不同工艺有机插层蛭石的制备及表征

以2倍蛭石阳离子交换容量的十六烷基三甲基溴化铵为插层剂,利用热液搅拌法、球磨法、煮沸法、熔融搅拌法等4种不同工艺对蛭石进行插层处理.对有机插层后的蛭石进行了粉晶X射线衍射、Fourier变换红外光谱和热重分析表征.结果表明:不同插层工艺会导致有机插层蛭石的层间距及微结构的变化.随着层间距的增大,蛭石层间的有机相含量逐渐增大.     

载银和有机化蛭石的制备及其抗菌性能

对蛭石钠化处理后,通过离子交换法对蛭石进行载银和有机化插层改性,制备了3种抗菌蛭石。通过抑菌圈和抗菌率实验研究了其抑菌抗菌性能和机理,用热重和X射线衍射分析了改性蛭石的抗菌持久性和层间结构。结果表明:载银、用十六烷基三甲基溴化铵有机改性、载银并有机改性的3种蛭石均对大肠杆菌和金黄色葡萄球菌具有明显的抑菌圈,对大肠杆菌和金黄色葡萄球菌的抗菌率均达到99.9%以上,所制备的抗菌蛭石具有极强的广谱抗菌能力;抗菌蛭石在水中浸泡60 d后仍具有长效抗菌性;有机改性蛭石的层间距由0.99nm可增大到4.33nm,其层间含有大量的有机插层剂,这为制备结构均匀的蛭石/有机复合材料提供了可能。     

不同蒙脱石的有机插层及聚合剥离

以成因、类型、性质不同的6种蒙脱石为原料,制备了有机插层和聚酰胺6／蒙脱石纳米复合材料。研究了蒙脱石矿物类型、成分及阳离子交换容量对其有机插层及聚合剥离的影响。结果表明：有机插层蒙脱石层间距随插层剂用量及阳离子交换容量的增加而增加,低阳离子交换容量及高钠含量蒙脱石更有利于插层剥离。钠化对蒙脱石有机插层影响不明显。     

聚氨酯/有机蒙脱土纳米复合材料的结构与性能Ⅰ.水基端羟基阳离子聚氨酯改性蒙脱土

合成了一系列不同相对分子质量的水基端羟基阳离子聚氨酯(WHTCPU),用其作为插层剂对蒙脱土(MMT)进行有机改性,通过阳离子交换得到含有活性羟基官能团的有机MMT。用广角X射线衍射、傅里叶变换红外光谱、透射电子显微镜、原子吸收光谱和显微电泳法等对改性后MMT的结构、性能进行了分析表征。结果表明,经WHTCPU改性的MMT是含有活性羟基官能团的有机MMT;当NCO/OH的摩尔比为1.5/2时,MMT层间距由原来的1.264 nm扩大到2.025 nm,此时有机MMT的阳离子交换能最低;经过WHTCPU改性的MMT粒子的电性得到反转。     

蛭石高附加值产品的开发及应用——有机插层蛭石的制备

分别以0．5,1,1．5,2倍蛭石阳离子交换容量的十六烷基三甲基溴化铵,十二烷基三甲基溴化铵和十六烷基三甲基氯化铵为插层剂,利用热液搅拌法对蛭石进行插层处理。对有机插层后的蛭石进行分析表征。实验结果表明：插层剂使用十六烷基三甲基溴化铵和十六烷基三甲基氯化铵效果好,其用量为200％时插层处理效果最好。     

RPUF／蛭石复合材料的制备及阻燃性能研究

用酸化、钠化对蛭石进行结构修饰,以十六烷基三甲基溴化铵(HDTMA·Br)为插层剂,制备了有机化蛭石(OVMT)。XRD 分析表明:HDTMA~ 已完全插层,蛭石的层间距由改性前的1.49 nm 增大到4.53 nm。将 OVMT与聚磷酸铵(APP)复配用于硬质聚氨酯泡沫塑料(RPUF)的阻燃,氧指数测试得出:当 OVMT 和 APP 添加量分别为5%和10%时,极限氧指数达到26.8%,比单独添加7%OVMT、10%APP 分别高出5.4%和3.2%;DSC 和 TG测试表明:与纯 RPUF 相比,复合材料吸热峰温度从358.1℃提高到369.6℃。     

插层聚合中蒙脱石的有机化研究

用来插层聚合的蒙脱石一般都要经过有机化处理,即用有机阳离子(插层剂)将无机阳离子交换出来,让蒙脱石层间距离得到增大,以便有机分子的进入。蒙脱石的有机化处理一般采用一次插层法,文章采用了一种新的二次插层法对蒙脱石进行有机化处理,并通过XRD、IR、TEM等手段,对一次插层法和二次插层法的效果进行了比较,确定了二次插层法为一种较为理想的蒙脱石有机化方法。     

有机蒙脱土的制备及性能表征

以天然蒙脱土(MMT)为原料,用季铵盐和氨基酸作为有机插层剂与蒙脱土层间的阳离子进行交换,优化反应条件(改性时间、温度和搅拌速率),制备出层间距不同的有机蒙脱土,用FT-IR、XRD、TEM及TG对产物进行表征.结果表明,4种有机插层剂都已进入蒙脱土的层间,蒙脱土的层间距由1.25 nm增加到1.82～4.05 nm,其中,以1631-Cl为插层剂,改性时间为4 h,改性温度为80 ℃,搅拌速率为300 r/min时,制得的有机蒙脱土层间距大且晶形良好.     

有机插层剂对聚酰胺6／MMT纳米复合材料制备的影响研究

以烷基胺、季铵盐和氨基酸作为有机插层剂与蒙脱土片层进行阳离子交换，制备出层间距不同的有机蒙脱土。采用熔融插层法和原位聚合法分别制备聚酰胺（R％）／蒙脱土（MMT）纳米复合材料，并利用XRD、FT-IR、TEM对有机蒙脱土及纳米复合材料进行结构表征。研究结果表明：用烷基胺、季铵盐和氨基酸有机插层剂改性的蒙脱土层间距由原来的1．25nm分别增大到3．21nm、3．99nm和1．82m；季铵盐有机插层剂更适用于熔融插层法制备PA6／MMT纳米复合材料，而氨基酸有机插层剂更适用于原位聚合法制备PA6／MMT纳米复合材料。     

不同表面活性剂制备有机蒙脱土

分别利用阳离子表面活性剂十六烷基三甲基溴化铵、十六烷基三甲基氯化铵和阴离子表面活性剂十二烷基磺酸钠制备了有机蒙脱土,并通过红外光谱分析和X-射线衍射分析对其进行了表征。结果表明,有机插层剂已进入蒙脱土的层间,蒙脱土的层间距由1.24 nm分别增加到2.14,2.20和2.51 nm。沉降实验结果表明,这种有机蒙脱土在有机介质中表现出很好的分散性。     

Polyurethane/organic vermiculite composites with enhanced mechanical properties

In this article, a series of polyurethane (PU)/organic vermiculite (OVMT) composites are prepared by intercalating polymerization. 1,4‐cyclohexane diisocyanate (CHDI) as hard segment of PU is designed to improve the decomposition temperature of composites. Vermiculite (VMT) is modified by method of cation exchange with octadecyl trimethyl ammonium bromide (OTAB); the resulting product OVMT with the function of physical cross‐linking disperses well in soft segment of PU polycarbonate polyol (PCDL), which improves the mechanical properties of composites obviously. This modification further enlarged the interlayer of OVMT and improved the properties of composites. The structure and properties of OVMT and PU/OVMT composites are characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, scanning electron microscope, and tensile strength test. The results showed that the layer spacing of OVMT increased 1.41 nm compared with that of VMT (the value of layer spacing of VMT is 0.96 nm) and further enlarged to 2.92 nm by the loading of PCDL. The tensile strength and the strain at break of PUCPB/OVMT (3.0%) composites reached 26.8 MPa and 443%, respectively. The temperature resistance of PUCPB/OVMT (3.0%) composites is above 300°C, which is more suitable for the steam channeling plugging of heavy oil. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43219.     

Intercalative redox polymerization and characterization of poly(4-vinylpyridine)–vermiculite nanocomposite

A new nanocomposite material consisting of poly(4-vinylpyridine) (PVP) and vermiculite is synthesized by the intercalative redox polymerization of VP in the gallery of copper(II) ion-exchanged vermiculite. The formation of a single filament of the polymer in the gallery is confirmed by the increase in gallery spacing of 4.7 Å as indicated by X-ray diffraction (XRD) analysis. Electron spin resonance studies confirm the presence of Cu(II) upon ion exchange and its absence following redox polymerization. The amount of polymer present in the gallery is found to be ∼18–19 mass % by thermogravimetric analysis. Confining the polymer to the gallery spacing in vermiculite results in enhanced thermal stability that is evident from the increase in the initial decomposition temperature by ∼300°C. Differential scanning calorimetry of the nanocomposite indicates that the polymer is confined to a restricted geometry because of the absence of a glass-transition temperature, which confirms the XRD finding. The IR absorption peaks corresponding to PVP and the expected PVP UV π–π* transition at 275 nm, along with the XRD and thermal data confirms that the gallery expansion is due to the PVP filament. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 555–561, 2001     

蛭石层状膜的制备及有机溶剂纳滤性能

受全球能源形势与环境问题影响,新型膜分离技术尤其是二维层状膜在分离领域展现出广阔的应用前景。然而,目前使用的二维纳米材料化学环境相对复杂,且膜制备成本高昂,限制了其工业化推广。天然蛭石廉价易得,剥离简单,表面只含有硅羟基且其含量易于调控,可精确调控所制备层状膜层间亲疏水性,实现有机溶剂的高效渗透和极性与非极性溶剂的高效分离。研究发现：蛭石层状膜展现出优异的极性溶剂分子传递能力,而非极性溶剂则相对较低,其中乙腈分子渗透性高达1650L/（m²·h·bar)（1bar=0.1MPa）,甲苯分子渗透性仅为37.8L/（m²·h·bar),乙腈与甲苯的分离因子高达43.6,展现出优异的分子分离性能。本文所制备蛭石层状膜具有1.36nm的规则平直层间传递通道,对分子动力学直径大于层间距的结晶紫（1.5nm）、亮蓝（1.6nm）、酸性黄14（1.9nm）等染料分子的截留率均大于90%,截留性能优良。同时,蛭石层状膜具有良好的压力循环稳定性及抗污染能力, 展现出巨大的分离应用潜力。     

Modification of montmorillonite by cationic polyesters

Novel types of polyester hydrochlorides and polyesters were synthesized from N-octyl- or N-methyldiethanolamine and organic acid chlorides with varying chain length. Their structure, molar masses and glass transition temperatures were determined. Montmorillonite (MMT) was modified by cation exchange with the polyester hydrochlorides. The basal spacing was not significantly influenced by the length of organic acid chain but increased with the length of the alkyl group attached to nitrogen atom. Cation ratio of MMT and hydrochloride must have been at least 1:3 for quantitative cation exchange, indicating that only a part of polycation chain adheres to MMT surface. Hydrophobicity and organic content increased with increased exchange ratio, reaching approximately constant levels at ratios above 1:3.     

改性剂种类对蒙脱土结构和性能的影响

为增加蒙脱土(montmorillonite,MMT)和有机物的相容性和研究插层剂种类对MMT结构和性能的影响,采用Cu,Co和Ni无机金属阳离子,十二烷基磺酸钠、十二烷基硫酸钠、α-烯烃磺酸盐和十二烷基苯磺酸钠等有机阴离子表面活性剂及十六烷基氯化吡啶、十六烷基三甲基溴化铵、十二烷基三甲基溴化铵等有机阳离子表面活性剂作为改性剂,对蒙脱土进行一次改性和二次改性,制备出一系列改性蒙脱土.研究了改性剂种类、插层方式、插层次序对插层效果的影响.X射线衍射分析表明:一次改性时,插层剂均能进入蒙脱土的层间,改性土的层间距由1.04nm增加到1.7～3.52nm;二次改性时,先阳离子后阴离子的插层顺序有利于层间距增大(4.14nm),还可利用配位作用将二次改性剂引入金属离子一次改性MMT中,使层间距增大.改性机理研究认为:阳离子改性机理为层间离子交换,而阴离子改性机理是改性剂和MMT表面形成了氢键.沉降实验表明一次改性土和二次改性土在有机溶剂中分散能力有所增强.     

Synthesis and characterization of novel organo-montmorillonites

Sodium Montmorillonite (NaMMT) has been modified via cation exchange reaction using three different organic cations. Basal spacings, interlamellar structure and thermal stability of these organo-montmorillonites (OMMT) clays have been characterized using wide angle X-ray diffraction (WAXD) and thermogravimetric analysis (TGA) techniques. Increase in the basal spacing due to organic modification is in good agreement with simple theoretical calculations based on van der Waals volume of the cationic ammonium ions. TGA characterization and analysis show that the amount of organic modifier in the OMMT's is in good agreement with theoretically calculated stoichiometric content expected for almost complete exchange of Na⁺ ions by organic cations. The OMMT's shows stepwise decomposition corresponding to initial weight loss from residual water desorption, followed by decomposition of the organic surfactant and the dehydroxylation of structural water of the montmorillonite layers.     

蛭石在重金属离子废水处理中的应用

蛭石是黏土矿物的一种,具有较大的比表面积和较强的阳离子交换容量,能有效去除废水中的重金属。文章总结了近年来蛭石吸附Cu2+、Cd2+、Ni2+、Pb2+等重金属离子的研究状况,发现其去除重金属离子的机理主要是离子交换和表面络合作用。分析了溶液pH值、吸附时间、蛭石粒径、蛭石投加量、溶液浓度对吸附效果的影响。指出应进一步加深对蛭石吸附机理和吸附后处置技术的研究,以及蛭石在实际工程上的应用推广。     

Preparations of organo-vermiculite with large interlayer space by hot solution and ball milling methods: A comparative study

The intercalation of alkylammonium ions into vermiculite (VMT) to improve the interior structure of VMT has evolved into a subject of tremendous interest. The Na⁺-exchanged vermiculite (Na-VMT) prepared from the VMT in Xinjiang area (China), served as a host for intercalation with cetyl-trimethylammonium (CTA⁺) to prepare organo-vermiculites (OVMTs) by a typical hot solution method (OVMT (H)) and a novel ball milling method (OVMT (M)) under the optimized conditions confirmed by orthogonal experimental designs. The two methods employed thermal energy and mechanical energy respectively to drive the CTA⁺ cations into the interlayer space of layers and to carry out the cation exchange reaction. From X-ray diffraction (XRD) patterns, scanning electron microscopy (SEM) images and thermogravimetric analysis (TGA) results, the Na-VMTs were structurally modified, and the OVMTs showed remarkably large interlayer spaces, in which alkyl chains built paraffin-type bilayer arrangements nearly perpendicular to silicate layers. However, hot solution and ball milling methods showed different behaviors. The interlayer distance of the OVMT (M) (4.283 nm) was larger than that of the OVMT (H) (4.052 nm), indicating that the tilting angle of alkyl chains in the former was larger than that in the latter. Additionally, the hot solution treatment retained the morphology of the layers and reduced the surface energy of the VMT, whereas the ball milling method caused layers to twist and led to high residual surface energy on the particles, as well as a higher content of organic compounds and lower thermal stability for the product.     

Intercalative redox polymerization and characterization of poly(n‐vinyl‐2‐pyrrolidinone) in the gallery of vermiculite: A novel inorganic–organic hybrid material

In this article we present the synthesis of poly(N‐vinyl‐2‐pyrrolidinone) (PNVP)–vermiculite hybrid material and its characterization by various spectroscopic techniques, X‐ray diffraction (XRD), and thermal analysis. The polymer was synthesized by intercalative redox polymerization of the monomer at 110°C, using copper (II) ion‐exchanged vermiculite. XRD analysis following intercalative polymerization indicates the presence of two prominent peaks with corresponding d (002) spacing of 14.3 (intercalated) and 9.9 (not intercalated) Å, suggesting the formation of a partially intercalated hybrid material. Electron spin resonance studies of the intercalated material show values of “g” different from that of the Cu (II)‐ion‐exchanged vermiculite, indicating that polymer formed in the gallery of vermiculite complexes with the unreacted Cu (II). Thermogravimetric analysis indicates the amount of polymer in the gallery spacing to be ≈20 mass %, which is confirmed by I₂ labeling of the PNVP in the nanocomposite, followed by UV spectroscopy. The IR absorption peaks corresponding to PNVP, along with the XRD and thermal analysis data confirms that the gallery expansion is due to the formation of a partially intercalated inorganic‐organic hybrid material. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1825–1830, 2000