阴阳离子聚氨酯/羟基磷灰石复合微球的制备及其自组装

分别以2,2-双羟基丙酸(DMPA)和N-甲基二乙醇胺(MDEA)作扩链剂,采用自乳化法成功制备出带有正、负电荷的阳、阴离子聚氨酯/羟基磷灰石(PU/HA)微球,并考察HA的复合比例对微球形貌、理化性能的影响。在此基础上,通过微球间的静电作用力,将制备出的阴、阳离子复合微球自组装形成凝胶体系,并对其力学性能进行探究。SEM、ζ电位和激光粒度结果显示成功制备出具有一定形貌的带电微球,其中当扩链剂含量为15%(n/n)、HA含量为10%(w/w)时,微球形貌较佳且粒度分布均匀;X射线衍射、热分析结果表明,微球确为一定比例的HA与PU复合产物;自组装体系的流变学测试结果表明,微球组装后的产物呈类凝胶状态,具有较高的弹性模量,并有一定的可注射性。同时,骨髓间充质干细胞(BMSCs)可在组装材料表面粘附、铺展,生长良好。     

羟基磷灰石/氧化锆复合涂层热稳定性和结合强度的研究

为了提高羟基磷灰石(hydroxyapatite，HA)涂层的结合强度，采用水热电沉积法在HA涂层中引入第二相颗粒氧化锆(ZrO₂)制备HA/ZrO₂复合涂层，研究了ZrO₂晶型对涂层表面形貌、相组成、热稳定性和涂层结合强度的影响。实验结果表明，ZrO₂的复合减小了HA晶体尺寸，但不影响HA水热电沉积的机理；1 200 ℃热处理后，HA分解生成的CaO和ZrO₂形成固溶体，使单斜晶型(m-ZrO₂)和四方晶型(t-ZrO₂)的ZrO₂转变为立方晶型的的ZrO₂(c-ZrO₂)，并促进HA的完全分解；HA/ZrO₂复合涂层的结合强度明显高于纯HA涂层的结合强度，且随涂层中ZrO₂含量增大和热处理温度的升高而增大。1 000 ℃热处理后，HA/ZrO₂复合涂层既有较高的结合强度，又可获得对骨生长有利的HA+β-Ca₃(PO₄)₂(β-TCP)双相结构。     

表面图案化磁性复合微球的原位制备与表征

采用反相悬浮聚合法合成了丙烯酸(AA)含量不同的N-异丙基丙烯酰胺-丙烯酸共聚物P(NIPAM-co-AA)微凝胶, 并以其作为微反应器, 通过原位外源沉积法制备了一系列微米级、表面具有图案化结构的SiO₂-Fe₃O₄-P(NIPAM-co-AA)磁性复合微球. 实验结果表明, 复合微球的表面结构与微凝胶的组成、Fe₃O₄和SiO₂的沉积量有关. 在微球表面进行修饰, 可得到表面带有氨基等官能基团的磁性复合材料. 将这种功能化磁性微球用于识别生物大分子并进一步用于生物医学领域具有重要的意义.     

碳纳米管复合微球修饰L-色氨酸及其对LDL的吸附性能

本文以多孔碳纳米管/活性炭复合微球为载体, 以L-色氨酸为配基, 采用环氧氯丙烷偶联法, 制得修饰L-色氨酸的碳纳米管/活性炭复合微球(L-CNTs/AC)。采用扫描电镜、氮气吸附、傅立叶红外光谱、热分析、X射线光电子能谱等对复合微球进行表征;通过体外静态吸附法对其低密度脂蛋白(LDL)吸附能力进行初步研究。结果表明:环氧氯丙烷偶联法可接枝上L-色氨酸。复合微球中碳纳米管加入量越多, 对LDL的吸附能力越强;当碳纳米管加入量为45wt%时, 对LDL的吸附量达4.623 mg·g^-1, 是未添加碳纳米管的2.3倍多。这是因为碳纳米管不仅可促进复合微球中20~100 nm孔的形成, 而且还可促进复合微球配基修饰量的增多, 从而大大增强了复合微球对LDL的吸附能力。此复合微球可望开发成一种新型的血液灌流LDL吸附剂。     

交联聚膦腈中空微球的可控制备

以分散聚合法制备的聚苯乙烯微球为模板,以六氯环三膦腈、4,4’-二羟基二苯砜为共聚单体,三乙胺为缚酸剂,室温条件下制备出了聚苯乙烯／聚膦腈（核／壳）复合微球,然后用四氢呋喃处理该复合微球,得到聚膦腈中空微球。利用红外光谱、元素分析、扫描电镜及投射电镜对所制备中空微球的结构及形貌进行了表征。结果表明,所制备聚膦腈中空微球...     

电诱导牙釉质表面羟基磷灰石涂层形成的研究

以含Ca(NO₃)₂、NH₄H₂PO₄和NaNO₃组成的溶液作为电解液,在人牙釉质表面电诱导制备了羟基磷灰石(HA)涂层。应用X射线衍射(XRD)﹑扫描电镜(SEM)和能谱分析(EDS)对形成涂层后的牙釉质样品进行分析和表征,研究了电解液初始pH值﹑电流密度和温度的变化对涂层的组成﹑结构和形貌的影响。研究结果表明这些因素对涂层的组分(HA)没有显著影响,而对涂层中HA晶体c轴的择优取向度的影响则较显著。当控制电解液的初始pH值为6﹑电流密度为0.5 mA·cm^-2﹑温度为55 ℃的时候,涂层中HA晶体沿c轴方向择优取向生长,且择优取向度和牙釉柱的HA较为接近。     

中空高分子荧光微球的制备及其免疫层析检测应用

以过硫酸钾（KPS）为引发剂,甲基丙烯酸缩水甘油酯（GMA）和苯乙烯（St）为单体,采用无皂乳液聚合法制备了表面官能团化的高分子微球。研究发现添加微量NaCl制备得到的高分子微球,经四氢呋喃（THF）溶胀处理后,能够得到单分散且表面完整的中空P （St-co-GMA）微球。随后使用有机溶胀的方式将Eu(Ⅲ)配合物染料负载于微球壳层中,实现了α1微球蛋白（α1-MG）和β2微球蛋白（β2-MG）的免疫层析检测。     

一元醇热法制备SrHfO3：Ce超微球发光粒子

以Sr(NO₃)₂和HfOCl₂·8H₂O为原料,乙醇/水作溶剂,KOH为矿化剂,Ce(NO₃)₃·6H₂O作为激活剂,用一元醇热法制备了掺杂Ce³⁺的SrHfO₃超微球粒子。用XRD、SEM、荧光光度计分析了粒子合成过程的物相变化、形貌特征及激发和发射光谱。结果表明：在n_Sr：n_Hf=1：1,V_C2H5OH：V_H2O=4：1,水热合成温度140℃,反应时间4h,pH=13.5的条件下,获得SrHfO₃：Ce形貌为球微、分散均匀的粒子,粒径约900nm。当Ce³⁺掺杂浓度为0.7mol%时发光强度最大。     

基于3D受限自组装构筑中空介孔氧化硅/碳复合微球

发展简单、高效、可控的方法来制备中空介孔微球是介孔材料领域的研究热点.本工作结合嵌段共聚物的三维受限自组装(3D-CSA)和自模板碳化策略,建立了一种构筑中空介孔微球的新方法 .首先,采用乳液-溶剂挥发法实现嵌段共聚物与全氟辛烷(PFO)在3D受限空间的分级组装,获得了核-壳结构微球,其中壳层由微相分离的嵌段共聚物构成.然后,在壳层的连续相选择性地复合氧化硅,既实现了无机框架的负载,又实现了对连续相聚合物链选择性交联.对复合微球进行煅烧处理后,实现了壳层连续相聚合物的选择性碳化,获得了中空介孔氧化硅/碳复合微球.本研究系统地阐述了核-壳型分级结构微球的形成机理和必备条件,研究了氧化硅前驱体添加量和嵌段共聚物分子量对中空介孔氧化硅/碳复合微球形貌的影响,为制备中空介孔微球材料提供了一种简便、可控的方法.     

Ag掺杂型空心TiO2纳米微球的制备与表征及其光催化性能

通过甲基丙烯酸与苯乙烯的乳液聚合制备了表面载有阴离子的聚苯乙烯(PSt)纳米乳胶粒. 在乙醇与水的混合溶剂中, 用硅烷偶联剂乙烯基三甲氧基硅烷对其进行表面改性. 以此乳胶粒为模板, 加入钛酸四丁酯和硝酸银制备了Ag₂O掺杂型聚苯乙烯/二氧化钛(PSt/TiO₂)复合微球. 对该微球在180 °C进行液相预处理、干燥、500 °C煅烧等步骤制备了Ag 掺杂型Ag-TiO₂复合粒子. 通过扫描电镜(SEM)、透射电镜(TEM)和X射线衍射(XRD)等手段对PSt/TiO₂复合粒子及Ag-TiO₂空心粒子的形貌及晶体结构等进行了表征. 考察了Ag-TiO₂复合粒子在紫外光(365 nm)与紫外-可见光(370-760 nm)下对罗丹明B (RhB)降解的催化活性. 结果表明, 与不含银的TiO₂空心微球相比, 在紫外光照射下, 银含量(n_Ag/n_Ti)为0.1%的Ag-TiO₂复合粒子对RhB的降解率提高了11%左右; 在紫外-可见光照射下, n_Ag/n_Ti为1.0%和2.0% 的Ag-TiO₂复合粒子对RhB的降解率提高了30%左右.     

聚氨酯与铁电陶瓷粉复合物的电致感应性能研究

利用双辊制备了一系列热塑性弹性体聚氨酯（PU）和铁电钛酸锆酸铅盐（PZT）的电感应PZT／PU复合物。X－衍射和SE镜结果显示,复合物中,在铁电相中PZT陶瓷粉呈现结晶态并且均匀分布在PU基体中,复合物的弹性模量和相对电容率随着复合物中PZT体积分数增加而升高,在高压电场下,低PZT含量的复合物呈现负的电致伸缩应力,当PZT体积分数增加到6％以上时,在某个临界电场下,复合物呈现出电致伸缩应力反转的特性,即电致伸缩应力从负转变为正,并且发生应力反转的临界电场随着复合物中PZT体积分数的增加而降低,PU的电致伸缩特性与PZT在高电场下极化反转效应结合,导致了PZT／PU复合物这种有趣的性能,因此PZT／PU复合物将在高电压场方面作为传感器开关材料得到广泛应用。     

聚醚聚氨酯/环氧树脂互穿网络高聚物的研究(Ⅰ)

互穿网络高聚物(IPN)是两种或多种交联聚合物的共混体。由于两种聚合物网络相互贯穿和缠结,链节间的永久锁结产生强迫互容,使不同聚合物达到最紧密混合,最大限度地控制多相体系的相分离,IPN材料显示不寻常的耐热,耐溶剂和高强度等特点,远远超过其聚合物本身的性能。在IPN中,两网络相互贯穿程度越高,相分离越低,这主要取决于构成聚合物本身的相容性和最终网络结合方式。本文通过改变组     

Preparation of P(MBA‐co‐MAA)/Zr(OH)4/P(EGDMA‐co‐MAA)/TiO2 Tetra‐layer Hybrid Microspheres and the Corresponding ZrO2/TiO2 Double‐shelled Hollow Microspheres

Double‐shelled zirconia/titania (ZrO₂/TiO₂) hollow microspheres were prepared by the selective removal of the polymer components via the calcination of the corresponding tetra‐layer poly(N,N′‐methylenebisacryl amide‐co‐methacrylic acid) (P(MBA‐co‐MAA))/Zr(OH)₄/poly(ethyleneglycol dimethacrylate‐co‐methacrylic acid) (P(EGDMA‐co‐MAA))/TiO₂ hybrid microspheres. These tetra‐layer microspheres were synthesized by the combination of the distillation copolymerization of N,N(‐methylenebisacryl amide‐co‐methacrylic acid (MBA) or ethyleneglycol dimethacrylate (EGDMA) crosslinker and methacrylic acid (MAA) for the preparation of polymer core and third‐layer as well as the controlled sol‐gel hydrolysis of inorganic precursors for the construction of zirconium hydroxide (Zr(OH)₄) and titania (TiO₂) layers. The thicknesses of zirconia and titania shell‐layers were conveniently controlled via varying the feed of zirconium n‐butoxide (Zr(OBu)₄) and titanium tetrabutoxide (TBOT) during the sol‐gel hydrolysis, while the sizes of polymer layers were tuned through a multi‐stage distillation precipitation copolymerization. The structure and morphology of the resultant microspheres were characterized by transmission electron microscopy (TEM), X‐ray diffractometer (XRD), X‐ray photoelectronic spectroscopy (XPS), and thermogrametric analysis (TGA).     

STRESS-INDUCED CRYSTALLIZATION OF POLYURETHANE/MONTMORILLONITE NANOCOMPOSITE

Exfoliated polyurethane/montmorillonite nanocomposites with both high elongation at break and high tensilestrength were studied by dynamic-infrared spectroscopy (dynamic-IR). The results show that crystallization induced byadditional stress is impeded by the nano-layered organo montmorillonite.     

Study of a new novel process for preparing and co-stretching PTFE membrane and its properties

A new idea regarding improvement of the elastic recovery property of a PTFE/PU compound membrane through a co-stretching process was put forward. The experimental results show that the PTFE/PU membrane has great elastic recovery owing to PU. When the longitudinally stretching ratio of PTFE is 200%, the traverse stretching ratio is 850%, and the thickness of PU is 0.03 mm. When the longitudinally and traverse elastic recovery of PTFE/PU is 82.1% and 88.6%, respectively, the porosity is 78.0%, mean pore size is 0.382 μm, and the water vapour permeability is 9330 g/24 h m². It has been used for the SARS protective clothing in China.     

Physico-mechanical and WAXS studies of PU/PS semi interpenetrating polymer networks

The polyethylene glycol (PEG) based polyurethane (PU) and its semi interpenetrating polymer networks (SIPNs) with polystyrene (PS) were prepared. The FTIR, physico-mechanical properties like density, tensile strength, percentage elongation at break and surface hardness of the IPNs were measured. Wide angle X-ray studies (WAXS) were made to know the microcrystalline parameters such as crystal size (〈N〉), lattice disorder (g), surface (D_s) and volume (D_v) weighted crystal size of SIPNs. The different asymmetric column length distribution functions were employed using Exponential, Lognormal and Reinhold methods and the results are compared.     

COMPATIBILITY OF PVC WITH POLYURETHANES OF DIFFERENT SOFT SEGMENTS

Blends of PVC and polyurethanes with four different soft segments of molecular weight 1000 were prepared and studied by dynamic mechanical and DSC techniques. It was found that the compatibility of PVC with segmented polyurethanes was related to the mixing of PVC molecules and the soft segments of the polyurethanes. Polyester based polyurethanes are more compatible with PVC than polyether based polyurethanes. Solution cast blends of PVC with PCL-polyurethane (1/2/1) exhibit single and narrow glass transition, while the blends with PPO-polyurethane (1/2/1) are completely incompatible. The compatibility was found to decrease with increasing hard segment content for all the polyurethanes used. The methods of blend preparation may change the compatibility of PVC/PU blends through their influence on the mixing or demixing of the hard and soft segments.     

Synthesis and Characterization of Polyurethane/Poly (Urethane Modified Bismaleimide-Bismaleimide) IPNs

Themethodofblendingbyinterpenetratingpolymernetworks(IPNs)isoftenusedtoobtainelastomerswithpropertiesinexcessofthoseexhibitedbytraditionalblendingways'.Inthispaper,aseriesofnovelpolyurethane/poly(urethanemodifiedbismaleimide-bismaleimide)(PU/P(UBMI-BMI))IPNsweresynthesizedandcharacterizedby'HNMR,FTIR,TEM,andTGAanaIysis.BMIwassynthesizedasfollowsfUBMlwasintroducedtomodifythecompatibilityofthetwonetworks,whichwassynthesizedasfollows:Where(l)ishydroxyl-terminatedpoly(diethyleneadipa…     

电纺丝法制备聚乳酸/多壁碳纳米管/羟基磷灰石杂化纳米纤维的研究

电纺丝是一种利用聚合物溶液或熔体在强电场中进行喷射纺丝的加工技术,所制得的纤维、直径一般在数十纳米至几微米之间,比传统方法制得的纤维直径小几个数量级,是获得纳米尺寸长纤维的有效方法之一．