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排序方式: 共有296条查询结果,搜索用时 15 毫秒
71.
Cellulose - The synthesis of multi-function flame retardants is widely increasing to fulfill industrial and economic goals. In this work, a novel flame retardant, melamine salt of tannic phosphate... 相似文献
72.
M. H. Abdallah Y. Ramaden S. A. Jawad M. Hassan M. S. Ahmad A. M. Zihlif 《Applied Physics A: Materials Science & Processing》1995,60(5):437-440
The effect of annealing on the electrical properties and the refractive index of red mercuric iodide (HgI2) single crystals is investigated. The ac-impedance and phase angle were measured in the frequency range from 100 Hz to 10 kHz at different annealing temperatures. The ac-conductivity, dielectric constants, loss tangent and the refractive index as a function of frequency are determined. The results are discussed in terms of structural changes taking place as a result of the heat treatment of the HgI2 single crystals. 相似文献
73.
Mousa Z. Al-Noaimi Raid J. Abdel-Jalil Mustafa M. El-Abadelah Salim F. Haddad Younis N. H. Baqi Wolfgang Voelter 《Monatshefte für Chemie / Chemical Monthly》2006,137(6):745-750
Summary. In the presence of RuCl3, N-phenylamidrazone underwent oxidative cyclization into 1,4-dihydro-1-phenyl-1,2,4-benzotriazine, the structure of which is
established by spectral and X-ray diffraction data. 相似文献
74.
Tuning the performance of aqueous photovoltaic elastomer gels by solvent polarity and nanostructure development
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Heba A. Al‐Mohsin Kenneth P. Mineart Daniel P. Armstrong Richard J. Spontak 《Journal of Polymer Science.Polymer Physics》2017,55(1):85-95
In this study, a sulfonated pentablock ionomer is considered for use as an aqueous gel electrolyte in photovoltaic elastomer gels (PVEGs) containing photosensitive dyes. Depending on the casting solvent employed, these materials order into different nanoscale morphologies, some of which inherently consist of a continuous pathway through which ions and other polar species are able to diffuse, while others transform into continuous channels upon exposure to water. Here, we examine the effect of solvent polarity during film casting, vapor annealing, and liquid immersion on block ionomer morphology and PVEG photovoltaic performance. Casting the block ionomers from a mixed nonpolar/polar solvent promotes the formation of dispersed ion‐rich spherical microdomains. Alternatively, the use of a single polar solvent produces coexisting nonpolar cylinders and lamellae. Exposure of either morphology to polar solvent vapor causes the block ionomers to restructure into a lamellar morphology, whereas exposure of dispersed ion‐rich microdomains to water induces a transformation to an irregular morphology composed of continuous ionic channels, which provide an effective pathway for ion diffusion and, consequently, the highest photovoltaic efficiency. In addition to their photovoltaic efficacy, these aqueous gels possess improved mechanical properties (in terms of tensile strength and elastic modulus) in the presence of photosensitive dyes. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 85–95 相似文献
75.
Brett D. Martin Jawad Naciri Martin H. Moore Daniel A. Lowy Michael A. Dinderman Erica C. Pehrsson Banahalli Ratna 《Electrochemistry communications》2009,11(1):169-173
We describe a nanoscale gating effect by an atypical tether-containing polythiophene, [poly(thiophene-3-carboxylic acid 2-(2-(2-(2-ethoxy-ethoxymethyl sulfonate)-ethoxy)-ethoxy)-amide], referred to as poly(TP-OEG-SO4). Cyclic voltammetry data permitted us to calculate liquid-phase ion diffusivities in the polymer as a function of its oxidation state. Diffusivities are more than 350 times higher in the oxidized state versus the reduced state. As a control, poly 3′,4′-dimethyl-[2,2′;5′,2″] terthiophene (DMPT) was synthesized and characterized. On comparing both polymers in the reduced state, we find diffusivities in poly(TP-OEG-SO4) to be more than 4500 times lower than in poly(DMPT). To explain this behavior, we propose a model that features a charge-balancing mechanism by the sulfonate tethers in poly(TP-OEG-SO4), which causes nanoporous regions around the polymer main chains to be opened and closed, leading to the large observed differences in diffusivities. These data suggest that the polymer poly(TP-OEG-SO4) is evidently able to act as a reversible “nanogate” with an open pore structure when oxidized, and a closed one when reduced. 相似文献
76.
Abu Elella Mahmoud H. Abdallah Heba M. Gamal Heba Moustafa Essam B. Goda Emad S. 《Cellulose (London, England)》2022,29(13):7317-7330
Cellulose - Antimicrobial hydrogels have enticed a major concern for repairing soft tissues, particularly prohibiting bacterial infections that are frequently accompanied by impaired wound healing.... 相似文献
77.
Lund Liaquat Ali Omar Zurni Raza Jawad Khan Ilyas 《Journal of Thermal Analysis and Calorimetry》2021,143(2):915-927
Journal of Thermal Analysis and Calorimetry - This study shows multiple solutions, heat transfer characteristics, and stability analysis of the magnetohydrodynamic (MHD) flow of hybrid nanofluid... 相似文献
78.
Ehab Abdel-Latif Heba M. Metwally Eman M. Keshk Abdel-Galil M. Khalil Ali Saeed 《合成通讯》2019,49(16):1957-1986
Chemical reactivity of amino group that connected with the para position of acetanilide moiety (p-aminoacetanilide) attained more attention in chemistry. In this review article, we report the chemistry of p-aminoacetanilide and its utilization in the synthesis of azo compounds, pyrrole, imidazole, thiazole and various heterocycles of biological importance. 相似文献
79.
Heba Gaballa Jiaojiao Shang Sabrina Meier Patrick Theato 《Journal of polymer science. Part A, Polymer chemistry》2019,57(3):422-431
Glucose responsive block copolymer featuring boronic acid as a glucose responsive moiety and glycine are reported. The first block is polymerized through reversible addition–fragmentation chain transfer (RAFT) polymerization and the resulting poly(N‐acryloylmorpholine)113 (PAcM) is employed as a macro‐chain transfer agent for chain extension with pentafluorophenyl acrylate (PFPA) yielding a well‐defined PAcM113‐block‐poly(pentafluorophenyl acrylate)84 (PPFPA). The PPFPA block is then reacted with functional (3‐aminomethyl) phenyl boronic acid and glycine via post‐polymerization modification and the structure of the block copolymer is confirmed by proton nuclear magnetic resonance (NMR), 19F NMR, Fourier transform infrared, and gel permeation chromatography. By copolymerizing glycine into the polymer backbone, the relative pKa of the block copolymer is significantly lowered. The block copolymer can self‐assemble into core–shell micelles in aqueous solution and disassemble in response to glucose at the physiological pH. Furthermore, the encapsulation and release of Nile red (NR) as a hydrophobic model drug is studied under the physiological pH. The influence of the glucose concentration on the NR release from the polymeric micelles is demonstrated. These results suggested that the glucose‐responsive poly[(AcM)113‐b‐(3‐(aminomethyl)phenylboronic acid hydrochloride(‐co‐Gly)84] block copolymer has potential applications as a glucose‐responsive polymer for insulin delivery. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 422–431 相似文献
80.
P. S. Pereira Silva Raza Murad Ghalib Sayed Hasan Mehdi Rokiah Hashim Othman Sulaiman Ali Jawad 《Journal of chemical crystallography》2010,40(12):1150-1154