2)0.96(REO1.5)0.04 (Re=Sc3+, Y3+) Nanocrystals

2013 ◽  
Vol 334-335 ◽  
pp. 60-64 ◽  
Author(s):  
Mohammad Reza Loghman-Estark ◽  
Reza Shoja Razavi ◽  
Hossein Edris
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm ◽  
Thermal Stability Of ◽  
Scanning Electron

Scandia, yttria doped zirconia ((ZrO2)0.96(REO1.5)0.04(RE=Sc3+, Y3+)) nanoparticles were prepared by the modified sol-gel method. The microstructure of the products was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Thermal stabillity of SYSZ nanocrystals were also investigated. The SYSZ nanocrystals synthesized with EGM:Zr+4mole ratio 4:1, calcined at 700°C, have average diameter of ~20 nm.

scholarly journals Oxometalate-Glass Composites and Thin Films

1990 ◽  
Vol 180 ◽  
Author(s):  
Karin Moller ◽  
Thomas Bein ◽  
C. Jeffrey Brinker
Keyword(s):  
Thin Films ◽  
Ion Exchange ◽  
Sol Gel ◽  
Composite Films ◽  
Exchange Capacity ◽  
Exafs Spectroscopy ◽  
Gel Formation ◽  
Ion Exchange Capacity ◽  
Glass Composites ◽  
Exchange Properties

ABSTRACTNew glass-composites with ion exchange properties have been developed. Ammonium 12-molybdophosphate (AMP) (NH4)3PMo12O40, and ammonium 12-tungstophosphate (AWP) (NH4)3PW12O40, known for their ion exchange capabilities, are included either in preformed aerogels with defined pore size, or are added to sol-gel mixtures during the process of gel formation. Characterization is carried out by FTIR, Raman and EXAFS spectroscopy. Ion exchange capacities for the oxometalate precursors are determined for silver and rubidium and are compared to those of the glass composites. Glass composites show high ion exchange capacity, but some portion of the metalate complexes leaches from the glass during the procedure. This is in contrast to thin composite films, which have almost no porosity and do not show loss of metalate. EXAFS spectroscopy demostrates that the oxometalate microstructure is maintained in glass composites and that rubidium ions after ion exchange in glasses occupy similar cation positions as in the precursor compounds.

scholarly journals Using of Clay as Heterogeneous Catalysts for Organic Syntheses; A Review

2021 ◽  
pp. 32-36
Author(s):  
Enas A. Almadani ◽  
Farah Haron ◽  
Dala M Ibrahim
Keyword(s):  
Thermal Stability ◽  
Ion Exchange ◽  
Heterogeneous Catalysts ◽  
Low Cost ◽  
Exchange Capacity ◽  
Cyclization Reactions ◽  
Ion Exchange Capacity ◽  
Environmental Friendly ◽  
Oxidation Of Alcohols ◽  
Esterification Reactions

Clay and clay modified catalysts have been widely used to catalyze various types of organic reactions such as esterification reactions, isomerization reactions, cyclization reactions, oxidation of alcohols, dehydrogenation, epoxidation and several more. Due to its favorable properties such as low cost, thermal stability, selectivity, large surface area, ion exchange capacity, easily separated, as well as environmental friendly. This paper reviewed some recent studies on the using of clay and modified clay as catalyst for the production of esters.

Preparation and Synthesis of Functional Silica-Nafion Composite Materials

2012 ◽  
Vol 496 ◽  
pp. 310-313 ◽  
Author(s):  
Yu Yuan Zhi ◽  
Kai Gu ◽  
Hui Qin Lian ◽  
Xiu Guo Cui
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ionic Conductivity ◽  
Physical Properties ◽  
Linear Expansion ◽  
Composite Membranes ◽  
Exchange Capacity ◽  
Ion Exchange Capacity ◽  
Functionalized Mesoporous Silica ◽  
Scanning Electron

In this study, a series of sulfonic-functionalized mesoporous silica (SMS) were synthesized and SMS-Nafion composites membranes were fabricated. The morphology of SMS was characterized by scanning electron microscopy and BET. The physical properties of SMS and composites membranes were tested in terms of ion-exchange capacity, linear expansion, and ionic conductivity. The results showed that the morphology of SMS influenced their physical properties as well as the properties of SMS-Nafion composite membranes.

Thermally Stable Polyimide/Silica Hybrid: Synthesis, Characterization and Optical Nonlinearity

2010 ◽  
Vol 123-125 ◽  
pp. 1275-1278
Author(s):  
Guang Yu Wu ◽  
Cheng Yao ◽  
Feng Xian Qiu
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
High Performance ◽  
Nonlinear Optical ◽  
Sol Gel ◽  
Optical Nonlinearity ◽  
29Si Nmr ◽  
Scanning Calorimetry ◽  
Excellent Thermal Stability ◽  
Electro Optic

An intercalation nonlinear-optical (NLO) polyimide was synthesized based on the 3,3’, 4,4’- Bisphenyltetracarboxylic (BPDA) and [(6-nitrobenzothiazole-2-yl)diazenyl]phenyl-1,3- diamine (NBADA). Then, hybrid polymer was synthesized by the sol-gel technique. FT-IR spectroscopy and 29Si NMR were used to characterize the structure of the hybrid. The results revealed that Q3, Q4 and T3 are the major microstructure elements in forming a network structure. The surface morphology, particle size, crystallinity and the thermal stability of the hybrid were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). DSC and TGA results showed that the glass transition temperature (Tg) and the decomposition temperature (Td) at 5% mass loss were 243, 359°C and 355, 456°C, respectively. These results showed that the hybrid material had excellent thermal stability than the pure polyimide. The electro-optic coefficients of nonlinear optical polyimide and hybrid were measured at the wavelength of 832 nm. The electro-optic coefficients were 22 and 19pm/V (poling voltage of 3.8KV, 210°C) and the values remained well (retained＞93% for more than 100h). The results suggest that the materials have potential applications for high performance optical device.

Research on Characterization and Application of High-Performance Ion Exchange Material

2013 ◽  
Vol 652-654 ◽  
pp. 1704-1709
Author(s):  
Qiong Qiong Liu ◽  
Xin Tan ◽  
Xiao Long Shao
Keyword(s):  
Ion Exchange ◽  
High Performance ◽  
Ammonia Nitrogen ◽  
Exchange Capacity ◽  
Raw Material ◽  
Ammonium Ion ◽  
Ion Exchange Capacity ◽  
Feature Evaluation ◽  
Modification Process ◽  
Exchange Material

The object of this research is to investigate the removal of nitrogen in the form of ammonium ion (NH4+-N) from aqueous solutions using Na-form of high-performance ammonium ion-exchange material. The Chinese Kaolin from the province of Guangzhou is used as the raw material and modified to prepare the ion-exchange materials. According to CEC measurement, the obtained ammonium ion-exchange material had an ammonium ion exchange capacity greater than 75mgNH4+-N/g and can be used to remove ammonia nitrogen in water treatment. In this paper, several surface feature evaluation methods（SEM、XPS、IR）are used to discuss and analyze the modification process of kaolin and the action mechanism and modification results of the ammonia ion exchange material.

Synthesizing selenium- and silver-substituted hydroxyapatite-based bone grafts and their effects on antibacterial efficiency and cell viability

2018 ◽  
Vol 63 (3) ◽  
pp. 291-300
Author(s):  
Bunyamin Aksakal ◽  
Mehtap Demirel ◽  
Zeynep A. Sinirlioglu
Keyword(s):  
Electron Microscopy ◽  
Cell Viability ◽  
Sol Gel ◽  
Control Group ◽  
Gram Positive ◽  
Gram Negative ◽  
X Ray ◽  
E Coli ◽  
Scanning Electron

Abstract Hydroxyapatite (HA)-based biografts with selenium (Se) and silver (Ag) substitutions were synthesized using the sol-gel method. The synthesized HA-based biografts at various Se and Ag quantity ratios (wt%) were characterized via Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-Ray spectroscopy (EDX). Escherichia coli (JM103) and Gram-positive Staphylococcus aureus (ATCC29293) bacteria were used for the cell viability tests by performing the MTT assay. During antibacterial tests, it was determined that the synthesized biografts showed significant antimicrobial activity on E. coli and S. aureus; however, some materials were effective on Gram-negative E. coli, but had no effect on Gram-positive S. aureus. In vitro cell viability tests revealed that some of the synthesized biografts such as H30Ag10Se15 and H40Ag20Se10 provided the highest cell viability rates compared to those in the control group.

Physicochemical Properties of SiO2/PVDF Ion-Exchange Membranes

2012 ◽  
Vol 531 ◽  
pp. 320-323
Author(s):  
Xing Tao Zuo ◽  
Zhao Dong Tian ◽  
Shui Li Yu
Keyword(s):  
Thermal Stability ◽  
Ion Exchange ◽  
Physicochemical Properties ◽  
Vinylidene Fluoride ◽  
Exchange Capacity ◽  
Anion Exchange Membranes ◽  
Ion Exchange Capacity ◽  
Blending Method ◽  
Poly Vinylidene Fluoride ◽  
Different Content

Poly(vinylidene fluoride)(PVDF)-SiO2anion-exchange membranes was prepared by blending method with the avoidance of chloromethylation. Various membranes were prepared with different content of SiO2nanoparticles. These membranes were extensively characterized for their surface morphology, thermal stability, tensile properties, water content and permselectivity property using SEM, TGA, water uptake and ion exchange capacity measurements. It was found that physicochemical properties of the PVDF/SiO2membranes were found to be highly dependent on the SiO2nanoparticles content in the membrane matrix.

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