PABA疏水缔合水溶性共聚物溶液的合成与性能研究

本文根据高分子的分子设计原理，合成了带苯基的疏水单体N－苯基对正丁基丙烯酰胺（BBAM）。采用自由基胶束共聚的方法制备了水溶性丙烯胺／N－苯基对正丁基丙烯酰胺（BBAM）疏水缔合型共聚物（PABA）。研究了共聚物溶液的性能及影响因素。结果表明，随共聚物溶液浓度的增加，在临界缔合浓度以上，分子间缔合大量形成，水溶液表现粘度迅速增加，表现出明显的疏水缔合行为，与HPAM相比有优异的抗盐性。     

Inorganic—Organic Hybrid 18—Molybdodiphosphate Nanoparticles Bullk—modified Carbon Paste Electrode and Its Electrocatalysis

A kind of inorganic‐organic hybrid 18‐molybdodiphosphate nanoparticles ([(C₄H₉)₄N]₆P₂Mo₁₈Q₆₂·4H₂O) was firstly used as a bulk‐modifier to fabricate a three‐dimensional chemically modified carbon paste electrode (CPE) by direct mixing. The electrochemical behavior of the solid nanoparticles dispersed in the CPE in acidic aqueous solution was characterized by cyclic and square‐wave voltammetry. The hybrid 18‐molybdodiphosphate nanoparticles bulk‐modified CPE (MNP‐CPE) displayed a high electrocatalytic activity towards the reduction of nitrite, bromate and hydrogen peroxide. The remarkable advantages of the MNP‐CPE over the traditional polyoxometalates‐modified electrodes are their excellent reproducibility of surface‐renewal and high stability owing to the insolubility of the hybrid 18‐molybdodiphosphate nanoparticles.     

Synthesis and properties of new crystalline poly(arylene ether nitriles)

Crystalline poly(arylene ether nitrile) could be prepared by the polycondensation of 2,6-dihalobenzonitrile with resorcinol at 200°C in N-methylpyrrolidone in the presence of sodium carbonate. A reaction temperature of at least 200°C was necessary to attain high molecular weight polymer. Spectral data indicated that the polymer had the structure of a poly(meta-phenylene ether) with pendent nitrile groups on every other phenylene unit. Despite this structure, the crystallinity and the crystallization rate of the polymer were greater than those of the corresponding polymer with a para-linked structure. The glass transition temperature and the melting temperature of the polymer were almost the same as those of poly(etheretherketone) (PEEK^TM). A series of other new poly(arylene ether nitriles) were also examined. The polymers derived from 4,4′-biphenol, dihydroxytetra-phenylmethane, dihydroxydiphenylsulfone, and 1,5-isoquinolinediol had high glass transition temperatures. The poly(arylene ether nitriles) exhibited excellent tensile strength compared with the corresponding ketone- or sulfone-containing polymers. Comparing the three different kinds of polymers containing the same bisphenol units, the order of glass transition temperature was found to be sulfone- > nitrile- > ketone-containing polymers, while the order of tensile strength was nitrile- > ketone- > sulfone-containing polymers. The excellent mechanical properties are attributable to dipole-dipole interactions of nitrile groups. © 1993 John Wiley & Sons, Inc.     

Composting of urban solid residues (USR) by different dispositions

The thermal behavior and non-isothermal kinetics of thermal decomposition of three different kinds of composting of the USR like: stack with drilled PVC tubes (ST), revolved stack (SR) and stack with material of structure (SM), from the usine of composing of Araraquara city, Săo Paulo state, Brazil, within a period of 132 days of composting were studied. Results from TG, DTG and DSC curves obtained on inert atmosphere indicated that the cellulosic fraction present, despite the slow degradation during the composting process, is thermally less stable than other substances originated from that process. Due to that behavior, the cellulosic fraction decomposition could be kinetically evaluated through non-isothermal methods of analysis. The values obtained were: average activation energy, Ea=248, 257 and 259 kJ mol^-1 and pre- exponential factor, logA=21.4, 22.5, 22.7 min^-1, to the ST, SR and SM, respectively. From Ea and logA values and DSC curves, Málek procedure could be applied, suggesting that the SB (Šesták-Berggren) kinetic model is the appropriated one to the first thermal decomposition step. This revised version was published online in July 2006 with corrections to the Cover Date.     

Preliminary study on dual fluorescence behavior of porphyrin

It is well known that porphyrin derivatives play a key role in the primary process of photo-synthesis[1], in which porphyrins directly absorb the sunlight or indirectly acquire excitation en-ergy from light-harvesting antenna system to reach their excited state, and then donate electrons to quinone acceptors to yield a series of charge-separated species. In general, only first singlet ex-cited state of porphyrins is involved in energy transfer process[2]. However, highly excited state (S2 stat…     

酶联免疫吸附分析法测定水样中的阿特拉津

应用阿特拉津半抗原衍生物共价交联于载体蛋白分子上，制成免疫抗原，经免疫得到高质量的兔抗阿特拉津抗血清。经条件优选，建立了测定阿特拉津的酶联吸附分析竞争法，测定性范围为０．０５－５．００μｇ／Ｌ，最低检出限仅为０．０１８－０．０２２μｇ／Ｌ，且精密度高，特异性强。     

Syntheses and Studies of PEG-b-PNIPA Block Polymers

ＳｙｎｔｈｅｓｅｓａｎｄＳｔｕｄｉｅｓｏｆＰＥＧ┐ｂ┐ＰＮＩＰＡＢｌｏｃｋＰｏｌｙｍｅｒｓＣＡＯＷｅｉ－ｘｉａｏ＊＊ａｎｄＺＨＡＮＧＴａｏ（ＣｏｌｅｇｅｏｆＣｈｅｍｉｓｔｒｙａｎｄＭｏｌｅｃｕｌａｒＥｎｇｉｎｅｒｉｎｇ，ＰｅｋｉｎｇＵｎｉｖｅｒｓｉｔ...     

Influences of Triton X-100 on Hemoglobin Behaviors in Hemoglobin/Acyclovir/Triton X-100/H2O System

The influences of Triton X-100 on hemoglobin （Hb） behaviors were studied by the methods of UV-Vis spectrum, fluorescence spectrum, HPLC, conductivity, zeta potential and negative-staining transmission electron microscope in Hb/acyclovir/Triton X-100/H2O system. With the increase of Triton X-100 concentration in the system, the percentage of the free acyclovir increased from 58%--63% to 90%--94%. The static quenching constant and the association number of acyclovir to Hb decreased. The fluorescence spectrum, conductivity, zeta potential, fluorescence polarization and negative-staining morphology of Hb tended to recover to those of the original state of Hb in the same concentration of Hb. The interaction between Triton X-100 and Hb is stronger than that between acyclovir and Hb. Most Triton-X-100 was associated with Hb at low Triton X-100 concentration. But the interaction of Triton X-100 with Hb was apparently dominant in high Triton X-100 concentration. The Hb structure was unfolded and finally denatured.     

酞侧基聚芳醚酮的热学性能

酞侧基聚芳醚酮的热学性能谢红卫，李滨耀（中国科学院长春应用化学研究所长春１３００２２）关键词酞侧基聚芳醚酮，ｐｖＴ行为，导热系数，定压比热容酞侧基聚芳醚酮（ＰＥＫ－Ｃ）具有较高的玻璃化转变温度，其流变加工性能和力学性能已被广泛研究［１～３］，被证明是...     

白藜芦醇的电化学行为及其与DNA的相互作用

采用电化学方法研究了白藜芦醇在pH=2~13的缓冲溶液中的电化学行为、抗氧化能力及其与DNA的相互作用. 研究结果表明， 在2.011的溶液中, 白藜芦醇产生的P4和P5波分别是其二价和三价阴离子的还原波. 在最佳实验条件下, 微分脉冲极谱图上IP3在8.0×10-8~2.0×10-6 mol/L范围内与白藜芦醇的浓度呈线性关系, 检出限为4×10-8 mol/L. 将该法用于中药虎杖中白藜芦醇含量的测定, 结果与高效液相色谱法一致.