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91.
《Current Applied Physics》2015,15(3):356-362
This paper reports a new method for fabricating two-dimensional ZnO nanorod patterns. A water soluble mixture of poly(vinyl alcohol)-N-methyl-4(4′-formylstyryl)pyridinium methosulfate acetal (PVA-Sbq) and zinc acetate (ZnA) was used as a negative photoresist to produce the desired patterns using conventional photolithography. Hydrothermally-grown ZnO nanorods were grown selectively on the calcined PVA-Sbq/ZnA patterns. The appropriate concentration of PVA-Sbq and ZnA that can produce the desirable seed layer pattern was determined experimentally. Furthermore, the effects of the calcination time on the morphology and vertical alignment of ZnO nanorods were investigated. The vertically-aligned ZnO nanorods were generated by sufficient calcination of the patterned seed layer. On the other hand, the aspect ratio of ZnO nanorods decreased slightly with increasing calcination time. This new approach provides a simple and cost-effective method for fabricating ZnO nanorod patterns which can be beneficial in various solid-state devices and optoelectronic applications. 相似文献
92.
R. HekmatShoar S. Souri F. Faridbod 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1457-1461
An efficient process that converts 2-hydroxybenzaldehyde and their derivetives to chromene derivatives via intramolecular Wittig reaction is described. 相似文献
93.
94.
A new and efficient method of converting acid hydrazides 1 to the corresponding N,N′‐diacylhydrazines 2 under microwave irradiation and in solvent‐free conditions has been described. 相似文献
95.
《合成通讯》2013,43(22):3449-3454
ABSTRACT A series of substituted 5-oxo-1,2,3,4,5,6,7,8-octahydroquinoline derivatives have been synthesized from 5,5-dimethyl-1,3-cyclohexane-dione (dimedone) and 1,3-diaryl-2-propen-1-one in DMF at 80°C in the presence of ammonium acetate with high yields (64–98%), the structure of the product was confirmed by X-ray analysis. 相似文献
96.
《合成通讯》2013,43(24):4477-4482
Abstract Regioselective synthesis of α‐iodoacetates from alkenes, ammonium acetate, and iodine in acetic acid is reported. The reaction is facile, fast, environmentally, friendly, and cost effective. α‐Iodoacetates are obtained from both acyclic and cyclic alkenes in high yields ranging from 80–95% within 10–20 min. 相似文献
97.
Vinyl acetate radical emulsion polymerization in water with GF51 silane co-monomer was performed by semi continuous way. The GF51 impacts on dispersion rheology as well on films and bonding strength properties were determined. It should be stated that even low quantities of GF51 (up to 6% from VAc) determined high viscosity of dispersions. The GF51 modified films have low water absorption and high affinity to glass. Molecular mass and thermal properties of GF51 modified polymers were determined accordingly. 相似文献
98.
Yang Sun Xiaoqing Wang Yilei Huang Zaifa Pan Lili Wang 《Journal of separation science》2013,36(14):2268-2276
Derivatization at the injection port following hollow‐fiber‐based liquid–liquid–liquid microextraction with tetramethylammonium acetate as a dual‐function reagent, i.e. an acceptor and derivatization reagent, for the determination of benzoic acid (BA) and sorbic acid (SA) in real samples by GC was developed. BA and SA were extracted from aqueous samples to an organic phase impregnated into the pores of the hollow fiber wall, and then back‐extracted to the acceptor solution located inside the lumen of the hollow fiber. Upon injection, the extracted analytes were quantitatively derivatized to their methyl esters with tetramethylammonium acetate in the GC injection port. Several parameters related to the derivatization and extraction efficiency were optimized. The linearity was satisfactory over a concentration range of 0.1–50 mg/L with r > 0.993 for both analytes. The LODs were 2.0 μg/L for SA and 20 μg/L for BA. The recoveries (83–116%) and precisions (RSDs of 1.2–11.4% (n = 3)) were examined by analyzing real spiked samples. The enrichment factors of BA and SA were 300 and 425. The results demonstrated that this is a simple, rapid, accurate, and sensitive method for the determination of BA and SA in various samples. 相似文献
99.
Gregory B. Kharas Selena M. Russell Kerrianne Trickey Daniel P. Baecher Jeffrey H. Becker Samuel Borgmeyer 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(11):1151-1154
Electrophilic trisubstituted ethylene monomers, alkyl ring‐substituted 2‐phenyl‐1,1‐dicyanoethylenes, RC6H4CH?C(CN)2 (where R is 2‐methyl, 3‐methyl,4‐methyl, 4‐ethyl, 4‐isopropyl, 4‐butyl, and 4‐t‐butyl), were synthesized by piperidine catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and malononitrile, and characterized by CHN elemental analysis, IR, 1H‐ and 13C‐NMR. Novel copolymers of the ethylenes and vinyl acetate were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C‐NMR, GPC, DSC, and TGA. High Tg of the copolymers, in comparison with that of polyvinyl acetate, indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 190–700°C range. 相似文献
100.
Several new lightweight polymer concretes derived from industrial, agricultural, and naturally occurring waste materials were investigated. Various physicomechanical properties of these materials were studied. Such inexpensive and lightweight polymer composites, which have properties superior to ordinary reinforced cement concrete, may find wide applications in building technology and related areas and may serve as better substitutes for cement. Furthermore, recycling of such wastes from various sources may help to solve the present environmental pollution problems. 相似文献