理想吸附混合物在二位不均匀模型表面上的活度系数

对理想吸附混合物在二位不均匀模型表面上的表面活度系数进行了系统的计算.结果表明,表面不均匀性将导致理想吸附混合物表观地呈现与Raoult定律的负偏差(表面活度系数小于1).但在与固-液界面相似的情况,即总覆盖度接近于1的条件下,算得的表面活度系数-吸附相成分关系皆呈现几乎完全对称的形状.因此实验测得的表面活度系数-吸附相成分关系所呈现的不对称性,可能是不同分子之间非理想的相互作用所引起,而不是表面不均匀所造成的.     

Preparation of Encapsulated Polymer Adhesion Beads and Adhesion with Porous Fibers

Adhesion beads of 10–130 μm, prepared by suspension polymerization, were encapsulated by melamine–formaldehyde. The capsule-type adhesives prepared consist of core and shell structure where the core region is sticky and viscous and the shell region consists of a hard shell at room temperature. The air permeable pads are made by hot pressing the mixture of capsule-type adhesives and porous materials including charcoal chips and Camellia sinensis fibers, which have a porous structure. The interfacial adhesion between polymer adhesion bead and porous fibers after processing shows a good porous sheet structure, which can penetrate air.     

Methods to determine surface energies of natural fibres: a review

To tailor the interaction across composite interfaces especially for the development of green composites, i.e. composites made completely from renewable materials, information about the fibre surfaces is required. We review the current state of the art of methods to determine the surface tension of natural fibres and discuss the advantages and disadvantages of techniques used. Although numerous techniques have been employed to characterise surface tension of natural fibres, it seems that commonly used wetting techniques are very much more affected by the non-ideal character of natural fibres. Inverse Gas Chromatography (IGC) is a much better suited technique to determine the surface energetic properties of natural fibres than wetting techniques. The surface tension of natural reinforcements, determined using IGC, was reported for nanosized bacterial cellulose as well as bamboo, cornhusk, flax, hemp and sisal, covering a wide range of cellulose content. The effect of methods to separate/extract fibres from the plants as well as of a few surface modification procedures on the fibre surface properties is also reviewed. The dispersive part of the natural fibre surface tension γ ^d _S varies from 32 to 61 mJ/m². The fibre surface tension increases with increasing cellulose content of natural fibres. We also found that a higher basicity (Donor Number, K _B to Acceptor Number, K _Aratio) was observed for fibres containing more cellulose. This may be reflective of higher crystalline cellulose content in the surfaces of the fibres, as only the ether linkage of the cellulose is labile for hydrogen bonding.     

螺浆烷

本文综述了螺浆烷的最新进展,详细叙述了螺浆烷的合成、结构与性质,特别是小螺浆烷的张力能及桥头-桥头碳-碳单键的价键状态。     

固体表面能色散成分的测定

Tamai, Hamilton, Carre等曾通过测量烷烃-水双液参照体系在固体表面的接触角,采用基于界面非色散成份的均方关系, 计算了高表面能固体的表面能色散成份(γs^d)及非色散成份(γs^p), 对此计算方法, Fowkes曾给予批评, 提出界面能的非色散成份主要来源于酸碱配位作用, 基于非色散成份均方关系的计算不能正确反映实际情况, 本研究改进了由双液法接触角值计算γs^d值的方法。     

ω-氯代氧杂全氟羟酸及其与溴化辛基三甲铵混合体系的表面化学性质研究

对ω-氯代氧杂全氟羟酸(ClCF)与溴化辛基三甲铵(C8N)混合体系的表面活性和泡添性质进行了研究。溶液表面张力测定的结果表明, ClCF及其混合体系有很低的监界胶团浓度(cmc)和γcmc值, 即有很高的表面活性。ClCF溶液有很好的起泡性能, 但ClCF-C8N混合体系与一般正负高子表面活性剂混合体系迥异, 显示出ω-氯代结构的特殊影响。     

一种细菌糖脂的化学结构和物化性能

从土壤中分离得到一支假单孢菌, 当它生长在正烷烃或植物油中时分离得到两个具有表面活性的体外糖脂, 用柱层析及制备薄层层析得以纯化, 样品经负离子化学电离质谱、快原子轰击质谱以及^1H和^1^3C核磁共振谱鉴定其结构为鼠李糖脂1和2; 它们都具有降低表面张力、水与十六烷之间的界面张力, 以及良好的乳化性、发泡性及增溶性.     

Bredt规则和双环桥烯化合物

本文评述了Bredt规则和双烯化合物特征及合成发展。     

Stefan 公式

本文应用径向分布函数概念和物理界面界面层模型,对Stefan公式进行了理论讨论,以往报道Stefan系数分别为2,4,6,6,6.67.本文理论推导得到,对球状分子为5.333.理论计算与实验数据符合得较好。     

PVP与C~1~4BE之间的相互作用

通过表面张力和胶束聚集数的测定,研究了聚乙烯吡咯烷酮(PVP)与两性表面活性剂十四烷基甜菜碱(C~1~4BE)之间的相互作用。结果表明,PVP与C~1~4BE可通过其分子间的疏水作用和极性基团间的静电力形成PVP大分子/表面活性剂聚集体。因此,混合溶液的表面张力-浓度曲线表现出两个转折点,C~1~4BE的胶束聚集数随PVP浓度增大而减小。