有机-无机杂化纳米复合材料PMMA/TiO2的制备及性能研究

本文对聚甲基丙烯酸甲酯(PMMA)和纳米TiO2复合材料的制备工艺与光学性质进行了研究.利用XRD、SEM、红外光谱、紫外可见光谱、热重等对纳米颗粒及复合材料进行了表征.结果表明:TiO2纳米颗粒经偶联处理后结构没有明显变化,其红外特征峰均发生了红移,PMMA热分解温度随TiO2加入量增大而提高,PMMA/TiO2纳米复合材料在可见光区透过率随TiO2加入量增大而迅速降低.     

PMMA/TiO2纳米复合材料的性能研究

利用偶联剂钛酸正丁酯对纳米二氧化钛颗粒进行预处理, 而后通过原位聚合制备了表面包覆聚甲基丙烯酸甲酯的纳米二氧化钛粉体. 通过红外光谱(FI-IR)、热重分析(TG)、差热扫描(DSC)、X射线衍射(XRD)、透射电镜(TEM)和扫描电镜(SEM)等研究了PMMA/TiO2有机-无机纳米复合材料的结构和性能.结果表明,PMMA包覆在TiO2的表面,包覆率为38.44%;PMMA/ TiO2纳米复合材料的起始分解温度和玻璃化温度分别为337 ℃和138 ℃,平均粒径为22.7 nm.表面改性后的纳米二氧化钛颗粒在有机溶剂中具有良好的分散稳定性能,同时确定了原位聚合PMMA/TiO2的最佳工艺条件为改性剂的用量15.8%,超声聚合反应时间1.5 h,反应温度为80 ℃.     

纳米TiO2的表面处理对PET/TiO2复合材料流变特性的影响

采用表面接枝改性的方法对纳米TiO2进行表面修饰,通过熔融共混制得PET/TiO2纳米复合材料,研究了不同表面特性的PET/TiO2复合材料的流变特性。结果表明:加入纳米TiO2的PET体系粘度降低,经表面接枝偶联剂γ-缩水甘油醚氧丙基三甲基硅烷(GPS)或聚甲基丙烯酸甲酯(PMMA)的TiO2对PET粘度的降低程度减弱,当纳米TiO2质量分数大于3%时,粘度趋于稳定。PET/PMMA-TiO2复合体系的粘流活化能最大,温度敏感性强。     

TiO2纳米粒子对PVDF超滤膜的结构与性能影响研究

采用溶胶-凝胶法制备了不同纳米TiO2溶胶含量的TiO2/PVDF超滤膜,探讨TiO2溶胶及其含量对膜性能及结构的影响,并利用X射线衍射、扫描电子显微镜、红外光谱和接触角测量仪表征了复合膜的结构.结果表明,经纳米TiO2溶胶改性后,TiO2/PVDF复合膜的孔隙率、接触角和结构等都发生了显著的变化,在TiO2溶胶添加质量分数为4％时条件下,膜的孔隙率为74.5％,水通量为430.6L·m-2·h-1,截留率为82.5％.     

高性能纳米TiO2／HIPS复合材料的研制

采用溶胶－凝胶法制备纳米TiO2,并对纳米TiO2进行表面处理,在大分子分散剂存在下,通过母料法工艺制备了纳米TiO2/HIPS复合材料。实验结果表明,制备的纳米TiO2/HIPS复合材料的缺口冲击强度、拉伸强度和弹性模量在纳米TiO2含量为2％时上升为最大值,且复合材料的硬度、耐热性能、阻燃性能随纳米TiO2含量的增加而提高。     

多孔PMMA/TiO2纳米复合材料的制备及其压缩力学性能

通过甲基丙烯酸甲酯本体聚合发泡的新方法,制备了多孔聚甲基丙烯酸甲酯(PMMA)/TiO2纳米复合材料,对所得复合材料的压缩力学性能进行研究。结果表明,复合材料的压缩应力-应变曲线具有多孔泡沫材料明显的线弹性段、塑性屈服平台段及致密段特征;随着纳米TiO2含量的增加,复合材料的压缩弹性模量和压缩强度也随之增大;而对于相同纳米TiO2含量的复合材料来说,随着变形速率的增大,材料的压缩强度随之增大。     

聚丙烯酸酯/ TiO2-SiO2纳米杂化材料的制备与性能研究

用原位复合、溶胶-凝胶法成功制得热固性聚丙烯酸酯基纳米SiO2包覆TiO2的有机-无机纳米杂化材料,通过红外光谱(FT-IR)、透射电镜(TEM)、扫描电镜(SEM)、紫外-可见光谱(UV-Vis)及热失重和差示扫描量热法(TG-DSC)等对材料的结构和性能进行了表征.实验证明了聚丙烯酸酯/TiO2-SiO2纳米杂化材料对紫外线有很好的屏蔽效果及更好的热稳定性.     

细乳液聚合法TiO_2/PMMA纳米复合粒子的制备及其性能

采用细乳液聚合法制备了二氧化钛/聚甲基丙烯酸甲酯(TiO2/PMMA)纳米复合粒子,研究了引发剂、助乳化剂、乳化剂、单体结构对TiO2/PMMA纳米复合粒子性能的影响。结果表明,十六烷(HD)比十二醇和十六醇更能有效抑制甲基丙烯酸甲酯(MMA)液滴在水相中的Ostwald熟化效应,当MMA占TiO2质量的60%,HD占单体质量的6%,可聚合乳化剂1-烯丙氧基-3-(4-壬基苯酚)-2-丙醇聚氧乙烯(10)醚硫酸铵(DNS-86)占整个体系质量的2%时,制备TiO2/PMMA纳米复合粒子分散体的粒径为185 nm,此时TiO2/PMMA纳米复合粒子与细乳液粒径差距较小;采用TiO2/PMMA纳米复合粒子制备喷墨印花用白色涂料墨水的稳定性和遮盖力明显优于同等条件下TiO2所制备的涂料墨水。     

硅烷偶联剂对聚甲基丙烯酸甲酯/二氧化硅纳米复合材料结构与性能的影响

采用乙烯基三乙氧基硅烷(WD-20)作为偶联剂,通过溶胶-凝胶法合成了聚甲基丙烯酸甲酯(PMMA)/二氧化硅(SiO₂)纳米复合材料,采用紫外-可见光谱、红外光谱、扫描电子显微镜和热机械分析等研究了材料的结构和性能.结果表明,WD-20的加入对纳米复合材料透明性、耐热性能和微观形态结构有较大影响,随着WD-20用量的增加,纳米复合材料透明性增加,SiO₂分散相尺寸变小,玻璃化转变温度增加.当WD-20与四乙基原硅酸盐（TEOS）之比为0.2时,所制备的纳米复合材料的溶胶分数为6%、玻璃化转变温度为250 ℃以上、可见光透过率在80％以上、SiO₂分散相尺寸小于100 nm.     

纳米复合材料H6P2W18O62/TiO2-ZrO2（P123）的制备与微波辅助光催化降解甲基橙

在模板剂(C3H6O.C2H4O)x(P123)的作用下,采用溶胶-凝胶-程序升温溶剂热一步法制备了纳米复合材料H6P2W18O62/TiO2-ZrO2(P123)。通过傅里叶-红外光谱(FT-IR)、紫外-可见漫反射(UV-Vis/DRS)、X-射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜配合X-射线能量色散谱仪(SEM-EDS)和N2吸附-脱附等测试手段对其组成、结构和表面物理化学性质等进行了表征。结果表明,所合成的纳米复合材料H6P2W18O62/TiO2-ZrO2(P123)中多酸结构保持比较完整,复合材料具有锐钛矿晶型结构,属于介孔材料,模板剂P123使合成产物分布更加均匀。选取甲基橙(MO)作为模型分子,考察了该复合材料在微波辐射作用下的光催化性能。实验结果表明,该复合材料有较好的光催化活性,对甲基橙的降解效果明显高于TiO2、H6P2W18O62、H6P2W18O62/TiO2和H6P2W18O62/TiO2-ZrO2。     

Nanocomposite polymer electrolytes by in situ polymerization of methyl methacrylate: For electrochemical applications

Hybrid materials, which combine properties of organic–inorganic materials, are of profound interest owing to their unexpected synergistically derived properties and are considered as innovative advanced materials promising new applications in many fields such as optics, electronics, ionics and mechanics. Inorganic fillers are added to polymers in order to increase some of the properties of the compounds. These hybrid polymeric materials are replacing the pristine polymers due to their higher strength and stiffness. In the present work, studies concerning the preparation of poly (methylmethacrylate) [PMMA] and the nanocomposites PMMA/SiO₂, PMMA/TiO₂ are reported. These nanocomposite polymers were synthesized by means of free radical polymerization of methylmethacrylate, further “sol–gel” transformation‐based hydrolysis and condensation of corresponding alkoxide was used to prepare the inorganic phase during the polymerization process of MMA. Electrolytes were synthesized based on these nanocomposite polymers and have shown superior properties as compared to conventional polymer electrolytes. The nanocomposites and the nanocomposite polymer electrolytes (NPEs) with different lithium salts were investigated through an array of techniques including FTIR and calorimetry along with the electrochemical and rheological techniques. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

有机玻璃基底镀TiO2/Au/TiO2膜用底涂层的制备

以溶液聚合工艺制备了数均分子量在20000左右、羟基值为40～48mgKOH/g的丙烯酸树脂,将该树脂与固化剂N-75按适宜的比例混合为底涂层,淋涂于800mm×400mm的洁净有机玻璃(PMMA)表面,在真空镀膜机中依次沉积TiO2膜和Au膜,获得了PMMA/底涂/TiO2/Au/TiO2膜。研究了不同配方的丙烯酸树脂合成工艺和混合溶剂的选择及配比对PMMA/底涂/TiO2/Au/TiO2膜性能的影响,讨论了"形变"的原因。研究发现,当乙酸丁酯和丙二醇甲醚醋酸酯以1∶1的质量比为混合溶剂,树脂和混合溶剂的质量比为1∶3时,所得涂膜具有良好的附着力。以Tego270为助剂,其质量分数为0.2%时能有效减少薄膜的"形变"缺陷。     

改性纳米TiO2固相光催化降解LDPE薄膜的研究

采用苯乙烯接枝改性纳米二氧化钛（TiO2-g-PS）颗粒作为催化剂,制备了一种新型可光催化降解的TiO2-g-PS /LDPE纳米复合薄膜,并在空气中紫外光照下进行了薄膜的固相光催化降解。利用热失重、傅立叶红外光谱和扫描电子显微镜等对光照前后纯LDPE、TiO2/LDPE和TiO2-g-PS /LDPE复合薄膜进行分析表征。结果表明,改性颗粒的催化活性较高,能有效地降解聚乙烯薄膜,复合薄膜经紫外光照336 h后,光降解失重率达到36.2 %。     

Morphological and mechanical characterization of a PMMA/CdS nanocomposite

Thick film of poly(methyl methacrylate) (PMMA)/CdS nanocomposite have been synthesized by the solution casting process. The nanostructure of the CdS particles has been ascertained through the small angle X-ray scattering (SAXS) technique. The surface morphological characterization of the PMMA/CdS nanocomposite has been done through scanning electron microscopy (SEM) analysis. The variation of mechanical loss factor (Tanδ) with temperature and tensile properties of prepared samples have been studied using Dynamic Mechanical Analyzer (DMA). This study reveals that the glass transition temperature (T_g), Young’s modulus, and fracture energy of the PMMA/CdS nanocomposite are greatly influenced by the existence of interfacial energetic interaction between dispersed CdS nanoparticles and the matrix of PMMA.     

A facile one-step solvothermal synthesis of graphene/rod-shaped TiO₂ nanocomposite and its improved photocatalytic activity

Graphene sheets were obtained through solvothermal reduction of colloidal dispersion of graphene oxide in benzyl alcohol. The graphene/rod-shaped TiO(2) nanocomposite was synthesized by this novel and facile solvothermal method. During the solvothermal reaction, both the reduction of graphene oxide and the growth of rod-shaped TiO(2) nanocrystals as well as its deposition on graphene occur simultaneously. The photocatalytic activity of graphene/rod-shaped TiO(2) and graphene/spherical TiO(2) nanocomposites was compared. In the photocatalytic degradation of methyl orange (MO), the graphene/rod-shaped TiO(2) nanocomposite with the optimized graphene content of 0.48 wt% shows good stability and exhibits a significant enhancement of photocatalytic activity compared to the bare commercial TiO(2) (P25) and graphene/spherical TiO(2) nanocomposite with the same graphene content. Photocurrent experiments were performed, which demonstrate that the photocurrent of the graphene/rod-shaped TiO(2) nanocomposite electrode is about 1.2 times as high as that of the graphene/spherical TiO(2) nanocomposite electrode. The photocatalytic mechanism of graphene/rod-shaped TiO(2) nanocomposite was also discussed on the basis of the experimental results. This work is anticipated to open a possibility in the integration of graphene and TiO(2) with various morphologies for obtaining high-performance photocatalysts in addressing environmental protection issues.     

通过RAFT聚合制备经GMA偶联的PMMA/TiO2杂化纳米复合物

利用表面修饰法合成了常用单体甲基丙烯酸缩水甘油酯(GMA)修饰的TiO2纳米粒子。以甲基丙烯酸甲酯(MMA)为单体,S-1-十二烷基-S′-(α,α′-二甲基-α″-乙酸)三硫代碳酸酯(DDACT)为RAFT试剂,在纳米TiO2表面进行可逆加成-断裂链转移(RAFT)接枝聚合,PMMA"经表面接枝到(grafting through)"改性后的纳米TiO2表面。结果表明,随聚合时间的增加,纳米TiO2表面接枝聚合物PMMA的量增加,颗粒的团聚得到明显减缓。     

Preparation and characterization of silica sol/fluoroacrylate core–shell nanocomposite emulsion

The silica sol/fluoroacrylate core?Cshell nanocomposite emulsion was successfully synthesized via traditional emulsion polymerization through grafting of KH-570 onto silica particles. Comparing the performance of the polyacrylate copolymer, the fluorinated polyacrylate copolymer and the silica sol/fluoroacrylate core?Cshell nanocomposite emulsion, we can come to a conclusion that the silica sol/fluoroacrylate core?Cshell nanocomposite emulsion presents significantly excellent performance in all aspects. The products were characterized by Fourier transform infrared (FTIR), photon correlation spectroscopy (PCS), transmission electron microscopy (TEM), thermogravimetry (TGA), Contact angle and UV?Cvis analyses techniques. The chemical structure of polyacrylate copolymer, fluorinated polyacrylate copolymer and silica sol/fluoroacrylate nanocomposite were detected by FTIR. The size and stability of emulsion latex particles were determined by PCS technique. TEM analysis confirmed that the resultant latex particle has the core?Cshell structure, obviously. The water absorption and contact angle data also showed that the silica sol/fluoroacrylate nanocomposite film has good hydrophobic performance. TGA analysis indicated the weight loss of the silica sol/fluoroacrylate nanocomposite film begins at around 350?°C which testifies its good thermal stability. The UV?Cvis spectroscopy analysis showed that the silica sol/fluoroacrylate nanocomposite film possess UV?Cvis shielding effect when the added volume amount of KH570 modified silica sol is up to 5?mL. Therefore, the excellent properties of hydrophobicity, thermodynamics and resistance to ultraviolet provide the silica sol/fluoroacrylate nanocomposite film with potential applications in variety fields. In addition, the formation mechanism of core?Cshell structure silica sol/fluoroacrylate nanocomposite latex particles was speculated.     

Synthesis and characterization of novel polyimide/SiO2 nanocomposite materials containing phenylphosphine oxide via sol‐gel technique

In this article, a series of novel polyimide/silica (PI/SiO₂) nanocomposite coating materials were prepared from tetraethoxysilane (TEOS), γ‐glycidyloxypropyltrimethoxysilane (GOTMS), and polyamic acid (PAA) via sol‐gel technique. PAA was prepared by the reaction of 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride (BTDA) and bis (3‐aminophenyl) phenyphosphine oxide (BAPPO) in N‐methyl‐2‐ pyrrolidone (NMP). BAPPO was synthesized hydrogenation of bis (3‐nitrophenyl) phenyphosphine oxide (BNPPO) in the presence of Pd/C. The silica content in the hybrid coating materials was varied from 0 to 20 wt %. The molecular structures of the composite materials were analyzed by means of FT‐IR and ²⁹Si‐NMR spectroscopy techniques. The physical and mechanical properties of the nanocomposites were evaluated by various techniques such as, hardness, contact angle, and optical transmission and tensile tests. These measurements revealed that all the properties of the nanocomposite coatings were improved noticeable, by the addition of sol‐gel precursor into the coating formulation. Thermogravimetric analysis showed that the incorporation of sol‐gel precursor into the polyimide matrix leads to an enhancement in the thermal stability and also flame resistance properties of the coating material. The surface morphology of the hybrid coating was characterized by scanning electron microscopy (SEM). SEM studies indicated that nanometer‐scaled inorganic particles were homogenously dispersed throughout the polyimide matrix © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

硅溶胶/含氟聚丙烯酸酯复合乳液的制备与表征

采用经典的St(o)ber法在常温下制备纳米级硅溶胶,用3-(甲基丙烯酰氧)丙基三甲氧基硅烷对其改性.在阴离子乳化剂和非离子乳化剂共同存在下,通过乳液聚合制备了硅溶胶/含氟聚丙烯酸酯复合乳液.表征了乳胶粒形貌,测试了共聚物组成及性能、乳液稳定性和乳胶膜性能.结果表明:乳胶粒有明显的核壳结构,乳液有良好的储存稳定性、稀释稳定性、高温和低温稳定性;硅溶胶/含氟聚丙烯酸酯复合乳胶膜吸水率达12.50％,对水的接触角为93 5°;复合物的热稳定性高于普通聚丙烯酸酯共聚物和含氟聚丙烯酸酯共聚物.