麦羟硅钠石的制备与表征EI北大核心CSCD

采用水热法在SiO2-NaOH-Na2CO3-H2O体系中制备了单一晶相麦羟硅钠石(magadiite),研究了晶化时间、晶化温度和初始物料比对制备的影响,并对样品的结构进行表征。结果表明,在初始物料摩尔比为n(SiO2):n(NaOH+Na2CO3):n(H2O)=3:1:100,晶化温度和时间分别为170℃和24h或n(SiO2):n(NaOH+Na2CO3):n(H2O)=5:1:100,晶化温度和时间分别为160℃和36h以及n(SiO2):n(NaOH+Na2CO3):n(H2O)=7:1:100,晶化温度和时间分别为150℃和48h条件下,均可制备单一晶相麦羟硅钠石,H2O和SiO2含量、晶化时间和晶化温度的提高均不利于麦羟硅钠石的结晶。所制备的麦羟硅钠石形态为玫瑰花形且其热稳定性在250℃以下。     

水羟硅钠石的制备与表征

水羟硅钠石（kenyaite）以其良好的离子交换性、吸附性和热稳定性而被广泛应用于催化和吸附等领域。本文以高纯度且价格低廉的沉淀白炭黑为硅源、以碳酸钠（分析纯）和氢氧化钠（分析纯）为碱源,水热法制备了高纯度的单一晶相的水羟硅钠石,考察了反应时间和反应温度对制备的影响。利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）、红外光谱仪（IR）、X射线荧光光谱仪（XRF）和同步热分析仪等对样品进行了测试表征。实验结果表明,温度是影响kenyaite制备的主要因素,单一晶相水羟硅钠石的最佳晶化合成条件为晶化温度为180℃,晶化时间为24h,所制备的水羟硅钠石形态为玫瑰花形且其热稳定性在350℃以下。     

聚合物/勃姆石纳米复合材料研究进展

综述国内外聚合物/勃姆石纳米复合材料研究进展.在总结勃姆石溶胶的制备及表面改性方法的基础上,分析了聚合物/勃姆石纳米复合材料的制备方法与性能,并对其工业化应用研究进行了展望.     

聚合物/SiO_2纳米复合材料的研究进展

针对当前对聚合物/SiO2纳米复合材料的研究热点,结合近十年国内外的研究成果,简要介绍了纳米SiO2表面改性方法、复合材料的制备方法及其主要性能,系统地阐述了纳米SiO2对聚合物性能包括力学性能、热性能、摩擦性能、阻燃性能等的作用机制及规律。     

伊利石硅渣蒸汽辅助合成麦羟硅钠石及其对Cu2+的吸附研究

以伊利石硅渣为原料,采用蒸汽辅助转化法(SAC)合成了高产率、高结晶度的纯相麦羟硅钠石(Magadiite)。采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)考察了钠硅比(n(Na₂O)/n(SiO₂))、晶化温度和晶化时间对合成样品结构及形貌的影响。结果表明,该体系的初步优化合成条件为钠硅比0.15,晶化温度170 ℃,晶化时间16 h,样品形貌为玫瑰花形(尺寸约12 μm)。对合成的Magadiite进行Cu²⁺吸附性能测试,探究了吸附剂用量、pH值、吸附时间和Cu²⁺初始浓度对吸附效果的影响。在吸附剂用量为2 g/L,pH值为5,吸附时间为30 min时,Magadiite对Cu²⁺的最大吸附量为25.99 mg/g。     

麦羟硅钠石在环氧涂料中防腐性能的研究

首先采用双子表面活性剂（ GS）对麦羟硅钠石（ MAG）进行有机化改性,然后负载苯并三氮唑（ BTA）,制备了一种负载 BTA的 MAG新型填料（ BGM）通过红外光谱和扫描电镜对其结构和形貌进行了表征,然后将 BGM添加到环氧树脂中考察了涂层,性能。结果表明： GS对 MAG进行了有机化改性并成功负载了 BTA,同时 BGM以剥离状片层结构存在;添加 BGM填料的涂层表面光滑平整,微孔大大降低;极化曲线测试表明添加 BGM的涂层腐蚀电流密度和腐蚀电压最小,分别为 2. 42×10-9 A/cm²和-1. 157 V;电化学阻抗谱拟合电路后的 Rct和 Rc分别为 4. 14×106 Ω·cm²和 3. 00×105 Ω·cm²,R_ct与 R_c之和最大,说明添加 BGM后涂层的耐腐蚀性最好;水接触角测试表明添加 BGM的涂层的接触,角最大为 89°,说明涂层具有较好的疏水性,从而提高了涂层的防腐性能。     

氨基功能化铝麦羟硅钠石吸附Hg2+性能研究

以水热合成的铝麦羟硅钠石（简称AlMag）为基体,以氨丙基三乙氧基硅烷为功能化试剂,制备氨基功能化的新型吸附剂材料AlMag-NH₂,研究氨基改性过程对材料结构的影响及其对水溶液中Hg²⁺的吸附效果。表征结果显示,氨基官能团成功嫁接于AlMag基体上,功能化的AlMag-NH₂由初始的玫瑰花苞形貌变为片层状形貌,层间距和平均孔径增大,比表面积略微减小,pH_PZC升高。优化吸附实验条件,当溶液pH=5.0、吸附时间为360 min、Hg²⁺初始质量浓度为10 mg/L时,AlMag-NH₂的去除率达到88.82%,是相同条件下AlMag去除率的2.4倍。AlMag-NH₂的Hg²⁺饱和吸附量为20.62 mg/g,吸附过程符合准二级动力学和Langmuir模型,该过程主要为化学吸附。     

层状硅酸盐麦羟硅钠石转晶制备丝光沸石

以二乙醇胺为模板剂,将麦羟硅钠石转晶制备出丝光沸石。分别采用X射线粉末衍射、红外光谱和扫描电镜对所合成的样品进行了表征。实验结果表明,制备出的丝光沸石为纯相,结晶度好,晶体形貌为棱柱型,耐酸性好,在6 mol/L 盐酸中搅拌3 h后仍能保持结构的完整性。实验分别从碱度、反应时间两个方面考察了反应因素对转晶的影响,确定了合成的最佳配比。碱度过高麦羟硅钠石会全部转晶成方沸石,而碱度过低会有部分麦羟硅钠石没有转晶;当反应时间为24 h时,会有部分麦羟硅钠石没有转晶成丝光沸石,而当反应时间延长到7 d,产物为方沸石和NaP沸石。     

聚合物基纳米复合材料的研究进展

首先对聚合物基纳米复合材料进行了简单的归类,然后按分类介绍了各种聚合物基纳米复合材料的研究情况,对复合材料的制备方法、结构与性能特征及潜在的应用前景进行了扼要的总结。     

纳米改性聚合物材料研究进展

综述了纳米改性聚合物材料的研究进展,包括纳米粒子的结构与性质,纳米粒子的表面改性,纳米粒子对聚合物的改性机理和方法及纳米技术在高分子材料领域中的应用。     

聚合物/蒙脱土纳米复合材料的研究进展

聚合物/蒙脱土纳米复合材料是近十年来研究最为广泛的复合材料之一,优异的热力学性能,独特的气 液阻隔性及阻燃性赋予它广泛的工业应用前景。本文就该复合材料在蒙脱土的有机改性处理、制备、制备条件对性能的影响、表征方法及手段、材料性能特征及应用等方面作一些简单总结。     

Mechanical reinforcement in magadiite/styrene‐butadiene rubber composites

This work investigates mechanical properties of styrene‐butadiene rubber (SBR) composites incorporating magadiite (MGD), a synthetic layered silicate (Na₂Si₁₄O₂₉·9H₂O) with surface chemistry similar to precipitated silica used in tire tread formulations. Treatment with cetyltrimethylammonium (CTA⁺) expands the MGD layers and makes the interlayer face surfaces accessible to sulfur‐functional silane TESPT (Si69) and SBR, primarily during batch mixing. DMA and tensile testing of cured CMGD/SBR composites show that CTA‐treated MGD (CMGD) provides substantially higher levels of mechanical reinforcement than equivalent amounts of silica. However, CMGD/SBR composites exhibit larger loss tangent values above T_g, probably due to lower SBR‐SBR crosslink density resulting from interlayer trapping of sulfur released by Si69 during vulcanization. DMA and tensile testing also demonstrate Si69′s critical role in forming MGD‐SBR graft sites essential to mechanical reinforcement. Replacing silica with CMGD reduces composite weight without sacrificing tensile modulus, suggesting that use of CMGD in tire rubber formulations could improve vehicle energy efficiency. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44763.     

聚苯胺／无机纳米复合材料的研究进展

聚苯胺/无机纳米复合材料是一种新型的功能材料.综述了聚苯胺,无机纳米复合材料在制备方法,表征手段、性能和应用等方面的研究进展,并展望了聚苯胺,无机纳米复合材料今后的研究方向和应用前景.     

纳米纤维素及其聚合物纳米复合材料的研究进展

纳米纤维素（nanocellulose,NC）是一种具有优异力学性能、质轻、高比表面积、可再生、可生物降解等特性的新型纳米材料,纳米纤维素与聚合物结合得到的复合材料被视为新一代生物质基纳米复合材料。文章首先概述了微纤化纤维素（MFC）、纳米纤维素晶体（NCC）和细菌纳米纤维素（BC）3种主要纳米纤维素的特性及其主要的制备方法,并对其制备过程中存在的问题进行分析。其次,文章简述了纳米纤维素在亲水性聚合物（淀粉、聚乙烯醇、水性聚氨酯等）和非亲水性聚合物（聚乳酸、聚己内酯、聚羟基烷酸酯和环氧树脂等）纳米复合材料方面的研究进展。最后,指出纳米纤维素在绿色工业化生产过程中还需解决生产成本、分离技术、能耗和环境污染等问题。此外,提高纳米纤维素与聚合物之间的界面相容性,开发以纳米纤维素为主体成分的新型纳米复合材料是今后发展的一个重要方向。     

Tensile modulus of polymer/CNT nanocomposites containing networked and dispersed nanoparticles

The properties of three‐dimensional networks of nanoparticles in polymer/carbon nanotubes (CNT) nanocomposites (PCNT) are particularly interesting from fundamental and application views. In this article, a new model is suggested for predicting the tensile modulus of PCNT using the Ouali and Paul models. The Ouali model considers the network of CNT in a polymer matrix, while the Paul model predicts the tensile modulus of samples containing dispersed nanoparticles. The predictions of the suggested approach are compared with experimental data from several samples. Also, the roles of the main parameters in the tensile modulus of PCNT are evaluated. The predictions agree with the experimental results at different filler concentrations. The roles of these parameters on the tensile modulus of PCNT are discussed based on the properties of CNT networks. © 2017 American Institute of Chemical Engineers AIChE J, 63: 220–225, 2018     

Polyethylene/aluminum nanocomposites: Improvement of dielectric strength by nanoparticle surface modification

The effect of the surface modification with a silane coupling agent (octyl‐trimethoxysilane) of aluminum (Al) nanoparticles on the dielectric breakdown behaviors of polyethylene (PE)/Al nanocomposites was investigated in comparison of the influence of the improvement of the interfacial adhesion between Al nanoparticles and PE using a compatibilizer (maleic anhydride grafted polyethylene). It was found that when compared with the other modification approaches, the surface‐treated Al nanofiller with the silane coupling agent makes it possible for the PE/Al nanocomposites to still keep the relatively higher breakdown strength even in the higher Al loading level above 14 vol %, which can be understood in terms of the better interfacial adhesion between the surface‐treated particle dispersion and the matrix. The combined effects of the Al nanoparticles on the different factors which influence the dielectric breakdown processes in polymer matrix such as microstructure, conductivity, and crystallinity of the nanocomposites were discussed in detail. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

粘土橡胶纳米复合材料研究进展

简要概述了粘土的有机改性机理、橡胶/粘土纳米复合材料的制备方法、结构与表征和橡胶/粘土纳米复合材料的研究进展.     

聚合物／凹凸棒纳米复合材料的进展状况

综述了当前聚合物／凹凸棒纳米复合材料研究进展状况。展望了凹凸棒／聚合物复合材料应用前景,并分析了以后需要深八研究的方向。     

Improved properties of highly oriented graphene/polymer nanocomposites

A kind of molecular‐level dispersed and highly oriented graphene monolayer nanocomposite film was successfully obtained by in situ reduction of phenyl isocyanate functionalized graphite oxide (RPIGO) in N,N‐dimethylformamide in the presence of polystyrene (PS). Atomic force microscopy and transmission electron microscopy results show that the RPIGO monolayers were not only homogeneously intercalated into the PS matrix but also arranged parallel to the surface of the nanocomposite films. Because of the efficient interaction between the graphene monolayers and PS matrix, the mechanical properties of the graphene‐based nanocomposite films improved significantly. Compared with the pure PS film, a 28.4% increase in the Young's modulus and a 27.8% improvement in the tensile strength of the RPIGO–PS nanocomposites films were obtained with the addition of only 0.5 wt % graphite oxide. The glass‐transition temperature and onset degradation temperature of PS also increased from 96.6 and 427°C to 103.2 and 439°C, respectively. The improvement of the properties was mainly due to the large lateral thickness ratio and the high orientation of graphene monolayers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The role of interlayer grafting on the mechanical properties of magadiite/styrene‐butadiene rubber composites

This work examines the mechanisms by which magadiite (MGD), a synthetic layered silicate, acts as an active filler to provide high levels of mechanical reinforcement in styrene‐butadiene rubber (SBR) composites. Cetyltrimethylammonium (CTA⁺) expands the MGD layer spacing and promotes intercalation of SBR and silane coupling agent (Si69); the resulting CMGD/SBR composites have greater tensile moduli than comparable silica/SBR composites. CMGD was reacted in solution with Si69 (or MPTES) to prepare “pre‐grafted” MGD with varying levels of interlayer silane functionalization (SMGD). If the silane graft density is relatively low, the resulting SMGD/SBR composite has mechanical properties comparable to CMGD composites prepared with Si69 added during batch mixing. However, SMGD with high silane graft density does not permit SBR intercalation and produces composites with inferior mechanical properties, demonstrating the necessity of silane‐mediated interlayer grafting. Omitting Si69 from the formulation dramatically reduces the level of mechanical reinforcement as measured by DMA and tensile testing. Adding extra bulk sulfur (to replace sulfur omitted with Si69) does not produce composites with mechanical properties comparable to CMGD/SBR or SMGD/SBR prepared with Si69. This work demonstrates that silane‐mediated SBR‐MGD grafts within the MGD interlayer space are essential for achieving high levels of mechanical reinforcement in MGD/SBR composites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45025.