聚醚硅油表面迁移行为对聚苯乙烯表面极性的影响

利用变角衰减全反射傅立叶变换红外光谱(ATR-FTIR)法和接触角,分析了聚醚硅油在聚苯乙烯共混物薄膜表面的选择性富集行为及对其表面结构和表面极性的影响,认为接触介质的表面性质是影响共混物中各组分产生选择性迁移扩散的重要影响因素.强极性介质的诱导作用可以在共混物表面层中产生剧烈变化的浓度梯度,而弱极性介质所产生的表面浓度梯度比较缓和.     

氨基改性聚醚硅油的合成、结构表征及应用

在Pt催化剂的作用下，利用含氢硅油与烯丙基缩水甘油醚、烯丙基聚氧乙烯聚氧丙烯醚的硅氢化加成反应合成聚醚／环氧硅油中间体，然后分别用吗啉、乙二胺、N,N-二甲基丙二胺、N-氨乙基哌嗪等氨解开环，制得了一系列氨烃基改性聚醚硅油AMPES，对其进行了结构表征和应用。结果表明：增加含氢硅油的数均分子量，提高硅含量，可改善AMPES的柔软性，而对织物的吸湿性影响不大。     

高效有机硅消泡剂的研制与应用

以二甲基硅油、疏水气相二氧化硅制成的硅膏和聚醚改性硅油为主要成份,Span-60、Twen-60为乳化剂,采用高速剪切乳化搅拌方式将水相在油相中进行乳化,制备出高效乳液型有机硅消泡剂。研究了各主要成分的含量及乳化温度对消泡剂性能的影响,得到的最佳配方为:硅膏的质量分数分别为12%,聚醚改性硅油4%,HLB值为9.5的复配乳化剂6%。制备的有机硅消泡剂的稳定性及消泡抑泡性能较好,适用范围广。     

聚醚改性硅氧烷的合成

利用低含氢硅油与端烯丙基聚氧烯醚进行硅氢加成反应合成了不含活泼氢的聚醚改性硅氧烷(1),羟值52.5 mgKOH·g-1,其结构经IR表征.由正交试验得到合成1的较佳反应条件为:n(Si-H):n(C=C)=1.0:1.1,催化剂H2PtCl6 20 mg·kg-1,于110℃反应3,5 h.     

硅氧烷表面改性聚醚酯聚酰亚胺的研究

通过两种方法。即将γ-氨丙基封端的聚二甲基硅氧烷和对氨基苯甲酸酯封端的聚(四亚甲基)醚与均苯四甲酸二酐共缩聚,和将两种预制的聚酰胺酸溶液共混,合成了一组硅氧烷改性的聚醚酯聚酰亚胺材料。ESCA能谱和表面水接触角测量研究材料的表面性质发现,硅氧烷在材料表面富集,对聚醚酯聚酰亚胺材料具有显著的表面改性作用,硅氧烷改性的聚醚酯聚酰亚胺,其热稳定性能和气体透过性能有一定程度的提高,但抗张强度和介电性能有所降低。     

负载生物活性功能基聚醚氨酯的表面自由能与表面血液相容性研究

水相接触角;负载生物活性功能基聚醚氨酯的表面自由能与表面血液相容性研究     

氨基改性聚醚型聚硅氧烷的制备及其柔软性能研究

用含氢硅油、烯丙基缩水甘油醚、烯基聚醚的硅氢化加成产物-聚醚/环氧硅油与胺反应制得了氨基改性聚醚型聚硅氧烷（APEPS）,对其结构与性能进行了表征和研究。结果表明,含氢硅油分子量、有机胺结构、氨基改性聚醚型聚硅氧烷的硅含量对APEPS性能有影响。提高硅含量、增加氨值,可改善APEPS的柔软性与滑爽感,但对织物的吸湿性影响不大。     

聚苯乙烯-g-聚乙二醇的制备及其表面改性作用

通过沉淀聚合方法,利用自由基共聚制备了苯乙烯-顺丁烯二酸酐共聚物(SMA),利用SOCl2的酰氯反应,在SMA大分子链上接枝聚乙二醇侧链,制备了聚苯乙烯-g-聚乙二醇(PEG-g-PS)的大分子表面改性剂。利用大分子表面改性剂在聚苯乙烯基体中具有选择性迁移扩散的特性,实现了对聚苯乙烯薄膜表面极性的改善作用。采用衰减全反射傅立叶变换红外光谱仪和表面静态接触角法检测了聚苯乙烯的表面极性。结果发现,PEG-g-PS上的聚醚链段可以有效的富集在聚合物表面,明显改善PS的表面极性和亲水性,表面极性可提高3倍,达到11.6mN/m。同时,大分子表面改性剂和聚苯乙烯基体间有一定的相容性,有效地克服了小分子表面改性剂容易流失,改性寿命较短的重要缺陷,使表面改性的持久性充分增加,实现对聚合物表面改性效果终生化的目的。而且大分子表面改性剂在极性溶剂的诱导作用下,可以实现进一步的迁移扩散,充分提高了聚苯乙烯的表面极性。     

N-[3-聚醚-3-(二甲氨基)-丙基]全氟辛基磺酰胺的合成及表面性能

阳离子氟碳表面活性剂;聚醚类;季铵盐型;临界胶束浓度     

聚醚接枝聚硅氧烷共聚物改进环氧树脂表面性能的研究

共混改性;形态;聚醚接枝聚硅氧烷共聚物改进环氧树脂表面性能的研究     

Different Distributions of Counterions in the Surface Layer of Cationic Surfactant Solutions

We have separately determined the surface tension of pure aqueous solutions of cetyltrimethylammonium chloride and cetyltrimethylammonium bromide and their surface potentials by a Kelvin probe system. With the help of Gibbs equation, the surface excess has been determined through approximating the chemical activity of the surfactant by their dilute bulk concentration. In the following, the surface potential—surface excess isotherms were established. Those potential isotherms evidence that cetyltrimethylammonium chloride solution has a higher value compared to that of cetyltrimethylammonium bromide under equal surface excess. This phenomenon is supposed to be owed to the different distributions of chloride and bromide ions within the adsorption layer of the solutions, which can be attributed to the different properties of those two anions.     

Preparation of ZnO Film on 2024Al Surface for Hydrophobicity Investigation

A uniform ZnO film with microscale rod-like structure has been obtained on 2024Al surface by the hydrothermal method and perfluorooctanoicacid has been used to enhance the surface hydrophobic performance of the ZnO film. The as-prepared ZnO film was characterized by scan electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectrum (XPS). The results indicate that the ZnO film is uniform and the ZnO microrods are 2 um in length. The water contact angle of hydrophobic surface is 146° and the sliding angle is 10°.     

分子自组装法制备具有可控浸润性的铜表面简

通过简单浸泡的方法在铜基底上制备出了具有微纳米复合结构的氧化铜,再利用混合硫醇溶液[含HS(CH2)9CH3和 HS(CH2)11OH]对浸泡后的表面进行修饰,通过控制溶液中HS(CH2)11OH的浓度,制备出一系列具有不同浸润性的铜表面,实现表面从超疏水到超亲水的有效调控. 研究发现,表面浸润的可控性源于表面复合结构与不同化学组成的协同作用,微纳米复合结构的存在为表面浸润性的调节提供了必要的条件.     

锂硫电池正极材料研究进展

电动汽车行业的迅速发展,逐步提高了对二次电池容量的要求,因此急需发展新型高容量锂电池。锂硫电池具有高理论比容量(1675mAh/g)和高理论比能量(2600Wh/kg),使其能够实现锂离子电池3~5倍的能量密度。但是,正极长链多硫化物溶解引起的容量衰减快、循环寿命短等因素限制了锂硫电池的实用化进程。本文针对正极聚硫锂溶解问题,从正极材料表面包覆、表面吸附、表面催化的角度对近年来提高锂硫电池循环性能的正极材料研究思路和研究进展进行综述,最后对提高锂硫电池性能的发展趋势提出展望。     

富锂锰基正极材料的表面改性研究进展

随着电动汽车和储能电站等电力设备的快速发展,对高能量密度的锂离子电池的需求日益增加.高比容量（>250 mAh·g^-1）的富锂锰基正极材料,有望成为锂离子电池实现高比能量（>350 Wh·kg^-1）的关键正极材料.富锂锰基正极材料的Li₂MnO₃相和晶格氧参与电化学反应使其拥有了高容量,但这也导致表面结构和成分容易发生变化,进而造成富锂锰基正极材料存在着诸如首次库伦效率低、倍率性能差和循环后电压和容量衰减严重等问题.因此,本文综述了富锂锰基正极材料的表面包覆、表面掺杂和表面化学处理三种表面改性方法,并进一步讨论了三种表面改性方法对材料性能提升的机制机理和优缺点.在此基础上,介绍了近些年基于多方法的表面联合改性工作.通过对富锂锰基正极材料进行表面联合改性,不仅可以改善其结构稳定性和抑制电极/电解液界面副反应,而且可以缓解其在循环过程中不断发生的结构转变和晶格氧的析出问题.最后,对富锂锰基正极材料表面改性研究方向进行了总结和展望.     

Surface viscoelasticity of phospholipid monolayers at the air/water interface

The surface viscoelastic properties of monolayers of two phospholipids DPPC (L--dipalmitoylphosphatidylcholine) and DMPE (L--dimyristoylphosphatidyl-ethanolamin), at the air-water interface have been investigated. Two techniques were used for the investigation. One involved use of an interfacial shear rheometer (torsion pendulum apparatus ISR1), to provide measurements of the shear viscosity _s as a function of surface pressure, and the second, a modified LB trough with an oscillating barrier to generate periodie dilation and compression so as to measure the dilational elastic modulusE as a function of surface area.Results indicate a strong dependence of _s andE upon monolayer phases. This suggests that the viscoelastic relaxation of monolayers can be understood as molecular rearrangements, domain exchange and molecular reorientations between different monolayer states.     

MgO缺陷和不规则表面的能带结构研究

用扩展休克尔紧束缚（ＥＨＴ）晶体轨道方法对ＭｇＯ表面缺陷和不规则结构进行能带计算,并对能带的结构及组成进行了讨论。计算结果表明,各种缺陷及不规则表面的表面状态与完整晶面比较,存在明显差异,前者由于其导带底部能带的变化造成导带和价带间的能隙减小。我们发现,ＭｇＯ缺陷及不规则表面吸附能力与其表面能大小及表面不同位置原子的净电荷数密切相关。缺陷模型的表面能均大于完整晶面,故缺陷有利于表面吸附     

分子自组装法制备具有可控浸润性的铜表面

通过简单浸泡的方法在铜基底上制备出了具有微纳米复合结构的氧化铜, 再利用混合硫醇溶液[含HS(CH₂)₉CH₃和 HS(CH₂)₁₁OH]对浸泡后的表面进行修饰, 通过控制溶液中HS(CH₂)₁₁OH的浓度, 制备出一系列具有不同浸润性的铜表面, 实现表面从超疏水到超亲水的有效调控. 研究发现, 表面浸润的可控性源于表面复合结构与不同化学组成的协同作用, 微纳米复合结构的存在为表面浸润性的调节提供了必要的条件.     

First‐principles study of the (001) surface of cubic PbTiO3

We present first‐principles calculations on the (001) surfaces of cubic PbTiO₃ with PbO and TiO₂ terminations. The cleavage energy, surface energy, surface grand potential, surface relaxation and surface electronic structure have been investigated by using the projector‐augmented wave method under generalized gradient approximation (GGA). The results show that surface energy of a TiO₂‐terminated surface is a little lower than that of a PbO‐terminated one, thus allowing both terminations to coexist. The PbO‐termination is stable in O‐ and Pb‐rich environments, while on the contrary, the TiO₂‐termination is stable in O‐ and Pb‐poor conditions. In addition, the surface rumpling S of a PbO‐terminated surface is slightly larger than that of a TiO₂‐terminated one. The relaxations dominantly take place on the outermost three layers, and an oscillatory (? + ?) damping (|Δd₁₂ | > | Δd₂₃ | > | Δd₃₄|) relaxation phenomenon appears for both terminations. The band gaps of both PbO‐ and TiO₂‐terminations are slightly lower than that of the bulk. Moreover, the DOS curves of each layer show that for the TiO₂‐termination, the top of the valence band of the first and third TiO₂ layers moves toward Fermi level. Copyright © 2008 John Wiley & Sons, Ltd.     

Bisquare robust polynomial fitting method for dimple distortion minimization in surface quality analysis

In this paper, the bisquare robust polynomial fitting (BSRPF) method for surface texture features assessment was proposed. Plateau-honed cylinder liner bronze surfaces with additionally burnished microcavities (defined as dimple, holes, and/or cavities) were taken into consideration. Analyzed details were measured with stylus (Talyscan 150) or white light interferometer (Talysurf CCI Lite) methods. It was assumed that application of commonly used (in surface contact and noncontact measurement technology) polynomial fitting procedures did not allow to extract required features; distortion of microreservoir dimples for oil consumption assessment was falsely estimated when valleys were near edge or on the edge located. Application of bisquare robust polynomial fitting method caused a minimization of microflattens of dimples irrespective of valley distribution; the biggest degree of polynomial fitting method applied, the minimal distortions of oil reservoirs were noticed. The valley size (depth and width) and valley-to-valley distance were also taken into account.