A MORPHOLOGICAL STUDY OF POLY（DIVINYLBENZENE-co-ACRYLIC ACID） IN CROSSLINKING PRECIPITATION POLYMERIZATION

Divinylbenzene-80 （DVB-80） and polar monomer acrylic acid （AA） having hydrogen bonding at a total monomer loading of 5 vol% were precipitated-copolymerized in a variety of organic solvents with 2,2＇-azobis（isobutyronitrile） （AIBN） as initiator. The experiments were investigated from a two-dimensional matrix, i.e., the actual crosslinking degree of DVB varying from 0 to 80% and the solvent composition varying from 0 to 100% of toluene mixture with acetonitrile, when the mixture of acetonitrile and toluene was used as the reaction solvent. Under various reaction conditions, six distinct morphologies including soluble polymers, swellable microgels, coagulum, irregular microparticles, and nano-/micrometer microspheres were formed and the structures of these polymer architectures were described. A morphological map was utilized to discuss the effects of both crosslinking degree of DVB and composition of solvent on the transitions between morphology domains. The results demonstrated that the microspheres are formed by an internal contraction due to the marginal solvency of the continuous phase and the crosslinking of the polymer network through the covalent bonding from DVB as well as the interchain hydrogen-bonding between the carboxylic acid units.     

动态单滴法研究乳状液液膜的稳定性

乳状液液膜作为化学分离的一种手段,自七十年代发现以来已有了许多进展,但是如何将其工业化还有许多课题有待于进一步研究.目前,除了乳状液液膜的水静态渗透性质以外,对乳状液液膜的稳定性和溶胀性质的研究主要采用搅拌法.虽然得到较好的规律性,但是搅拌法具有乳状液滴粒径分布广的弱点,对于不同的搅拌方式及条件,乳状液液膜的有效面积不同,对液膜作用的机械强度不同,因此结果会有很大差别.我们自行设计的动态单滴法实验装置,可定量地研究乳状液液膜的溶胀、稳定性及水渗透性质.     

Specific oxidation of C-14 oxygenated 4(20),11-taxadienes by microbial transformation

Three C-14 oxygenated taxanes, 2α,5α,10β,14β-tetraacetoxytaxa-4(20),11-diene (1), 2α,5α,10β-triacetoxy-14β-(2-methylbutyryloxy)taxa-4(20),11-diene (2), and yunanaxane (3), major products of callus cultures of Taxus spp., were regio- and stereoselectively hydroxylated at the 7β position by a fungus, Absidia coerulea IFO 4011. Intriguingly, when 1 was co-administered with β-cyclodextrin and incubated with the fungus cell cultures, three other compounds 5α,9α,10β,13α-tetraacetoxytaxa-4(20),11-dien-14β-ol (7), 5α,9α,10β,13α-tetraacetoxytaxa-4(20),11-dien-1β-ol (8) and 5α,9α,10β,13α-tetraacetoxy-11(15→1) abeotaxa-4(20),11-dien-15-ol (9) were obtained.     

1-(2-pyridylazo)-2-naphthol (PAN) as extractant in solid-liquid extraction of some trivalent rare earth elements

In the present paper, solid-liquid extraction behaviour of RE(III) (RE La, Ce, Pr, Nd, Sm, Gd, Dy and Yb) by the use of 1-(2-pyridylazo)-2-naphthol (PAN, HL) as an extractant in paraffin (m.p. 48 approximately 50 degrees) has been investigated at 80 +/- 0.07 degrees. The effect of equilibrium time, pH of aqueous phase, concentration of extractant in paraffin and solid diluent as well as buffer solution used on the extraction efficiency of RE(III) have been discussed. The extraction reaction is RE(3+) + 2HL(o) + Cl(-) <==> REL(2)Cl(o) + 2H(+).     

SrO—Al2O3—SiO2：Eu^3＋,Bi^3＋发光体的溶胶—凝胶法合成

制备无机固体材料大都采用高温固相反应,1971年Dislich报导了用溶胶-凝胶法制备多组份固体材料。近年来,有报导利用此法研制玻璃、玻璃陶瓷和陶瓷。我们在过去工作的基础上,合成了SrO-Al_2O_3-SiO_2:Eu~(3 ),Bi~(3 )发光体,研究了从凝胶至发光晶体的转变过程、Eu~(3 )和Bi~(3 )在SrO-Al_2O_3-SiO_2基质中的发光性质以及Bi~(3 )对 EU~(3 )的能量传递。     

液晶CPBOB吸附的STM研究

利用STM对吸附在导电基底上的液晶进行研究，能提供近原子分辨的液晶分子图象，这一创新不仅拓宽了STM的研究领域，也使STM成为研究液晶吸附的重要手段之一．根据液晶相变特征不同，样品的制备方法大致分四种情况：直接法，加热法，气相沉积法和溶剂法．无论采用以上哪种方法，     

五磷酸铽荧光光谱偏振特性的研究

本文报告了在77 K下TbP_5O_(14)中Tb~(3+)离子的~5D_4-~7F_J, 跃迁荧光光谱的偏振特性。根据退偏度的规律认定了~5D_4和~7F_J的大部分Stark能级的标号。     

Prototype of immunochromatographic assay strips using colloidal CdTe nanocrystals as biological luminescent label

Colloidal semiconductor nanocrystals have attracted considerable attention as a novel biological luminescent label. The bioinorganic conjugates of luminescent CdTe nanocrystals and protein, including CdTe/BSA (bovine serum albumin) and CdTe/MAB (mouse monoclonal antibody against hepatities B surface antigen), were formed via electrostatic/coordination self-assembly. Pure CdTe nanocrystals, CdTe/BSA and CdTe/MAB were used in the immunochromatographic assay experiments, respectively. And the results indicated that CdTe nanocrystals could be used and developed as a novel label with good stability, high sensitivity and facile determination of several analytes in immunochromatographic assay strips.