CBE GROWTH OF GAAS/GAAS, GAAS/SI AND ALGAAS/GAAS USING TEG, ASH3 AND AMINE-ALANE PRECURSORS

The growth of high quality AlGaAs by CBE bas been limited by the high levels of carbon and oxygen contamination. The use of alane based precursors offers a significant reduction in such contamination. We report for the first time the CBE growth of AlxGa1-xAs from triethylgallium, dimethylethylamine-alane and arsine, and compare with. growth from triethylgallium, trimethylamine-alane and arsine. Some preliminary results of work on the CBE growth of GaAs on silicon will also be reported.

Concise synthesis of novel practical sulfamide-amine alcohols for the enantioselective addition of diethylzinc to aldehydes

Novel sulfamide-amine alcohol ligands were designed using a grafting strategy and synthesized from readily available starting materials via a simple, efficient method. The key features of these ligands for the asymmetric addition of diethylzinc to aldehydes included stability, enhanced effectiveness without using Ti((OPr)-Pr-i)(4), suitability for a variety of aldehydes, the ability to operate at room temperature, and selectability to afford either absolute configuration products with enantiomeric excess up to >99%.

Synthesis of novel star-like hyperbranched polymers with poly(amido amine) core and poly(L-lysine) shell

Hyperbranched poly(amido amine)s containing vinyl and hydroxyl groups were successfully synthesized via Michael addition polymerization of triacrylamide (TT) and 3-amino-1,2-propanediol (APD) with equal molar ratio in feed. H-1, C-13 and HSQC NMR techniques were used to clarify the structure of hyperbranched polymers and polymerization mechanism.

Synthesis of isomeric bis(amine anhydride)s for novel poly(amine imide)s by Pd-catalyzed amination of 4-chlorophthalic anhydride

Two novel bis(amine anhydride) monomers, N,N'-bis(3,4-dicarboxyphenyl)-1,4-phenylenediamine dianhydride I and N,/N'-bis(3,4-dicarboxyphenyl)-1,3-phenylenediamine dianhydride 11, were prepared via palladium-catalyzed amination reaction of 4-chloro-N-methylphthaliniide with 1,4-phenylenediamine or 1,3-phenylenediamine, followed by alkaline hydrolysis of the intermediate bis(amine imide)s and subsequent dehydration of the resulting tetraacids. A series of new poly(amine imide)s were prepared from the synthesized dianhydride monomers with various diamines in NMP via conventional two-step method.

Novel aliphatic poly(ester-carhonate) with pendant allyl ester groups and its folic acid functionalization

A series of novel poly(ester-carbonate)s bearing pendant allyl ester groups P(LA-co-MAC)s were prepared by ring-opening copolymerization Of L-lactide (LA) and 5-methyl-5-allyloxycarbonyl-1,3-dioxan-2-one (MAC) with diethyl zinc (ZnEt2) as initiator. NMR analysis investigated the microstructure of the copolymer. DSC results indicated that the copolymers displayed a single glass-transition temperature (T-g), which was indicative of a random copolymer, and the Tg decreased with increasing carbonate content in the copolymer.

Green synthesis of 1-2 nm gold nanoparticles stabilized by amine-terminated ionic liquid and their electrocatalytic activity in oxygen reduction

Stable gold nanoparticles with average size 1.7 nm synthesized by an amine-terminated ionic liquid showed enhanced electrocatalytic activity and high stability.

Reversed micellar solubilization extraction and separation of thorium(IV) from rare earth(III) by primary amine N1923 in ionic liquid

The extraction behavior of thorium(IV) sulfate by primary amine N1923 in imidazolium-based ionic liquid (IL) namely 1-octyl-3-methylimidazolium hexafluorophosphate ([C(8)mim]PF6) was systematically studied in this paper. Results showed that the extraction behavior was quite different from that using conventional solvent as diluent. A reversed micellar solubilization extraction mechanism was proposed for the extraction of thorium(IV) by N1923/[C(8)mim]PF6 via slope analysis method and polarized optical microscopy (POM)/transmission electron microscopy (TEM) observation. The salt-out agent, Na2SO4, was demonstrated to prompt this extraction mechanism.

Extraction kinetics of thorium(IV) with primary amine N1923 in sulfate media using a constant interfacial cell with laminar flow

Extraction kinetics of thorium(IV) with primary amine N1923 in sulfate media has been investigated by a constant interfacial cell with laminar flow. Studies of interfacial tension and effects of the stirring rate, temperature, and specific interfacial area on mass transfer rate show that the most probable reaction zone takes place at the liquid-liquid interface. According to the experimental data correlated as a function of the concentration of the relevant species involved in the extraction reaction, the rate equation of extracting thorium has been obtained as follows: -d[Th(IV)]((o))/dt = 10(-3.10)center dot[Th(IV)](0.89)center dot[(RNH3)(2)SO4](0.74).