季铵盐接枝提高玻璃纤维膜表面Zeta电位

以玻璃纤维膜为基体,通过等离子处理,再进行化学接枝有机硅季铵盐,制备出荷正电玻璃纤维膜。采用扫描电子显微镜(SEM)、全衰减反射-傅里叶红外光谱图(ATR-FTIR)、X射线光电子能谱分析(XPS)、热重分析(TGA)等对改性玻璃纤维膜的结构与性能进行表征。采用Zeta电位法考察电解质溶液的种类、浓度、pH对改性玻璃纤维膜表面Zeta电位的影响。结果表明:季铵盐在玻璃纤维膜上的接枝量为2.47%;电解质种类对膜表面Zeta电位值影响较大,电解质浓度对Zeta电位测试稳定性影响较大;Zeta电位随pH的升高而下降,在pH值为7.0的0.001 mol/L的KCl溶液条件下,改性玻璃纤维膜表面Zeta电位提高到27.35 mV。     

苯乙烯共聚物包覆颜料及其超细化

通过添加吸附促进剂的方法,采用苯乙烯-丙烯酸丁酯-丙烯酸共聚物(PSAA)对有机颜料进行表面包覆改性,并制备了稳定性良好的分散体系,探讨了制备工艺对改性后颜料粒径、Zeta电位和分散体系性能的影响。结果表明,体系粒径和Zeta电位的绝对值随着PSAA用量的增加而逐渐增加,当PSAA用量增长到颜料总重的30%后,粒径增幅明显变大,Zeta电位的绝对值基本不再变化,离心稳定性达到最高;吸附促进剂滴加速度为1.5g/分钟,研磨转速为2000转/分钟时,所制备的改性颜料粒径较小。     

改性钙基膨润土对水泥浆体悬浮性的影响

通过对钙基膨润土(Ca-BT)进行改性,采用X射线衍射(XRD)、扫描电子显微镜(SEM)、激光粒径分布和zeta(ζ)电位进行表征,再结合对水泥浆体泌水率测试,研究了改性膨润土对水泥浆体悬浮性的影响.结果表明:Ca-BT经机械改性后,颗粒粒径显著减小,但对 ζ电位影响不大;Ca-BT经化学改性后 ζ电位绝对值明显增大,由-4.9 mV增至-32.9 mV;Ca-BT经机械化学改性后颗粒粒径明显减小且ζ电位绝对值增大,晶体层状结构破坏部分剥离为单片层,显著提高水泥浆体的悬浮性;在水泥浆体中掺入经机械化学改性的Ca-BT,其中改性剂掺量为7％时,搅拌均匀静置2 h后泌水率为4.46％最低,体系悬浮性最好.     

高压均质中焦磷酸钠对凹凸棒土微结构和黏度的影响

采用高压均质技术对凹凸棒黏土进行焦磷酸钠改性,考察了高压均质压力和焦磷酸钠浓度对改性凹凸棒黏土黏度的影响.同时采用FTIR、XRD和SEM进行了结构表征,测定了改性前后凹凸棒黏土的BET比表面积、组成和Zeta电位.结果表明,高压均质过程可显著影响焦磷酸钠改性凹凸棒黏土的理化性能.在焦磷酸钠质量百分比为0.5％和高压均质压力为20 MPa的条件下,改性凹凸棒黏土有最高的黏度,与未高压均质样品相比,黏度提高了38％.     

SEDS工艺制备丝素纳米颗粒及其表征

以丝素蛋白为原料,以六氟异丙醇为溶剂,采用超临界流体强制分散溶液（SEDS）工艺制备了丝素纳米颗粒。单因素实验考察了压力、溶液浓度、溶液流速和CO2流速等因素对丝素纳米颗粒平均粒径分布的影响,并通过Zeta电位、HS-GC、FTIR、XRD和DSC等技术手段对制备的丝素纳米颗粒进行了表征。动态激光光散射仪检测结果表明：随压力、溶液浓度和流速的增大,丝素纳米颗粒平均粒径增大;随CO2流速的增大,丝素纳米颗粒平均粒径减小,最小达到298nm。丝素纳米颗粒Zeta电位为?39mV。HS-GC表明丝素纳米颗粒有机溶剂残留量为20μg/L。FTIR表明经SEDS工艺处理后丝素化学结构和官能团不会发生变化。XRD和DSC显示经SEDS工艺处理后丝素内部分子结构发生重排,由无规则卷曲向β折叠转换。     

碳酸钙疏水改性及性能表征

采用单一改性剂油酸、硬脂酸、二甲基硅油及复合改性剂对碳酸钙颗粒进行疏水改性。介绍了改性碳酸钙的作用机理。探讨了改性剂种类和加入量对碳酸钙颗粒表面疏水程度的影响,并通过活化度表征疏水程度。采用红外光谱仪表征改性前后碳酸钙的结构,说明改性剂被引入到了碳酸钙颗粒表面上;采用Zeta电位仪测定改性前后碳酸钙随pH变化的Zeta电位,得知改性碳酸钙的Zeta电位受pH影响比较大;采用激光粒度仪测定改性前后碳酸钙的粒径,得知改性碳酸钙比未改性碳酸钙的平均粒径小,且其分散稳定性要优于未改性碳酸钙。该研究也提供了随改性剂种类和加量变化来调整颗粒表面疏水程度的方法,有一定实际意义。     

硅烷偶联剂改性粉煤灰基白炭黑及其分散性能

采用3种硅烷偶联剂3-氨丙基三乙氧基硅烷(APTES)、3-巯丙基三乙氧基硅烷(MPTES)与3-(2,3-环氧丙氧)丙基三乙氧基硅烷(GPTES)对粉煤灰基白炭黑进行表面改性。借助FTIR、TGA、Zeta电位仪和SEM考察并比较了氨基、巯基、环氧类硅烷偶联剂对改性白炭黑分散性能的影响。结果表明,3种硅烷偶联剂均可接枝于白炭黑表面,且改性后白炭黑粒子分散性得到明显改善。分散性不仅与改性后白炭黑产品粒径相关,而且与硅烷偶联剂的负载量有一定关联。其中,MPTES对白炭黑的改性效果最佳,当pH为10、MPTES/SiO_2物质的量比为1.0∶1.0时,得到的改性白炭黑在乙醇中的分散性最好,粒径为557 nm,Zeta电位绝对值为36.43 mV。     

硅疏水改性聚胺阻垢剂的制备及其性能

用γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)、1-氯辛烷对低相对分子质量聚乙烯亚胺(PEI)进行疏水接枝改性,得到了含硅疏水改性聚胺阻垢剂。通过FTIR、TG、粒径分析、Zeta电位测试等分析改性后聚胺阻垢剂的结构与性能。结果表明,改性后产物热稳定性提高、黏度增大、表面张力降低、溶液粒径增大。将改性聚胺阻垢剂用于分散铝硅酸钠颗粒,对处理前后的颗粒进行红外光谱表征,并通过对悬浮分散液进行稳定性、颗粒沉降等测试,评价聚胺阻垢剂的阻垢分散性能并初步讨论其分散机理。当m(PEI, M_w=10000)∶m(KH560)∶m(1-氯辛烷)=10∶2∶0.5,反应时间6 h,反应温度75℃时,合成的阻垢剂分散性能最佳。当结疤的质量浓度为30 g/L时,悬浮液颗粒沉降速度达到最低值0.047 cm/d,沉降速率减小程度达到94.8%,分散性显著提高。经过改性后的PEI在氧化铝工业生产中具有高效的阻垢作用,可通过在工厂进行条件优化,进一步替代传统的强酸型阻垢剂,减小管道腐蚀程度,降低能耗。     

硅溶胶的有机改性及应用

为了提升纳米硅溶胶在硅片上SiO_2薄膜的化学机械抛光(CMP)效率,用硅烷偶联剂KH550在酸性条件下对硅溶胶进行表面改性。对得到的产物进行化学机械抛光及通过粒度分析仪分析氧化硅粒径和Zeta电位变化,并通过红外光谱分析仪和原子力显微镜分析氧化硅颗粒表面是否接枝上了硅烷偶联剂。结果表明,经过改性后的硅溶胶在红外测试中3 400 cm^(-1)附近和1 616 cm(-1)附近和1 616 cm^(-1)附近出现了N—H的伸缩和弯曲振动峰;原子力显微镜探针离开氧化硅颗粒表面时存在粘弹性;用抛光机测得使用改性后的硅溶胶比使用未改性的硅溶胶去除速率有所提高,并在改性含量0.05%时,去除速率达到最快;改性后的硅溶胶粒子Zeta电位趋向于正向增大,且随着加入改性剂的量从0～0.1%逐渐增加,硅溶胶粒子Zeta电位向正电荷位移更加明显;对未改性的硅溶胶和加入0.05%KH550改性后的硅溶胶进行动态光散射分析,硅溶胶经过改性后粒径D_(25)由65.3 nm增大到73.2 nm,粒径D_(50)由79.2 nm增大到83.5 nm,粒径D_(99)由154.1 nm减小至131.8 nm,而用静态光散射分析时,硅溶胶经过改性后粒径D_(10)由69.0 nm变化为69.6 nm,粒径D_(50)由99.1 nm变化为100.8 nm,粒径D_(99)由191.2 nm变化为194 nm,可以看出D_(10),D_(50),D_(99)基本没有发生变化。红外实验和原子力实验证明KH550成功地接枝到颗粒表面;加入改性剂KH550后,不仅改变了氧化硅表面Zeta电位,也改变了水化层;同时使小粒径胶粒的水化层变厚,大粒径的水化层变薄,使Zeta电位由负电荷变为正电荷,从而影响到在硅片上SiO_2薄膜的抛光效率。     

磺甲基酚醛树脂在水中的分散特性

考察了SPF(磺甲基酚醛树脂)在去离子水、氯化钠溶液和不同pH溶液中的分散特性,并对分散体系浊度变化规律、分子聚集体尺度和Zeta电位进行了测定。研究结果表明:SPF在去离子水中具有良好的分散稳定性,分子聚集体粒径较小;在低氯化钠浓度下,体系稳定性较好,浊度不随时间增加;盐浓度增加后,Zeta电位绝对值减小,体系失去分散稳定性,浊度随时间显著增加;当pH大于1.95时,体系分散稳定性较好,随着pH的降低,Zeta电位绝对值和体系分散稳定性降低,而浊度随着时间增加。     

Synthesis and characterization of styrene butadiene rubber—Bentonite clay nanocomposites

In the present study, naturally occurring unfractionated bentonite clay was used to prepare styrene butadiene rubber/bentonite clay nanocomposite by latex stage blending. The bentonite clay was organo‐modified by in situ resol formation by the reaction of resorcinol and formaldehyde. The latex clay mixture was co‐coagulated with acid. The resulting clay masterbatch was compounded and evaluated by Fourier Transform Infrared spectroscopy, X‐ray diffraction (XRD), Transmission Electron Microscopy (TEM), Energy Dispersive X‐ray spectroscopy (EDS), Scanning Electron Microscopy, Thermogravimetric analysis, and Differential Scanning Calorimetry. XRD showed that the interplanar distance of the in situ resol‐modified bentonite clay increased from 1.23 to 1.41 nm for the unmodified bentonite. TEM analysis indicated partial exfoliation and/or intercalation. EDS (Si and Al mapping) of the clay revealed the nature of the dispersion in the nanocomposites vis‐à‐vis the conventional styrene‐butadiene rubber (SBR)/bentonite clay composite. Thermogravimetric analysis was used to compare the decomposition trends of the SBR/clay nanocomposites with the SBR/clay composite. The glass transition temperature of SBR/clay nanocomposites increased as compared with that of neat SBR. Substantial improvement in most of the other mechanical properties was also observed in case of the nanocomposites. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

功能有机膨润土的制备及在颜料防沉中的应用

本文利用自行设计合成的环氧季铵盐与膨润土反应，合成了一种含有环氧基团的新型有机膨润土（Ep-clay)。傅立叶红外光谱证明环氧季铵盐以离子吸附和分子吸附的形成进入层间，接触角测试给出了该有机膨润土的界面参数，界面能54.4mJm^-2，临界表面张力45.8mJm^-2。该有机膨润土与普通有机膨润土（1831-clay)相比性能大幅提高；环氧树脂对该有机膨润土的润湿性提高了32%；在环氧体系中低剪切速率下，视粘度提高了一倍，而高剪切速率下，视粘度基本不变；对有机颜料的防沉性能提高25%。对无机颜料的防沉性能提高37.5%；涂膜的力学性能也得到提高。     

Mechanical and rheological properties of polypropylene/bentonite composites with stearic acid as an interface modifier

In this study, we present a study of polypropylene/bentonite composites where stearic acid was used as both a surface and interface modifier during the compounding of composites. The concentration of bentonite was 1.5, 2.5, 5.0, and 10 parts per hundred. The composites were characterized by impact resistance and tensile tests, rheological analysis, the dispersion state of the filler observed by optical microscopy, and interaction between bentonite and stearic acid, as analyzed by Fourier transform infrared spectroscopy. No chemical interaction was found between bentonite and stearic acid. Composites with modified bentonite and stearic acid used as interface modifiers increased the elongation at break; these samples also showed better dispersion of the filler in comparison with the other compounds. In addition, stearic acid acted as a lubricant, favoring the interaction of the polymer with the filler and decreasing the viscosity of the compounds. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42264.     

Synthesis and characterization of polyurethane/bentonite nanoclay based nanocomposites using toluene diisocyanate

Polyurethanes (PUs) prepolymers blended with bentonite nanoclay and without bentonite nanoclay were prepared by the reaction of toluene-2,4-diisocyanate (TDI) and hydroxyl terminated polybutadiene (HTPB), and the chain was further extended with 1,4-butane diol (1,4-BDO) to get final polyurethane nanocomposites (PUNC). A mixture of polymer and bentonite clay enriched in montmorillonite (MMT) was formed in solution polymerization, in which MMT dispersed depending on interaction of MMT with polymer chains. The molecular structure of the monomers and the prepared PU nanocomposites was confirmed by FTIR. A series of PUNCs were prepared by varying the percent compositions of bentonite nanoclay into the PU matrix. The existence of the clay in to the PU was confirmed by scanning electron microscope (SEM). SEM images verified the good dispersion of the bentonite nanoclay in PU matrix.     

分散剂对某膨润土矿分散行为影响研究

高纯度的膨润土具有很高的价值,而分级提纯对提高膨润土纯度非常重要.该论文以某地区膨润土为研究对象,在掌握矿石性质的基础上,对膨润土做分级试验,研究分散剂种类和用量对矿物各粒级产率和蒙脱石含量的影响,探究分散剂对矿物分散行为的影响规律和机理.研究结果表明:在分散剂用量均为0.5%时,由-5 μm粒级产率知药剂分散效果,聚丙烯酸钠>六偏磷酸钠>焦磷酸钠.聚丙烯酸钠具有高负电荷密度,使颗粒表面电位的绝对值增高,静电排斥作用增强,阻碍了颗粒间相互聚集和重力沉降,因而大大提高了矿浆的分散程度.     

Ni/bentonite catalysts prepared by solution combustion method for CO2 methanation

A 20 wt% Ni/bentonite catalyst was prepared by a solution combustion synthesis (SCS), which exhibited higher activity for the CO₂ methanation than that of an impregnation method (IPM), and the catalyst prepared by SCS showed a CO₂ conversion of 85% and a CH₄ selectivity of 100% at 300℃, atmospheric pressure, and 3600 ml·(g cat)^-1·h^-1, and the catalyst exhibited stable within a 110-h reaction. The results showed higher metallic Ni dispersion, smaller Ni particle size, larger specific surface area and lower reduction temperature in the Ni/bentonite prepared by SCS than that of IPM. And the Ni/bentonite prepared by the SCS moderated the interaction between NiO and bentonite.     

超细膨润土/环氧树脂复合材料的结构与热性能

采用TG-DTA、IR、SEM、马丁耐热和Daniel流动点测定等方法，研究了有机胺改性超细膨润土与环氧树脂的固化体系的结构及其性能。结果表明，有机胺改性膨润土与环氧树脂固化复合后，可形成由层问固化与层外固化相结合的结构，所得复合材料的耐热性能、分散性均有提高，其中活化有机膨润土／环氧树脂复合体系的分散效果和马丁耐热特性改善更加显著。     

Sulfur/sodium bentonite mixtures as sulfur fertilizers. 1. The effects of S/Na-bentonite ratios on the rate of dispersion and particle size distribution of elemental sulfur dispersed from laboratory-produced prills

Sulfur/sodium bentonite fertilizer prills were made by blending between 5 and 40% by weight of a swelling sodium bentonite clay with molten sulfur (S) and chilling droplets of the mixtures in oil. The resulting prills were hard and dust free and thus offered a suitable form for elemental sulfur (S°) transportation and application. The prills were stable at normal room temperature and RH. Prill strength was much reduced by prolonged storage at 80% RH. With 15% or more bentonite the bulk resistivity was sufficiently low that no electrostatic charge build-up was likely and consequently there was little risk of spontaneous combustion.Prills containing 10% or more bentonite disintegrated when placed in water and both the rate of dispersion and the fineness of the dispersed S° particles increased bentonite content. Bentonite contents of 15–20% appeared to offer the best combination of rapid prill dispersion, fine dispersed S° particle size, and high S° content.     

Ethylene vinyl acetate nanocomposites with hybrid silicate nanofillers of destabilized natural and commercial bentonites and organomontmorillonites

In this research, the interlayer destabilization process of bentonite was applied to gain a loosely packed, swelled, and disorganized clay layered structure for better polymer intercalation and filler dispersion during the fabrication of ethylene vinyl acetate (EVA) nanocomposites. Three different destabilization methods were applied to natural and commercial bentonites and their effects on swelling and platelets’ ordering of the clays were observed. X‐ray diffraction results suggest that the destabilization process through a combination of pH control and salt addition is more efficient in swelling both types of bentonite clays. This was supported by field emission scanning electron microscopy analysis where smaller, more loosely packed, and uniform platelets were observed due to swelling of both natural and commercial bentonite clays. The “destabilized” bentonites were used as the co‐nanofiller with the organically modified montmorillonite (OMMT) to form hybrid silicate nanofillers for EVA matrix reinforcement. Results show that the “destabilized” natural bentonite (NB) prepared by the combination of pH control and salt addition is most efficient in reinforcing the EVA matrix when combined with the OMMT by achieving 124.9% increment in tensile strength and 190.8% in toughness values. This could be related to the improved dispersion of bentonites upon the destabilization process that allows greater matrix–filler interactions in the nanocomposite system. In summary, the destabilization process through the combination of pH control and salt addition is the promising and practical technique to improve the dispersion of bentonites throughout the EVA matrix. Without the use of expensive and toxic chemicals, it can be adopted as a new approach to swell bentonites for more environmentally friendly nanocomposite technology. J. VINYL ADDIT. TECHNOL., 25:396–411, 2019. © 2019 Society of Plastics Engineers     

膨润土的开发应用

阐述了膨润土的结构特点、膨胀性、阳离子交换性、悬浮性、分散性、亲水性、稳定性、触变性和毒性等性能。根据制备膨润土的反应原理,介绍了生产膨润土的主要原料和3种制备工艺:湿法、干法和预凝胶法。同时,文章简介了膨润土的应用领域。