Growth of ramification-like ZnO rods in the presence of polyaniline

To obtain new materials with synergetic or complementary behaviors, polyaniline composite filled with ZnO rods in ramification-like structure was prepared by a hydrothermal approach. Comparative experiments of ZnO preparation in the presence of some metal ions were also carried out. The results indicated that the morphology of ZnO was strongly affected by the preparation condition. The method to grow ZnO rods in the presence of polyaniline offers a simple approach to obtain polyaniline composite filled with linear ZnO structure. The results of X-ray photoelectron spectroscopy show that the strong interaction between ZnO and polyaniline possibly exists to cause the charge transfer.     

探针反应和FTIR法研究Pt与L型沸石的相互作用

探针反应和ＦＴＩＲ法研究Ｐｔ与Ｌ型沸石的相互作用董家禄,朱建华,须沁华,张婕,刘大壮（南京大学化学系,南京,２１０００８）（郑州工学院化工系,郑州,４５０００２）关键词Ｐｔ／Ｌ沸石,沸石催化剂,异丙醇分解反应,Ｐｔ－载体相互作用Ｐｔ的分散度和电子状态...     

Dependence of equilibrium constants ofL-valine on ionic strength according to Guggenheim,Scatchard and Pitzer models

Summary A systematic study of the dependence of acid-base stoichiometric constants on the ionic strength has been carried out for the aminoacidL-valine in ClK and BrK solutions. The observed dependence has been interpreted by using Guggenheim, Scatchard and Pitzer models for the activity coefficients of the species involved in the equilibria.

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Die Abhängigkeit von Gleichgewichtskonstanten desL-Valin von der Ionenstärke entsprechend den Modellen von Guggenheim, Scatchard und Pitzer

Zusammenfassung Es wurde anL-Valin in KCl- und KBr-Lösungen eine systematische Studie der Abhängigkeit der Säure-Base-Stöchiometrie von der Ionenstärke durchgeführt. Die beobachteten Abhängigkeiten wurden aufgrund der nach den Modellen von Guggenheim, Scatchard und Pitzer erhaltenen Aktivitätskoeffizienten der an den Gleichgewichten beteiligten Spezies interpretiert.

     

化工工人体内微量元素积累与健康的关系

论述了化工作业工人长期接触有害元素会引起体内有害元素积蓄，微量元素平衡失调，产生潜在的职业危害，建议定期对临床尚未发现中毒现象的作业工人进行体内微量元素情况监控，以预防职业中毒。并提出采用适当补充某些必需元素的方法，可预防这种危害。     

SiO2·(CO)n(n=1～2)结构和属性的理论研究

用密度泛函理论详细地研究了SiO2·(CO)n(n=1～2)的结构和属性.研究表明,SiO2·CO是一个T形的具有C2v对称性的分子,SiO2·(CO)2具有C2对称性的分子;频率计算结果与实验值一致,CO在与SiO2成键过程中,C-O伸缩振动频率有所增加,说明静电势在复合过程中起了重要作用;基组重叠误差(BSSE)修正在计算相互作用能时不可忽视,相互作用能和解离能的计算以及NBO分析表明,SiO2·(CO)2中的SiO2与CO之间的作用相对SiO2·CO来说较弱;SiO2和CO2与CO的成键特点不同,主要是缘于SiO2与CO2的能隙不同.     

Synthesis, characterization and thermal analysis of polyaniline/ZrO2 composites

Conducting polyaniline-zirconium dioxide (PANI/ZrO₂) composites were synthesized by ‘in situ’ deposition technique in the presence of hydrochloric acid (HCl) as dopant by adding the fine grade powder (average particle size of approximately 20 nm) of ZrO₂ into the polymerization reaction mixture of aniline. The composites obtained were characterized by infrared spectra (IR) and X-ray diffraction (XRD) and thermogravimetric analysis (TGA). TG curves and DTG curves of the composites suggest that the thermal degradation process of PANI/ZrO₂ composites proceeds in two-steps and the composites are more thermally stable than that of the pure PANI. The improvement in the thermal stability for the composites is attributed to the interaction between PANI and ZrO₂, which restricts the thermal motion of PANI chains and shields the degradation of PANI in the composites.     

Studies on the interactions between anionic surfactants and polyvinylpyrrolidone: Surface tension measurement, 13C NMR and ESR

 The interaction between anionic surfactants and polyvinylpyrrolidone (PVP) are investigated using ¹³C NMR, ESR spectroscopy and surface tension measurements at the air/water interface. The behavior of single-chained surfactant, sodium dodecyl sulphonate (AS), is compared with that of the double-chained surfactant, sodium bis(2-ethylhexyl) phosphate (NaDEHP). The results showed that a surfactant–polymer complex of “necklace and head structure” is formed in AS aqueous solutions in the presence of PVP due to the hydrophobic interaction between PVP and AS. The AS micelles nucleate on the polymer hydrophobic sites, and the mobility of the AS head groups is not affected. But, for NaDEHP surfactant, it was found that PVP is little effective in influencing the monomer–micelle equilibrium and no surfactant– polymer complex formed in the NaDEHP aqueous solution. Received: 8 May 1996 Accepted: 14 August 1997     

Tween-20与牛血清白蛋白的相互作用

通过表面张力和等温滴定量热方法，研究了非离子表面活性剂Tween-20与牛血清白蛋白(BSA)的相互作用. 结果表明，BSA与Tween-20的相互作用较弱，当Tween-20浓度增大时，能将吸附于表面上的BSA分子取代. BSA/Tween-20混合体系的性质随温度的变化趋势与单一非离子型表面活性剂相似. BSA浓度在3.7×10^-5～11.1×10^-5 kg•L^-1范围内，Tween-20的cmc不随BSA浓度的变化而变化. 当Tween-20的含量一定时，Tween-20与BSA相互作用过程的热效应也与BSA 的浓度无关. BSA/Tween-20混合体系的热力学参数表明， BSA的存在使Tween-20的cmc减小，体系的熵变增大.     

XRD法研究CrO3与NaY、NaM分子筛的表面相互作用

负载于多孔性、高比表面载体上的三氧化铝是重要的工业催化剂，多年来人们对催化剂中Croa的存在状态以及与载体的相互作用进行了广泛的研究［‘－4］，发现CrO。能在载体表gn散成非晶相的表面化合物，非晶相Cr（VI）具有较高的催化活性．我们曾经对MoO。／NaY，MoO。／NaM体系进行过系统的研究，发现MOO。与分子筛载体间存在强表面相互作用［’］．在此研究基础上，选择了CrO3／NaY、CrO。／NaM体系，采用XRD法对上述体系进行了研究．结果表明170oC下晶相CrO。能在NaY、NaM分子筛上自发分散成非晶相Cr（VI），且分散量大．C…