聚合物电流变体

本文概述了电流变体的发展概况，电流变机理、电流变效应的影响因素及聚合物电流变体的研究现状，并介绍了电流变化的组成春在机械制造、自动控制等领域的应用前景。     

甲壳素-壳聚糖对皂土悬浮液的絮凝

研究了三种摩尔质量大体相同而脱乙酰度分别为93%、78%和62%的甲壳素-壳聚糖在pH=3～6范围内对皂土悬浮液的絮凝性质, 并与非离子型絮凝剂聚丙烯酰胺作了比较, 证明含自由氨基的甲壳素-壳聚糖在酸性溶液中形成阳离子聚电解质后. 对带负电的皂土悬浮颗粒有很好的絮凝能力. 通过对上述三种聚合物的絮凝能力、在皂土颗粒表面的吸附量等测定, 认为絮凝中桥连机制起了主导作用, 但聚合物所带正电荷则有利于被皂土颗粒所吸附, 电中和还降低了颗粒间的静电排斥, 这都对桥连絮凝起了促进作用. 聚丙烯酰胺分子在水中不带电, 故当介质pH升高使皂土颗粒双电层变厚时, 絮凝能力迅速下降.     

聚苯胺导电复合物二次掺杂的基材效应

对十二烷基苯磺酸掺杂的聚苯胺与氯磺化聚乙烯或苯乙烯－丁二烯－苯乙烯三嵌段共聚物形成的复合物的二次掺杂进行了研究。二次掺杂的复合膜经反掺杂后的ＵＶ－Ｖｉｓ吸收光谱在５８０￣８００ｎｍ处呈现宽的吸收，证实了二次掺杂后ＰＡｎ主链的展开，同时表明ＰＡｎ在ＣＳＰＥ中的展开较在ＳＢＳ中更充分，ＥＳＲ动态测试表明二次掺杂诱导主链的载流子间相互作用有２种方式；ＰＡｎ／ＣＳＰＥ中的单极化子转变为双极化子；ＰＡｎ／Ｓ     

壳聚糖微囊的部分特性研究

以壳聚糖为主要材料,制备壳聚糖微囊。微囊直径在０．５－０．８ｍｍ间,微囊在ｐＨ４－１１的缓冲液中稳定,能耐受３０００ｒ／ｍｉｎ离心３０ｍｉｎ以上。用牛血清白和蛋白γ－球蛋白测其通透性,表明随着微囊所在溶液ｐＨ的升高,微囊通透性降低。壳聚糖的分子量在一定范围内对微囊通透性几乎无影响而脱乙酰度对通透笥影响很大。     

ELECTRORHEOLOGICAL PROPERTIES OF TALC POWDER/SILICONE OIL SUSPENSIONS UNDER DC FIELDS

In this study, the electrorheological （ER） behavior of suspensions prepared from d50 = 2.4 lam talc powder, dispersed in insulating silicone oil （SO） medium was investigated. Sedimentation stabilities of suspensions （c = 5 wt%） prepared using these talc powder powders were determined to be 78 days. The ER activity of all the suspensions was observed to increase with increasing electric field strength, concentration and decreasing shear rate. The shear stress of talc powder suspensions increased linearly with increasing concentrations of the particles and with the applied electric field strength. Electric field viscosity of all the suspensions decreased sharply with increasing shear rate and showed a typical shear thinning non-Newtonian visco-elastic behavior. Effects of frequency on the ER activity of talc powder/SO system were also investigated.     

稀土PMMA包裹硅铝氧烷凝胶的电流变效应

用聚甲基丙烯酸甲酯（PMMA）对由水玻璃,硝酸铝和α－甲基丙烯酸形成的硅铝氧烷溶胶进行包裹,得到PMMA包裹的硅铝氧烷凝胶,同时在反应过程中用稀土离子进行掺杂,得到的稀土掺杂PMMA微囊粉末加入到甲基硅油中得到稳定的悬浮液,加载电场后发现其电流变效应显著提高,在一定浓度下与未掺杂体系相比即时粘度从95Pa.s提高到178Pas.s。     

壳聚糖硫酸酯稀溶液的粘度特性

通过毛细管粘度法考察了壳聚糖硫酸酯(Sulfated Chitosan,SCM)稀溶液的粘度特性。在非电解质溶液中,SCM比浓粘度随浓度的变化符合Fouss-Strauss经验关系式:ηsp/C=316.45×(1+79.88C1/2)-1。通过外加强电解质,SCM表现出正常的粘度行为,并且[η]随着外加强电解质离子强度的增加而减小。     

壳聚糖的结构特性及其衍生物的应用

壳聚糖由甲壳素经脱乙酰基而得,又称为可溶性甲壳素。壳聚糖的结构特征使其具有了独特的物理化学性质和生物活性。本文介绍了壳聚糖的结构特性、重要的化学性质及衍生物的应用。     

十一种壳聚糖衍生物的紫外吸收特性

十一种壳聚糖衍生物的紫外吸收特性;壳聚糖;胆甾液晶;紫外光吸收剂;化妆品     

带相反电荷胶体颗粒混和悬浮体的流变学性能

研究了带相反电荷的粘土颗粒和MMH(铝、镁混合金属氢氧化物)颗粒形成的混和悬浮体的流变学性能,考察了盐对混合体系流变学性能的影响.结果表明,当粘土质量分数为1%时,悬浮体为牛顿型流体;当质量分数升至2%时,悬浮体表现出固体的弹性响应;特定粘土含量的悬浮体中,随着MMH量的增加,混合体系的屈服值和弹性模量亦增加,表明凝胶结构增强.向混合体系中加入NaCl,弹性模量、屈服值和粘度等流变参数均降低.与单组分粘土悬浮体或MMH悬浮体相比,双组分混合体系的结构恢复很快.     

壳聚糖氧化自组装膜的制备及其性能

由高碘酸钠和壳聚糖溶液反应,成功制备出壳聚糖氧化自组装膜。采用傅立叶变换红外光谱(FTIR)和X射线衍射法对氧化自组装膜进行了结构表征,并对膜的吸水率及其力学性能进行了测试。当壳聚糖为3 g,而高碘酸钠加入量等于0.010 g时,得到壳聚糖氧化自组装膜的最佳的抗张强度,干膜为54.32 MPa,湿膜为29.11 MPa,相对壳聚糖膜分别提高了17.52%和26.78%;并且得到了最佳的阻水性,其吸水率为78.51%,相对于壳聚糖膜降低了6.88%。     

甲壳素/甲壳胺的聚集态结构及性能

制备了不同脱乙酰度的甲壳素,并对脱酰化反应进行了研究,找出了适合不同脱酰度甲壳素的溶剂,探讨了制样温度与甲壳胺膜的结晶形态和力学性能之间的关系,比较了甲壳素、甲壳胺及不同来源甲壳素的结晶形态.     

纤维素/壳聚糖共混透明膜的制备及阻隔抗菌性能研究

利用壳聚糖溶液包覆法制备了具有高气体阻隔性及抗菌性的透明纤维素膜,其扫描电镜照片证明壳聚糖厚度在1.31 ～4.07 μm之间.通过红外光谱、紫外光谱、热重分析仪、电子万能试验机和接触角测试仪对纤维素/壳聚糖共混膜的结构和性能进行了详细研究,结果表明由于壳聚糖和纤维素之间具有一定的氢键相互作用,使得纤维素/壳聚糖共混膜较好地保持了纯纤维素膜的机械强度,其拉伸强度都大于110 MPa.此外,壳聚糖的包覆对纤维素膜的透明性没有影响,它在600 ～ 800 nm处的透光率仍维持在80％左右,并且提高了纤维素膜的疏水性,其水接触角从纤维素膜的70°提高到了100°.利用气体渗透仪进一步研究了纤维素/壳聚糖共混膜的氧气阻隔性,结果表明该膜具有很好的氧气阻隔性,其氧气渗透系数甚至低于市场上理想的氧气阻隔材料乙烯-乙烯醇共聚物(EVA).金黄色葡萄球菌抗菌测试表明,通过壳聚糖包覆法改性纤维素能够明显提高纤维素膜的抗菌性.     

Study of Shear Properties of Nanoparticle Suspensions

Low-frequency complex shear modulus of the colloidal suspensions of nanoparticles Nd:YAG in ethylene glycol was measured for the first time by using acoustic a resonance method with piezoquartz vibrator. Dependence of viscoelastic properties of the colloidal suspensions on nanoparticles sizes and their concentrations has been carried out.     

纳米3Y-TZP水悬浮液性质研究

采用2-膦酸丁烷-1,2,4-三羧酸(PBTCA)为分散剂,制备了稳定的纳米3Y-TZP(氧化钇稳定氧化锆)粉体悬浮液.运用ζ电位及流变学等方法表征了分散剂对浆料性质的影响.采用静电排斥稳定理论对颗粒间的相互作用进行模拟,所得结果与实验吻合得很好.讨论了该分散剂对悬浮液的稳定机理.     

Magneto-Optical Properties of Silica Gel Containing Magnetite Fine Particles

The magnetic composite materials that consist of transparent matrix and magnetic fine particles are expected to have large residual magnetization and coercive force because of their fine magnetic domain structure, and also to show magneto-optical effects. Silica gels containing magnetite (Fe₃O₄) fine particles were prepared by sol-gel method. The magnetic, optical and magneto-optical properties of the composites were investigated by measurements of magnetization curves, UV-visible spectra and Faraday rotation in visible range. The saturation magnetization of the composite was almost as same as that expected from the amount of magnetite fine particles in it. Although the composites had large and broad absorption at around 400 nm, they still maintained their transparency. The origins of decrement of transparency attributed to the optical absorption of magnetite and scattering due to magnetite fine particles. The whole composites showed positive Faraday rotation under external static magnetic field due to the large contribution of diamagnetic silica gel matrix. Magnetite contributed negative Faraday rotation with maximum at around 470–480 nm to the magneto-optical spectra of the composites.     

CS-PMA30水凝胶对考马斯亮蓝控释性能的研究

壳聚糖(CS)是自然界中唯一的聚阳离子碱性多糖,具有良好的组织相容性、生物可降解性、无毒、无刺激、pH响应性等优点,因而在药物控释领域的具有潜在的应用价值。将聚阳离子壳聚糖与聚阴离子甲基丙烯酰氧乙基磷酰胆碱-甲基丙烯酸二元共聚物(poly(MPC-co-MA),PMA30)进行静电复合,制备CS-PMA30聚离子水凝胶。以考马斯亮蓝为模型药物,对CS-PMA30水凝胶的控释性能进行研究。结果表明,该CS-PMA30体系是通过静电作用形成的物理交联水凝胶,具有pH响应性,有望在药物控释、组织工程等领域得到广泛应用。     

Solution Properties of Mixed Starch/Chitosan Revealed by Resonance Light Scattering

The association behavior of starch and chitosan and the dilute solution properties of the starch/chitosan complex were investigated by means of resonance light scattering(RLS) spectra. The interaction between starch and chiotsan was proved by RLS. Based on the results, the appropriate association condition was selected. However, the solution property of starch/chitosan was affected greatly by external factors such as pH value and metal ionic strength. The change of pH, which causes the irreversible transition of solution from transparent into murky, provides some important information of partitioning behavior of the complex in solution. The durative enhancement of RLS intensity for the complex exhibited two inflexions and a plateau in the presence of a certain amount of Fe³⁺. It indicates that Fe³⁺ not only increases the RLS intensity, but also induces the micell-aggregate transition of the complex in solution. Moreover, the thermodynamic parameters for micell formation process at different temperatures, based on the RLS values, were calculated.     

聚苯胺粒子悬浮液的电流变特性

将聚苯胺作为分散粒子，电绝缘油 分散介质组成电流变流体，研究了电场强度，温度等因素与ＥＲＦ的静态屈服应力和电流密度的关系。结果表明：τｓ和ｉ随电场强度的变化皆成指数关系。