纳米ATO浆料分散性能的影响因素研究

采用硅烷偶联剂对纳米掺锑二氧化锡(ATO)粒子表面进行化学改性,将纳米ATO粉体分散于蒸馏水中制备成纳米ATO浆料,研究了分散剂种类,分散剂用量,硅烷偶联剂,硅烷偶联剂用量,分散时间和pH等参数对ATO纳米浆料分散效果的影响。当采用硅烷偶联剂KH560,其用量为浆料总质量的0.8%;嵌段型分散剂3275,其用量为浆料总质量的0.6%;pH=10时,可制备分散性能良好的纳米ATO浆料。     

正交实验优化纳米ATO浆料分散工艺

运用正交实验法研究了超声时间、pH值、分散剂种类、分散剂用量以及高速搅拌时间对纳米ATO浆料的分散稳定性的影响。结果表明,当分散剂为硅烷偶联剂KH-570、分散剂用量20%,超声分散时间2 h,pH值为10,高速分散时间为2h的条件下,纳米ATO水性浆料分散比较均匀。利用激光粒度分析仪测定分散均匀后的纳米ATO浆料,发现绝大部分的纳米ATO粒径都在150 nm以内,说明该工艺可以适用于纳米ATO浆料的分散。     

基于正交实验的纳米ATO浆料的分散稳定性研究

采用正交实验对纳米掺锑氧化锡(ATO)浆料的制备条件进行了优化,研究了磁力搅拌时间、分散剂种类、分散剂用量、pH值和超声分散时间对纳米ATO浆料分散稳定性的影响。实验结果表明:在磁力搅拌时间为1 h,分散剂用量为10%,pH值为10,分散剂为4#和超声分散时间为30 min的条件下,纳米ATO浆料的分散稳定性最好。     

纳米TiO_2在水中的分散与改性研究

为了使纳米TiO2能在水中良好稳定地分散,研究了分散剂的种类及用量、pH、改性剂的用量对纳米TiO2水分散体系稳定性的影响,采用重力沉降法、吸光度法、粒度法、Zeta电位法对分散与改性效果进行了分析与表征。研究结果表明:无机分散剂六偏磷酸钠(SHMP)对纳米TiO2的分散效果最好,当pH=9,SHMP用量为0.05 g时水分散体系稳定性最佳。硅烷偶联剂Z6030能有效地对纳米TiO2进行改性,其最佳用量为0.4 g,动态激光光散射(DLS)和傅里叶变换红外光谱(FT-IR)测试结果表明,硅烷偶联剂Z6030与纳米TiO2粒子表面的羟基相耦合或链接,以化学键的形式结合到纳米TiO2粒子表面。     

纳米ATO水性分散液的制备及其分散稳定性研究

采用球磨法制备了3种纳米锑掺杂二氧化锡(简称ATO)水性分散液,包括未加分散剂,以非离子型高分子分散剂改性和以阴离子分散剂与非离子高分子分散剂复合改性3种情况,并通过Zeta电位仪、激光粒度仪、透射电镜、静止沉降实验等测试方法对纳米ATO水性分散液的稳定性进行了表征.结果发现,ATO纳米颗粒通过分散剂复合改性后,其水性分散液的稳定性最佳,当阴离子分散剂与非离子高分子分散剂的质量比为1∶2,复合分散剂用量为ATO粉体质量的6%时,所得ATO水性分散液的稳定性最好.     

纳米ATO导电浆料的分散稳定性

将纳米ATO粉体分散于溶剂中制备成纳米ATO导电涂料.通过黏度测定和沉降实验,讨论了分散剂种类、pH等参数对制备浆料的影响,进行优化筛选.经粒径分布测定及扫描电镜观察,最终制得分散稳定性较好的纳米ATO浆料.     

纳米ITO水性浆料分散性能的影响因素研究

以ITO粉体为原料,通过球磨分散法研制ITO水性浆料;研究不同分散剂(PEG、PVP、曲通X-100)的用量、ITO粉体用量、球磨分散时间、pH值对纳米ITO浆料稳定性能的影响,采用沉降实验的方法来对浆料的稳定性进行表征与分析,研究结果表明,在pH=8.0,分散剂为PVP,分散剂用量为ITO粉体质量分数的10%,球磨分散时间为15 h,ITO浆料稳定性最好。     

纳米锑掺杂氧化锡的表面改性研究

以乙醇与水的混合溶液作为改性介质,将纳米锑掺杂氧化锡(Antimony Doped Tin Oxide,ATO)分散于介质中,利用硅烷偶联剂KH-570与纳米ATO表面羟基的脱水反应以及硅烷偶联剂间的缩合反应,制得了KH-570包覆的纳米ATO粉体。通过FTIR、XPS、TG、TEM以及亲油性的测试对纳米ATO粉体的表面结构以及性能进行了表征,探讨了纳米ATO的与硅烷偶联剂的表面接枝情况以及硅烷偶联剂与纳米ATO在弱极性条件下的反应机理。研究结果表明：在ATO纳米粒子表面接枝上了一层约7.36-7.73wt%的KH570,改性后的纳米ATO粒子的亲油性能以及分散性得到大幅度的提高,改性ATO在正丁醇能够稳定分散100h以上。其根本原因在于改性后纳米ATO表面形成了一个网络结构硅烷偶联剂的包覆层,赋予纳米ATO粒子的表面良好的亲油性能以及分散性能。     

纳米锑掺杂氧化锡的表面改性

将纳米锑掺杂氧化锡(antimony doped tin oxide,ATO)分散于乙醇与水的混合改性介质中,利用硅烷偶联剂KH-570与纳米ATO表面羟基的脱水反应以及硅烷偶联剂间的缩合反应,制得了KH-570包覆的纳米ATO粉体。用FTIR、XPS、TG、TEM对纳米ATO粉体的表面结构进行了表征,并通过亲油性的测试,考察了其分散稳定性。结果表明,在ATO纳米粒子表面接枝上了7.36%～7.73%(质量分数)的KH-570,改性后的纳米ATO粒子的亲油性及分散性得到大幅度提高,改性ATO在正丁醇中能够稳定分散100 h以上。     

纳米碳化硅在环氧树脂中的分散工艺研究

采用加入分散剂和超声波分散2种方法改进纳米SiC在环氧树脂中的分散,研究了分散剂种类和用量、分散方法对纳米SiC在环氧树脂中分散的影响。结果表明:分散剂DISPERBYK-2009的降粘效果最好,SiC/EP浆料的粘度下降达57.3%,浆料粘度随分散剂用量的增加呈现先降后升态势。通过添加粉体质量分数5%的分散剂DISPERBYK-2009并采用超声波分散15 min,实现了纳米SiC在环氧树脂中的均匀分散,成功制备了粒子细小、均匀分布的纳米SiC/EP复合材料。     

原位聚合法制备纳米ATO/PMMA乙醇分散液的研究

将纳米掺锑二氧化锡(ATO)粒子经过超声分散和偶联剂处理后,以甲基丙烯酸甲酯(MMA)为单体,用原位聚合法制备了纳米ATO/PMMA乙醇分散液。讨论了偶联剂种类、MMA与ATO质量比值、引发剂偶氮二异丁腈(AIBN)用量对纳米ATO/PMMA乙醇分散液分散稳定性的影响。确定了合适的偶联剂为乙烯基三叔丁基过氧硅烷(VTPS),最优工艺参数为m(MMA)∶m(ATO)=2,w(AIBN)=1.5%。往聚丙烯酸酯树脂加入该纳米ATO/PMMA乙醇分散液所制得的涂料,其涂膜同时具有良好的可见光透过率和近红外光阻隔性能。     

纳米ATO的表面修饰及抗静电腈纶的制备

以聚丙烯酰胺(PAM)为分散剂,制备纳米ATO(SnO2·Sb2O3)导电粉末水相悬浮液,并用硅烷偶联剂修饰,将修饰后的纳米ATO悬浮液加入到聚丙烯腈原液(NaSCN溶剂)中共混,得到蓝绿色的聚丙烯腈共混原液。采用Zeta纳米粒度与电位分析仪、热台偏光显微镜、红外光谱等仪器测试了纳米ATO微粒在聚丙烯腈原液中的分散性能;用流变仪研究了共混原液的流变性能。在中型湿法纺丝机上纺制了2h左右的腈纶纤维,不堵喷丝孔。测试了纤维的力学性能和抗静电性能,用DSC和TG研究了纤维的热性能。     

Influence of polymer–filler interactions on retraction behaviors of natural rubber vulcanizates reinforced with silica and carbon black

In general, silica‐filled rubber compounds contain a silane coupling agent to improve the filler dispersion and polymer–filler interactions. The silane coupling agent modifies the silica surface and makes crosslinks between the rubber and the silica. Influence of the modification of silica on the retraction behaviors of natural rubber (NR) vulcanizates reinforced with silica and carbon black was studied. Variation of the retraction behaviors of NR vulcanizates with filler composition was also investigated. The vulcanizates containing the silane coupling agent were recovered faster than those without the silane coupling agent. The recovery difference between the vulcanizates without and with the silane coupling agent increased with increased silica content. For the vulcanizates containing the silane coupling agent, the retraction behaviors were nearly the same, irrespective of filler composition. But, for the vulcanizates without the silane coupling agent, the vulcanizate was recovered more and more slowly as the silica content increased. The experimental results are explained with the polymer–filler interactions, modification of silica surface, and formation of crosslinks between silica and rubber. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 691–696, 2006     

Effect of chemical structure of silane coupling agent on interface adhesion properties of syndiotactic polypropylene/cellulose composite

To improve interaction between syndiotactic polypropylene (SPP) and fibrous cellulose (FC), effects of chemical structure of silane coupling agent on the reactivity for the surface hydroxyl group on the FC were studied by X‐ray photoelectron spectroscopy (XPS) measurement. Among the three kinds of the silane coupling agent, the 3‐aminopropyltrimethoxysilane (APTMS) showed the highest reactivity with the surface hydroxyl group on the FC, and the linear silane compound with methoxyl group was found to be suitable for the reaction. Although the morphology of the SPP/FC composite is hardly affected by the difference in the kinds of the silane coupling agent, the tensile properties were considerably different. In particular, in the case of using higher silane coupling agent solution (over 3 wt %), the chemical structure of silane coupling agent certainly affected the tensile properties of the SPP/silanized FC composite. It was found that the tensile properties were distinctly affected by the reactivity between the surface hydroxyl group on FC and the silane coupling agent. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

PMMA/ATO纳米复合材料的结构与导电性能

采用溶液共混的方式制备了聚甲基丙烯酸甲酯/纳米掺锑二氧化锡(PMMA/ATO)复合材料,分析了复合材料的微观相态结构及导电性能,并对复合材料的物理机械性能及热性能进行了研究.结果表明:经过钛酸酯偶联剂处理的纳米ATO在PMMA基体中分散良好,在含量较低的情况下即可获导电性能良好的复合材料;当纳米ATO的质量分数为5%时,复合材料具有良好的物理机械性能;纳米ATO在PMMA基体中起到了交联点的作用,使其玻璃化转变温度随着ATO的增加而升高,从而改善了PMMA的耐热性能.     

硅烷偶联剂的偶联作用机理及其在密封胶中的应用

硅烷偶联剂作为一种重要助剂,在密封胶、胶黏剂、金属防腐及涂料等领域都有广泛的应用。综述了硅烷偶联剂的偶联作用机理,包括化学键合理论、变形层及拘束层理论、摩擦层理论及应力松弛假说等。介绍了硅烷偶联剂在密封胶领域的几种典型应用方法,主要包括基材表面的底涂、填料颗粒的表面改性及作为助剂与基础聚合物共混等。讨论了不同使用条件下影响硅烷偶联剂使用效果的因素,并对硅烷偶联剂的发展进行了展望。     

磷石膏晶须表面改性及其在PP中初步应用

采用硅烷偶联剂KH570对磷石膏晶须进行超声波表面改性。考察了改性时间、改性温度、改性剂用量等条件对磷石膏晶须的表面改性影响。并分析了KH570对磷石膏晶须改性作用机理。结果表明:当KH570的用量为磷石膏晶须质量的5%,改性时间为80 min,改性温度在50℃时,获得最佳的改性效果。由红外光谱分析可知磷石膏晶须表面羟基与KH570发生了化学键的作用。改性的磷石膏晶须/PP复合材料的相容性较好,复合材料力学性能较纯PP材料有所提高。     

硅烷偶联剂封端改性水性聚氨酯的研究

以聚醚多元醇(GE210)、异佛尔酮二异氰酸酯(IPDI)和α,α-二羟甲基丙酸(DMPA)为原料合成了基础聚氨酯(PU)预聚体,然后以1,4-丁二醇进一步扩链制得了水性聚氨酯(WPU)乳液,最后以偶联剂γ-氨丙基三甲氧基硅烷对PU分子进行封端,得到了稳定的改性PU乳液。通过对偶联剂的用量和封端条件等研究,确定了适合硅烷改性WPU的方式。实验结果表明,当w(硅烷偶联剂)=4%～5%时(占树脂的质量分数),硅烷偶联剂封端改性WPU乳液具有较低的表面张力,其胶膜的力学性能和耐水耐溶剂性能均相当优异。     

Improvement of Water Lubricity of Titanium Nitride–Titanium Composite by Hydrophilic Silane Coupling Agent

To improve the lubricity of titanium nitride–titanium (TiN–Ti) composite in water, a hydrophilic silane coupling agent was added to the water. The tribological characteristics of the TiN–Ti composite in distilled water and in aqueous solutions of the silane coupling agent ranging in concentration from 0.001 to 0.1 mol/L were investigated. The silane coupling agent effectively inhibited the formation of a thick titanium oxide layer, which degrades the water lubricity of Ti-based materials, on the sliding surface. The lubricity of the TiN–Ti composite in the aqueous solutions of the silane coupling agent was much better than that in distilled water.     

Water-repellent all-cellulose nanocomposite using silane coupling treatment

Water-repellent all-cellulose nanocomposite (ACNC) was made using the silane coupling agent dodecyltriethoxysilane. The ACNC, consisting of cellulose nanofibers incorporated into a cellulosic matrix, was prepared by reducing crystallinity in the surface of the cellulose nanofibers using DMAc/LiCl solvent, followed by applying pressure and drying. The ACNC surface turned from hydrophilic to hydrophobic by silane coupling treatment. X-ray photoelectron spectroscopy (XPS) measurements confirmed the existence of the silane coupling agent on the surface after treatment. As silane concentration increased, the water contact angle of treated ACNC increased, to a maximum value of 93°. Thermogravimetric analysis and atomic force micrographs showed a multilayered treatment. The silane treated ACNC showed lower water absorption compared to that of untreated one. The silane coupling treatment was also found to increase the mechanical performance of ACNC. Creation of a hydrophobic surface reduces the potential damage associated with water in outdoor applications of ACNC.