The course of polymer physics is rich in philosophical content,and this paper highlights the use of reverse thinking to tackle complex issues.For example,viewing the aggregation process of polymer chains as the reverse of dissolution,preparing macroscopic polymer single crystal by crystallizing monomers before initiating polymerization,rather than crystallizing polymers directly,and shifting from free volume approaches to understand the glass transition in polymers are discussed.This article shares insights from teaching experiences that help students deeply understand the fundamentals of polymer condensed states and molecular motions through reverse thinking.

Simulating and calculating the conformation,morphology and dimensions of polymer chains,is a virtual simulation experiment project at the molecular level.It is based on the theoretical work of Nobel laureates de Gennes and P.J.Flory,and is developed through the transformation of the project team's own teaching and research achievements and collaborative research and development between teachers and students.Compared with small molecular compounds,the research methods for polymer chains are significantly different,especially in the need to use statistical methods to describe the conformation and morphology of polymer chains,and calculate the average dimensions of polymer chains.This cannot be achieved by classical physical chemistry methods.From development to teaching practice and subsequent improvements,the project naturally incorporates ideological and political elements from multiple dimensions such as Nobel Prize achievements,philosophical thoughts,scientific thinking,the history of disciplinary development,and teaching and research achievements were integrated into the update of teaching content.

1958年,应两弹一星对新材料的需求,中国科学技术大学(简称:中科大)在建校之初设置了高分子化学和高分子物理系,是我国高校中第一个成立的高分子系,分为有机合成、高分子化学、高分子物理化学和高分子物理 4个专业.首任系主任是著名军工专家,时任中国科学院化学研究所党委书记的华寿俊先生.中科大高分子系也是全世界第一个独立设置的高分子系,当时国外曾有大学闻讯来函索求我系的详细建制和教学大纲.1959年,高分子系由建系之初的 4个专业合并为高分子化学和高分子物理两个专业,由王葆仁先生和钱人元先生分别担任教研室主任.

如果从裂纹尖端的应力集中来推导材料断裂强度,会得出不合理的结论.因此格里菲思和茹柯夫分别从能量和微观化学键断裂的角度来考虑材料的断裂问题.然而对于黏弹性的高聚物材料,这些理论均一定程度上偏离实际情况,无法解释全部的实验结果.安德鲁斯通过引入一个能量损耗因子将能量与化学键断裂情况结合起来,从而得到了能反映黏弹性高聚物断裂强度的普适性理论,并成功用于解释界面粘接树脂的性能.

'Beyond oil and gas：methanol economic'could be truly realized through effective conversion of CO2 to methanol. In general Cu-based catalysts are used for synthesis of methanol by CO2 hydrogenation, and their catalytic performances are increased by adding other metals and additives. The research advances in the catalysts for synthesis of methanol from CO2 hydrogenation were reviewed. Compared with traditional Cu-Zn-Al catalysts,the new nickel-gallium catalyst could converted CO2 into methanol under low pressure／constant pressure and possessed more effective catalytic performance and higher methanol output. The synthesis of methanol through the reaction of CO2 with water and the catalyst used in the reaction were introduced. In addition,the new ideas and ways for photocatalytic reduction of CO2 to methanol were put forward.

The viscosity behavior of poly(ethylene oxide) (PEO) with different molecular weights in the water and benzene was determined respectively. It was noted that the reduced viscosity of PEO in the water deviated negatively from the linear relationship at lower concentrations in the reduced viscosity versus concentration plot. On the other hand, the reduced viscosity of PEO in benzene increased linearly with concentration even at lower concentrations. The surface tension measurements indicated that PEO could reduce the surface tension of water considerably but had no effect on the surface tension of benzene. The influence of the surface tension upon the viscosity behavior of polymer solution was notable, especially when the surface tension between the polymer solution and the pure solvent was significant. By measuring the surface tension of water and aqueous PEO solution, together with the geometric parameter of the viscometer, the influence of the surface tension upon the measurement of the flowing time could be studied quantitatively. The calculations were consistent with experimental results approximately. If t(0)* was employed to determine the viscosity of polymer solution, the influence of the surface tension upon the viscosity behavior of polymer solution could be counteracted completely and the reduced viscosity of PEO in water increased linearly with concentration just the same as PEO in benzene.

The surface property of the viscometer could be changed dramatically by the monolayer of octadecyltrichlorosilane (OTS) via the hydrogen bonding on the wall surface. As a result, the original hydrophilic surface of the viscometer became hydrophobic. The flow time of the pure solvent, therefore, reduced from 120.69s to 118.78s. By measuring the contact angle of the pure water on the glass surface, together with the geometric parameter of the viscometer, the additional pressure originated from the curved surface of the liquid could be calculated. It was noted that the decrease of the flow time of the pure water did not originate from the change of the flow model of the fluid. In fact, the no-slip condition of the fluid was still satisfied on such an occasion.

在高聚物的结构与性能课程教学中,很有必要向学生介绍高分子科学近十几年来的发展,尤其是在高分子凝聚态基本物理问题上的研究成果以及相关的新概念、新知识,特别是我国学者的贡献.本文较为详细地讨论了近年来作者在教学中介绍的几个新概念,如:动态接触浓度、单链凝聚态、凝聚缠结等.

Objective: Extracting ephedrine and berberine from the water extract of Ephedra Herba and Rhizoma Coptidis. Methods: Modified PVA was used as separating membrane and separated alkaloids. Results: A colorless ephedrine aqueous solution was obtained when extraction time was less than 8 hours; while a three constitution solution was obtained when time of extraction is over 8 hours. So is Rhizoma Coptidis. The membrane is hardly fouled. Conclusion: Purity of alkaloids from Herba Ephedra and Rhizoma Coptidis by membrane separation is Superior to that by alcoholic sediment but amount of alkaloids is reverse.

通过对高分子链的柔性、聚合物独有的熵弹性、显著的粘弹性、特有的描述链段运动的WLF方程、可能实现的大尺寸取向和小尺寸解取向、银纹、单链凝聚态、折叠链片晶和伸直链晶体、分子量的多分散性、高分子溶液特性和高聚物熔体的弹性行为等的讨论,希望能突出“高聚物的结构与性能”课程中高聚物的特点.

运用Flory凝胶化理论和Avrami法研究环氧树脂/有机蒙脱土/咪唑插层型纳米复合体系在不同温度及不同有机蒙脱土用量时的固化动力学.实验表明,随固化温度的提高,Avrami速率常数k值增大,凝胶化时间tg缩短,凝胶点后的t1/2降低,固化速率加快,当固化温度低于90℃时,Avrami指数n值为3左右,而固化温度高于90℃时,n值为2左右.有机蒙脱土的加入,使固化速率加快,但并不改变固化反应的机理,Avrami方程可以很好地描述凝胶点后的固化动力学.

LB膜的环境稳定性是它们实际应用中常见的问题。实验发现盐酸蒸汽和氨蒸汽对C60 /AA混合LB膜的周期结构都有影响 ,使衍射峰的强度逐步减弱和等同周期有所减小。酸碱处理甚至会在C60 /AA混合LB膜中造成C60 微晶的形成。

用紫外可见吸收光谱 （UV -vis）、X光电子能谱（XPS）和原子力显微镜 （AFM）对C60 /AA混合LB膜中C60 分子在LB膜中的排列作了观察 ,进一步证明了我们在第一报中确认的在混合LB膜中C60 分子不是顶在花生酸疏水部分的端头 ,而是嵌埋在花生酸分子之间。