纳米TiO2硅烷改性参数的正交试验优化

目前纳米TiO2的表面化学改性法存在改性效果不佳、改性工艺冗长、反应条件复杂等缺陷.以KH-570硅烷偶联剂作纳米TiO2表面改性剂,以改性剂的掺量、偶联剂的水解pH值、反应时间和反应温度为影响因子,纳米TiO2的亲油化度为试验指标进行正交试验设计,并对试验结果进行验证分析和讨论.结果表明:KH-570偶联剂的掺量对纳米TiO2的亲油化度影响的显著性最大,改性最佳参数为KH-570掺量6.0％、改性时间4.5h、溶液pH值4.0、反应温度90℃;优化条件下纳米TiO2的分散稳定性和亲油性得到较大的提高.     

硅烷偶联剂KH-570对纳米二氧化硅的表面改性研究

为改善用作农药载体的纳米SiO2的分散性和疏水性,以硅烷偶联剂KH-570对纳米SiO2进行了表面改性,通过SEM、XRD、FTIR以及元素分析等表征方法对产物结构和性能进行了分析,结果表明,KH-570能够成功地对纳米SiO2进行改性,并且提高其分散性。最佳偶联改性的反应条件为：改性剂用量5%,改性时间5h。在此条件下,改性纳米SiO2的接枝率为11.7%。     

纳米TiO_2的改性及其性能研究

采用KH-570、正辛醇和辛酰氯分别对纳米TiO2进行改性,利用傅立叶红外光谱、差热/热重分析及X-射线衍射仪对改性前后纳米TiO2进行表征,结果表明纳米TiO2的改性为化学改性,改性剂与纳米TiO2表面羟基形成稳定的化学键,但并没有改变纳米TiO2的晶型结构。改性后的纳米TiO2在有机溶剂中的分散性和稳定性提高,尤其是KH-570改性纳米TiO2的效果最好,具有更强的疏水性。KH-570改性纳米TiO2与丙烯酸树脂复合后,能在树脂中均匀分散,不易团聚。     

温度及偶联剂用量对纳米TiO_2表面改性的影响

为了获得性能更为优异的纳米TiO_2,采用偶联剂KH-570对纳米TiO_2进行表面改性处理,研究偶联剂用量和温度对改性纳米TiO_2粒子功能单体影响。结果表明,随着硅烷偶联剂用量、温度的增加,改性后的TiO_2的相对接枝率和亲油化度都出现了先升高后下降的趋势。当硅烷偶联剂KH-570的用量为15%,反应温度为60℃时,改性纳米TiO_2功能单体相对接枝率和亲油化度达到最大值,分别达到9%和60%左右,接触角由32.8°增大为58.4°,其亲水性下降,性能最优。     

纳米ATO/TiO_2填料聚氨酯透明隔热涂料的制备与性能

为了制备隔热性能和透光性均较好的建筑物玻璃隔热涂料,以水性聚氨酯为成膜物质,纳米氧化锡锑(ATO)和纳米二氧化钛(TiO2)为填料,制备了水性纳米透明隔热玻璃涂料。采用扫描电镜、隔热膜温度测试仪及紫外分光光度计对纳米ATO与TiO2粒子在涂料涂膜中的分散稳定性、涂料涂膜的隔热性能及光学性能进行了分析,研究了纳米TiO2与ATO浆料配比及涂膜厚度对涂料涂膜性能的影响。结果表明:纳米ATO与TiO2浆料通过硅烷偶联剂KH-570改性,再辅以分散剂分散,经过高速分散和超声波分散后,与聚氨酯复合制得了分散稳定的复合透明涂料;该涂料不仅具有良好的成膜性能,且涂膜经红外灯照射60 s后,与空白玻璃对比,隔热温差最高达6.23℃,在保证良好的可见光透过率及隔热性能的前提下,最佳纳米TiO2与ATO浆料体积比为2∶20,最佳涂膜厚度为75μm,此时涂料涂膜隔热温差达3.60℃。     

纳米ATO粉体的表面改性研究

采用偶联剂对纳米ATO(氧化锡锑)粉体进行表面改性,综合考察了偶联剂的品种与用量、反应时间及反应温度对表面改性效果的影响,从而确定最佳表面改性条件.利用红外光谱(FTIR)、热重分析(TGA)以及光吸收率等表征手段来研究表面改性的效果及分散状况.结果表明,纳米ATO粉体表面改性的最佳条件为:选用硅烷偶联剂KH570,添加量为2份,反应水浴温度为80℃,反应5h.     

纳米SiO_2/有机硅聚丙烯酸复合防冰涂层的制备及性能研究

以有机硅聚丙烯酸为成膜物质,经γ-(甲基丙烯酰氧)丙基三甲氧基硅烷(KH-570)表面化学改性后的纳米SiO_2粒子(经甲苯-2,4-二异氰酸酯活化)为无机填料,制备纳米SiO_2/有机硅聚丙烯酸复合防冰涂层。利用红外测试(FT-IR)、热失重(TGA)、扫描电镜(SEM)等研究了纳米SiO_2表面化学改性的机制,探讨了纳米SiO_2用量对涂层表面形貌、浸润性及涂层与冰层之间粘附性能的影响。结果表明,KH-570化学改性提高了纳米SiO_2在涂层中的分散性并有效地提高了涂层表面的疏水性能,当KH-570化学改性后的纳米SiO_2用量为8%时,涂层表面水的接触角为150°,呈现超疏水特性;涂层与冰层之间粘附力随纳米SiO_2用量增加呈现下降趋势,当纳米SiO_2用量为8%时,涂层与冰层之间的粘附力仅为树脂涂膜的30%左右。KH-570化学改性后的纳米SiO_2与低表面能有机硅聚丙烯酸树脂的协同效应使涂层具有了良好的疏水防冰性能。     

锑掺杂二氧化锡纳米粉体的改性及在涂料中的应用

利用硅烷偶联剂、醇、油酸钠及自制高分子表面活性剂对锑掺杂二氧化锡纳米粉体(ATO)进行表面处理,研究了不同改性剂对粉体分散性的影响.以改性纳米ATO分散浆料和水性聚氨酯为原料,采用共混法制备了纳米复合涂料,并对其隔热性及基本性能进行测试.TEM及离心实验表明,ATO粉体经自制高分子表面活性剂或硅烷偶联剂改性后,分散性明显提高.性能测试表明:ATO粉体的加入能显著提高涂膜硬度及隔热性.     

纳米SiO2制备及改性

为了改善纳米SiO2的分散性,用溶胶-凝胶技术制备了纳米SiO2凝胶,并用不同改性剂对粉末进行了表面改性.采用透射电子显微镜(TEM)、X射线衍射(XRD)、粒度分析仪(PSA)、紫外-可见光分光光度计(UV-VS)等分析了纳米SiO2的粒径及分散性.结果表明,正硅酸乙酯的水解和缩合反应条件直接影响纳米SiO2粉体的粒径大小.KH-550硅烷偶联改性剂用量、改性时间等因素对改性效果有明显的影响.当改性剂用量为4.1%(质量分数),改性时间为2h时,可得到高分散性的纳米SiO2粉体.纳米SiO2粉末易发生团聚,只有对其进行表面改性,才能得到疏水性纳米SiO2粉末.     

纳米AlN/EP导热绝缘胶的制备及其性能研究

采用纳米AIN作为导热填料,经硅烷偶联剂KH-570表面改性后与环氧树脂(EP)共混制备了导热绝缘胶.通过红外光谱(FT-IR)、接触角方法对改性后纳米AIN进行分析和表征,结果表明,KH-570成功包覆到了纳米AIN表面,粉体由亲水性变为疏水性;对于纳米AIN/EP导热绝缘胶,随着改性纳米AIN填充量的增加,导热率呈上升趋势;当KH-570用量为3.5%、纳米AIN量为20%时,导热率达到0.632W/(m·K),是纯环氧树脂胶的3倍多;此时体积电阻率为2.6×1013Ω·cm,剪切冲击强度为11.9×1015J/m2.     

碳／蒙脱石复合材料和硅藻土粉体表面改性方法的研究

以自制的碳／蒙脱石复合材料、硅藻土为原料，用十六醇作为改性剂，研究超声分散和常规搅拌两种方法对碳／蒙脱石复合材料、硅藻土效果表面改性的影响，通过分光光度计、接触角测定仪和扫描电镜进行表征，结果表明，两种方法处理过的碳／蒙脱石复合材料、硅藻土粉体均较未处理前分散性好；超声分散方法有利于硅藻土的表面改性，而碳／蒙脱石复合材料用搅拌的方法效果更好。将不同改性方法制得的粉体材料及未改性粉体填充到天然橡胶中，其力学性能得到了提高。     

Mechanochemical Dispersion of Nanodiamond Aggregates in Aqueous Media

A technology of mechanochemical treatment (MCT) is introduced to modify nanodiamond (ND) surface aiming to obtaining a stable suspension with well-dispersed ND particles in aqueous medium. ND investigated in this paper is a purified product of nanometer-sized diamond synthesized by explosive detonation. As obvious aggregation and sediment were observed when the sample was added into deionized water, it is crucial to conduct deaggregation and dispersion investigations. Amid a series of mechanical treatments, i.e. grinding, stirring, ultrasonic and classification, some reagents are introduced to modify the newly created surface during aggregates comminution. For the co-effects of mechanical forces and surfactants, the mean size of particles was reduced and a stable system containing ND with narrow size distribution was prepared. Mechanism of surface reaction and modification are discussed, while AFM, Zetasizer3000HS, XRD, XPS and FTIR are utilized for the analysis. The functional chemical structure of ND p     

二甲基硅油对中铬黄颜料的表面改性

为了提高中铬黄颜料在漆料中的分散性,采用包覆改性法,以二甲基硅油为改性剂对中铬黄颜料进行表面改性,通过研究表面改性对颜料的吸油量、流动性、沉降时间、傅里叶红外光谱、扫描电镜图像的影响规律,对改性机理进行探讨。结果表明,使用二甲基硅油对中铬黄颜料进行表面改性可改善其在干燥状态下和有机聚合物基体中的分散性,随着改性剂用量的增大,中铬黄颜料的每百克吸油量由原来的30 g减小为16 g;经过二甲基硅油表面改性处理后,中铬黄粉体在煤油中的沉降时间由1 h延长到16 h左右;最佳工艺条件是二甲基硅油的质量为中铬黄质量的2.5%;二甲基硅油与中铬黄颗粒的表面吸附方式为物理涂覆;经过表面改性处理后,颗粒在干燥状态下的分散性明显提高。     

乙酸乙酯改性纳米氧化锌的制备及表征

利用乙酸乙酯作为改性剂,通过气相法对纳米氧化锌进行改性研究,用亲油化度考察改性效果;优化其改性工艺为:改性时间2h,改性温度120℃,改性剂的添加量为3.25%。通过透射电镜、激光粒度仪、接触角和沉降实验表明,改性后的纳米氧化锌颗粒均匀、团聚明显减弱、疏水性和分散性明显提高。     

微米TiO-2的表面改性及其分散性研究

为提高微米TiO2的分散性,采用偶联剂(KH570)法、无机包覆(铝包覆)法、超声法、非离子表面活性剂(PEG)法、阴离子表面活性剂(月桂酸钠)法,分别对微米TiO2进行表面改性。分析了改性前后微米TiO2的亲油化度、表面形态以及粒径大小。结果表明:超声法(功率90 W、时间15min、温度40℃、分散剂质量分数0.5%)和阴离子表面活性剂法(pH为5、月桂酸钠浓度0.050mol/L、时间30min)改性微米TiO2的效果比较显著,更有利于改善其分散性。     

Surface modification of nano-TiO2 with trimellitylimido-amino acid-based diacids for preventing aggregation of nanoparticles

Nanoparticles (NPs) are an essential material for science and technology, for instance in materials, medicals, and cosmetics. Controlling the dispersion of NPs is necessary to manage the properties of the final products. For this reason the surface modification of NPs is done by many techniques. In this work Nano-TiO₂ were modified using methanol as solvent and diacids based on natural amino acids as modifier at room temperature and using ultrasonic irradiation. Diacids were grafted onto the surface of TiO₂ NPs to improve the dispersion of the particles. The obtained modified TiO₂ were characterized by Fourier transform IR spectroscopy (FT-IR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) techniques. These analyses proved this modification process at room temperature was possible. TEM and FE-SEM showed that fairly good dispersed TiO₂ NPs were obtained after surface modification. Since TiO₂ and diacids which were used in this work are biologically active, the modified powder would be environmentally friendly.     

Dispersion effect and auto-reconditioning performance of nanometer WS<Subscript>2</Subscript> particles in green lubricant

This paper reported on dispersion effect and dispersing techniques of nanometer WS₂ particles in the green lubricant concocted by us. And it also researched on auto-reconditioning performance of nanometer WS₂ particles to the abrasive surfaces of steel ball from four-ball tribology test and piston ring from engine lubrication test. The treated and untreated nanometer WS₂ particles were analysed by infrared spectrum. And the elementary component and interior elementary distribution of abrasive surface repaired by nanometer WS₂ particles were analysed by multifunction electron spectrometer. The results showed that the combinative method of ultrasonic dispersion, mechanical agitation and surface modification could improve the dispersion uniformity and stability of nanometer WS₂ particles in the green lubricant effectively. And the optimal ratio of the mass between surface modifier and nanometer WS₂ particles was 1: 2.5, the optimal treating time was 5 h. And IR analysis indicated that surface modifier could react with hydroxide radicals on surfaces of WS₂ particles and modify the surfaces, and the long lipophilic groups on surfaces of nanometer WS₂ particles could stretch in oil adequately and form steric hindrance layers between particles which prevented particles from conglomerating and depositing. In addition, tribological tests and surface analysis indicated that there were WS₂ adsorption film and reaction film on abrasive surfaces during the tribological tests, which could fill and level up the furrows on abrasive surfaces. As a result, the abrasive surfaces were repaired effectively by nanometer WS₂ particles.     

聚合物基复合材料制备中碳纳米管的分散方法

综述了碳纳米管／聚合物复合材料制备过程中碳纳米管预先分散所使用的方法。为实现碳纳米管在聚合物中的分散，首先要求加入的碳纳米管本身具备足够的分散度。碳纳米管的分散方法主要有：表面化学修饰、分散剂分散、超声分散、机械分散、溶剂分散。     

铝酸酯干法改性纳米TiO_2及其在粉末涂料抗老化中的应用EI

利用铝酸酯偶联剂F-1对金红石型纳米TiO2进行干法改性。采用红外光谱(FT-IR)、紫外-可见分光光度计(UV-Vis)、接触角测试及扫描电镜(SEM)对纳米TiO2的改性效果进行了表征。以改性纳米TiO2作为紫外吸收助剂,研究了其对粉末涂料抗紫外光老化性能的影响。结果表明,铝酸酯偶联剂F-1是有效的改性剂,改性后的纳米TiO2具有疏水性,从而提高了其在粉末涂料中的分散性能。通过1368h人工加速老化发现,随着纳米TiO2含量的增加,纳米改性粉末涂料的耐候性能得到较大提高。当纳米TiO2质量分数为2.0%时,光泽度保持率可提高34.7%,色差减小27.3%。     

Supercritical hydrothermal synthesis and in situ organic modification of indium tin oxide nanoparticles using continuous-flow reaction system

ITO nanoparticles were synthesized hydrothermally and surface modified in supercritical water using a continuous flow reaction system. The organic modification of the nanoparticles converted the surface from hydrophilic to hydrophobic, making the modified nanoparticles easily dispersible in organic solvent. The addition of a surface modifier into the reaction system impacted the crystal growth and particle size as well as dispersion. The particle size was 18 nm. Highly crystalline cubic ITO with a narrow particle size distribution was obtained. The advantages of short reaction time and the use of a continuous reaction system make this method suitable for industrial scale synthesis.