闭孔泡沫塑料结构与性能研究进展

综述了近年来对闭孔泡沫塑料,主要是发泡聚烯烃的结构与性能关系研究的进展。总结了有关泡沫塑料的常见结构模型以及性能结构关系的解析式表达,并介绍了常见表征泡沫塑料结构、性能的方法以及近年来出现的新的表征手段。文章讨论了近年来研究塑料泡沫结构与性能尤其是力学性能之间关系的新结果、新进展,并对研究进行了展望。     

试论高聚物结构与性能关系的三个层次

高分子物理的基本任务之一就是探求高聚物的结构与性能,揭示结构与性能之间的内在联系及其基本规律。高聚物结构与性能的关系应该包含3个层次:通过分子运动联系的"分子结构与材料性能"关系、通过产品设计联系的"凝聚态结构与制品性能"关系和通过凝聚态物理知识联系的"电子态结构与材料功能"关系。传统教材上仅讲授"结构与性能关系",有相当的局限性,需要在研究生阶段补充有关"凝聚态结构与制品性能"关系和"电子态结构与材料功能"关系的课程。     

基于产品工程理念的聚乙二醇类物质脱硫脱氮实验教学设计*

基于产品工程理念,本着以结构-性能关系为核心,将实验教学与产品工程理念相结合的原则,对聚乙二醇类物质(PEGs)脱硫脱氮实验教学进行了设计。通过实验操作和上机数据处理等方式,逐步引导学生对PEGs的结构及其萃取性能进行量化描述,建立结构-性能之间的数学关系,并对结构进行优化设计,有利于学生正确理解“结构预测性能”和“性能优化结构”等问题,既拓展了教学内容,又使学生掌握到更多的知识和技能,符合专业的发展方向,进而达到了促进教学的目的。     

电化学储能及传感器用氮化碳基复合材料设计策略

理性设计的氮化碳(C_3N_4)基纳米复合材料具有优异的电子结构和光电化学性能。这使其不仅局限于光催化领域,更已经成为电化学催化领域的新宠。通过调控纳米结构,可以协同发挥复合材料性能激发电化学性能。以电化学储能及传感应用为目标,材料结构为切入点,深入分析并综述了石墨相氮化碳及其复合材料的材料设计方法、结构和性能,为进一步深化g-C_3N_4的科学化应用提供思路。     

银纳米粒子与氧化物纳米异质结构制备及应用

总结了近期银纳米粒子与氧化物纳米异质结构制备及应用研究进展情况,特别是银纳米粒子修饰的氧化钼纳米纤维异质结构、银纳米粒子修饰的钛酸盐纳米纤维异质结构、银纳米粒子@二氧化硅@银纳米粒子三明治异质结构的制备方法与性能表征.介绍了以上三种异质纳米复合结构的催化性能和银纳米粒子修饰的二氧化物纳米纤维异质结构的气体传感性能.     

钠硫电池电极结构改进与电池性能研究

研究了新型的钠硫电池钠极钠芯结构和硫极预制结构对电池性能影响．实验表明,钠极的钠芯结构不仅能改善电池放电性能,而且有利提高电池的比能量和安全性;内衬氧化铝纤维的硫极预制结构能缓和界面极化,改善电池充电性能．改进电极结构后的钠硫电池也有利于电池向商品化,实用性发展     

基于微观格点模型模拟PEMFC定向结构催化层

用微观格点模型对质子交换膜燃料电池(PEMFC)定向结构阴极性能进行了模拟,并与随机结构电极进行了对比,研究了催化剂利用率及电池性能的变化.计算了催化层内的传递和电化学反应,研究了质子、氧气及电化学反应速率在电极厚度方向上的分布,并且通过对比氧气浓度、离子电势和电化学反应速率的分布,证明了Pt/C颗粒在电极厚度方向上定向排布有利于提高电池性能.另外,研究了电极厚度对定向结构电极性能的影响,发现与随机结构电极不同,定向结构电极厚度越小,高电流密度下电极性能越好.     

稀土对Keggin结构磷钼酸催化剂结构和性能的影响

合成了具有Keggin结构的杂多酸催化剂。选用稀土元素La、Ce、Pr对催化剂进行掺杂,考察了添加稀土前后的结构、热性能以及对异丁酸的吸附情况,讨论了稀土的添加对催化剂结构和性能的影响。     

功能高分子型活性材料结构对钆离子选择电极性能的影响

本文采用接枝共聚方法合成功能高分子型钆化合物活性材料,研究了它们的结构和某些性能,结果表明这些活性材料的结构和性能对钆离子选择电极性能有较大的影响。     

石墨烯及其复合材料在锂离子电池中的应用

石墨烯是一种单原子层厚度的石墨材料,具有独特的二维结构和优异的电学、力学以及热学性能。同时它也是一种具有良好应用前景的锂离子电池电极材料。电极材料的微观结构对其性能有很大影响,利用石墨烯获得具有特殊形貌和微观结构的电极材料,能有效改善材料的各项电化学性能。本文综述了石墨烯及其复合材料在锂离子电池中的应用研究进展。在负极复合材料中,石墨烯不仅可以缓冲材料在充放电过程中的体积效应,还可以形成导电网络提升复合材料的导电性能,提高材料的倍率性能和循环寿命。通过优化复合材料的微观结构,例如夹层结构或石墨烯片层包覆结构,可进一步提高材料的电化学性能。在正极复合材料中,石墨烯形成的连续三维导电网络可有效提高复合材料的电子及离子传输能力。此外,相比于传统导电添加剂,石墨烯导电剂的优势在于能用较少的添加量,达到更加优异的电化学性能。最后对石墨烯复合材料的研究前景进行了展望。     

硒芳香杂环化合物的光谱和电化学性质

用紫外光谱，荧光光谱和循环伏安法研究了含硒芳香杂环化合物（苤硒脑）在不同溶剂中的谱学和电化学性质，对不同分子结构或取代基的苤硒脑化合物的性质进行了比较，并初步探讨了溶剂对苤硒脑化合物谱学性质的影响规律。     

The Infuence of Salicin on Rheological and Film-Forming Properties of Collagen

Collagen films are widely used as adhesives in medicine and cosmetology. However, its properties require modification. In this work, the influence of salicin on the properties of collagen solution and films was studied. Collagen was extracted from silver carp skin. The rheological properties of collagen solutions with and without salicin were characterized by steady shear tests. Thin collagen films were prepared by solvent evaporation. The structure of films was researched using infrared spectroscopy. The surface properties of films were investigated using Atomic Force Microscopy (AFM). Mechanical properties were measured as well. It was found that the addition of salicin modified the roughness of collagen films and their mechanical and rheological properties. The above-mentioned parameters are very important in potential applications of collagen films containing salicin.     

EP-g-PU IPN结构阻尼材料

采用-NCO封端的聚氧酯(PU)预聚物,制备了环氧树脂-聚氨酯互穿网络(EP-g-PU IPN);通过添加受阻酚四[β-(3,5-二叔丁基-4-羟基苯基)丙酸]季戊四醇(AO-60)制备了AO-60/EP-g-PU IPN.通过FT-IR、DMA、SEM分别研究了改性分子链的基团变化、改性体系的动态性能及断裂面的形态,...     

Ionogels of a Sugar Surfactant in Ionic Liquids

Green and environmentally friendly ionogels formed by a sugar surfactant were prepared in two kinds of imidazolium‐based ionic liquids. The phase transition from ribbon structures to lamellar structures induced by temperature and the transition mechanism were investigated in detail by means of freeze‐fracture TEM and field‐emission SEM observations, as well as small‐angle X‐ray scattering measurements. The rheological properties and tribological properties of two kinds of ionogels were systematically investigated. The difference in the lubricating properties and antiwear capability can be explained well by the mechanical and viscoelastic properties, as well as the different microstructures of samples destroyed by shear forces. This work provides a better understanding of the relationship between the structures, rheological properties, and tribological properties of ionogels.     

人造岩石固wx 包容锕系核素废物

研究了富钙钛锆石型和富烧绿石型两种人造岩石固化体包容锕系核素的配方设计和固化产品的鉴定评价,包括物理性能、抗浸出性能和耐辐照性能。采用了X射线衍射(XRD)、扫描电镜/能谱分析(SEM/EDS)和透射电镜/能谱分析(TEM/EDS)研究了矿相组合、元素分布和矿相化学组成等。研究表明,富钙钛锆石和富烧绿石型人造岩石都能很好地固化包容锕系核素废物。     

Properties and hydrolysis of PLGA and PLLA cross-linked with electron beam radiation

Radiation has been used as a processing tool to modify the properties of polymers. The aim of this study is to understand how electron beam radiation, together with pentaerythritol tetraacrylate (PTTA) as a tetra-functional monomer, can alter the properties (i.e. thermal and mechanical) and hydrolysis rates of PLGA and PLLA. The effects of radiation dose and PFM concentration on the physical properties of the polymers were investigated. The results showed that upon irradiation PLGA and PLLA cross-linked, and an increased in gel content was observed. Glass transition temperature (T_g) and mechanical properties of the polymers also increased. Cross-linked PLGA and PLLA samples were found to retard hydrolytic degradation. The mechanical properties of these polymers were also unaffected by hydrolysis. In summary, PLGA and PLLA cross-linked with PTTA were found to have enhanced mechanical properties and were able to retard hydrolytic degradation.     

复合载体TiO2-Al2O3的制备及其对Ni-Mo-S负载型催化剂加氢脱氧性能的影响

采用共沉淀法制备出复合载体TiO₂-Al₂O₃,用N₂-吸附、XRD和吡啶吸附红外光谱等手段进行表征。采用原位硫化法制备Ni-Mo-S/TiO₂-Al₂O₃负载型催化剂,以苯酚为模型化合物研究其加氢脱氧催化性能。主要研究铝源和沉淀剂对TiO₂-Al₂O₃复合载体性能的影响以及其作为载体对Ni-Mo-S/TiO₂-Al₂O₃催化苯酚加氢脱氧反应的影响。结果表明,以氯化铝为铝源制备的复合载体具有较大的孔容和孔径,孔容达1.12cm³/g,孔径达18.0nm;以硫酸铝为铝源和以碳酸氢铵为沉淀剂制备的复合载体具有较大的比表面积,高达295m²/g;氨水沉淀制备的复合载体具有较多的L酸;以硫酸铝为铝源制备的复合载体形成少量的B酸。TiO₂-Al₂O₃作为载体影响Ni-Mo-S/TiO₂-Al₂O₃负载型催化剂加氢脱氧性能的主要因素是载体的酸性和载体的比表面积。在300℃,4.0MPa条件下Ni-Mo-S/TiO₂-Al₂O₃催化苯酚的转化率达81.9%,产物中无氧化合物的总选择性达100%,脱氧率达79.4%。     

Effects of surface processing of lactose carrier particles on dry powder inhalation properties of salbutamol sulfate

The effects of the surface processing of lactose carrier particles on the dry powder inhalation properties of salbutamol sulfate were investigated. Lactose carrier particles were processed using a high-speed elliptical-rotor-type powder mixer (Theta-Composer). In the present study, drug/carrier powder mixtures were prepared, consisting of micronized salbutamol sulfate and coarse lactose carriers with various particle surface conditions prepared by surface processing. These powder mixtures were aerosolized by a Jethaler, and the in vitro inhalation properties of salbutamol sulfate were evaluated with a twin impinger. Compared with those of the powder mixed with unprocessed lactose carriers, the in vitro inhalation properties of the powder mixture prepared using the surface processed lactose carriers were significantly different, showing that the in vitro inhalation properties of salbutamol sulfate were improved. The in vitro inhalation properties increased with the rotor rotation rate. Using this surface processing system would thus be valuable for increasing the inhalation properties of dry powder inhalation with lactose carrier particles.     

热塑性淀粉/乙烯-乙烯醇共聚物复合材料的制备与性能

利用熔融共混的方法,制备得到热塑性淀粉/乙烯-乙烯醇共聚物（TPS/EVOH）复合材料,并对该复合体系的加工性能、机械性能、动态力学性能、流变性能以及吸水性进行了研究.结果表明：随着EVOH含量增加,复合材料中分子间作用力加强;复合体系的机械性能得到改善;当EVOH含量到达30%后,复合材料的吸水性明显降低.     

Effect of surface layering time of lactose carrier particles on dry powder inhalation properties of salbutamol sulfate

The effect of the surface layering time of lactose carrier particles on the dry powder inhalation properties of salbutamol sulfate was investigated. Lactose carrier particles were layered with vegetable magnesium stearate by physical mixing. In the present study, drug/carrier powder mixtures were designed consisting of micronized salbutamol sulfate and lactose carriers with various particle surface conditions prepared by surface layering. These powder mixtures were aerosolized by a Jethaler, and the in vitro deposition properties of salbutamol sulfate were evaluated by a twin impinger. Compared with the powder mixed with unlayered lactose carrier, the in vitro inhalation properties of the powder mixture prepared using the surface layering lactose carrier were significantly different, showing that the in vitro inhalation properties of the drug/carrier powder mixtures were improved. In vitro deposition properties (RP) increased with surface layering time. Using this surface layering system would thus be valuable for increasing the inhalation properties of dry powder inhalation.