PMMA/MCM-41复合粒子对环氧树脂复合材料性能的影响

采用气相法先将聚甲基丙烯酸甲酯(PMMA)引入纳米介孔分子筛MCM-41的一维孔道内,制备出PM-MA/MCM-41复合粒子,再与环氧树脂(EP)共混,研究了PMMA/MCM-41复合粒子对EP/(PMMA/MCM-41)复合材料拉伸性能的影响。结果表明,PMMA分子链引入到MCM-41的孔道内,并且孔口处的PMMA与EP产生了较强的界面相互作用,增加了两者的相容性。PMMA/MCM-41复合粒子使EP的拉伸强度、拉伸弹性模量、断裂伸长率均有所提高。     

环氧树脂/纳米介孔分子筛复合材料的制备及性能研究

通过溶液共混法制备出环氧树脂（EP）／纳米介孔分子筛MCM-41（with template）（以下简称MCM-41）复合材料。研究了不同的MCM-41粒子含量对其在EP中的分散性和EP／MCM-41复合材料拉伸性能的影响。结果表明,这种具有独特的有机-无机复合结构的MCM-41直接用作填料时,能与EP形成新型网络复合结构,当MCM-41粒子的用量为1．5～2．5份时,它能均匀地分散在EP基体中,有效地提高EP／MCM-41复合材料的拉伸性能。     

介孔MCM-41对聚丙烯力学性能的影响

将纳米介孔MCM-41配制成悬浮液,采用熔融共混方法将其与聚丙烯共混,制备出综合力学性能较好的PP/MCM-41复合材料.透射电子显微镜(TEM)观测结果显示,MCM-41在悬浮液中呈纳米尺寸分散,无团聚现象;力学测试结果显示,当MCM-41的添加量为0.5%(质量分数)时,复合材料的拉伸、冲击、弯曲综合力学均较纯PP有所提高.     

MCM-41-HY介孔-微孔复合分子筛的水热合成

以微孔分子筛HY浆液为母液,合成介孔-微孔复合分子筛MCM-41-HY。通过XRD、NH_3-TPD和N_2吸附-脱附等手段对复合材料进行了表征,并对复合分子筛的水热稳定性进行了考察。结果表明,复合分子筛MCM-41-HY具有中孔分子筛MCM-41和微孔HY型沸石的特点,并且与纯MCM-41分子筛相比,复合分子筛的酸强度明显增强,水热稳定性提高。     

介孑LMCM-41对聚丙烯力学性能的影响

将纳米介孔MCM-41配制成悬浮液,采用熔融共混方法将其与聚丙烯共混,制备出综合力学性能较好的PP／MCM-41复合材料。透射电子显微镜（TEM）观测结果显示,MCM-41在悬浮液中呈纳米尺寸分散,无团聚现象;力学测试结果显示,当MCM-41的添加量为0．5％（质量分数）时,复合材料的拉伸、冲击、弯曲综合力学均较纯PP有所提高。     

新型高水热稳定性MOR/MCM-41复合分子筛的合成

以丝光沸石分子筛为硅铝源,通过碱液处理和表面活性剂的自组装作用,水热条件下合成了MOR/MCM-41复合分子筛。通过XRD、SEM、TEM、N2吸附/脱附和水热稳定性处理等手段对合成的复合材料进行了表征。结果表明,复合材料不仅保留了原丝光沸石晶体的规则形貌,同时兼具微孔分子筛MOR和介孔分子筛MCM-41的特征,且介孔(20~30 nm)在微孔分子筛中较均匀地分布。水热处理测试结果表明,MOR/MCM-41复合分子筛具有较高的水热稳定性,水热处理100 h后介孔结构依然存在。     

硅基纳米材料结合阿司匹林的缓释作用研究

本文在碱性条件下,硅酸钠作为硅源,十六烷基三甲基溴化铵(CTAB)作为结构模板剂,利用水合晶化法合成了纯硅源的MCM-41介孔分子筛.采用浸渍法将阿司匹林组装在MCM-41六方形孔道中,制备出新型载药Aspirin/MCM-41复合物。采用X射线粉末衍射(XRD)和傅里叶红外光谱(FT-IR)表征手段对合成的新型功能化介孔材料进行表征。MCM-41分子筛与阿司匹林的相互作用为研发以MCM-41分子筛为载体的载药体系提供了理论依据。     

CeO2纳米纤维合成表征及催化降解甲基紫染料

水热法合成不同硅铈比Ce-MCM-41 介孔分子筛,用NaOH溶解脱除MCM-41介孔分子筛模板得到铈氧化物。采用 XRD、SEM、TEM、N2吸附-脱附等手段对其结构进行表征。结果显示,当n（Si/Ce）=1.0:1.0时,制备CeO2纳米纤维直径4nm,纤维长度500nm左右,比表面积528.0 m2.g-1,具有类似模板介孔分子筛MCM-41规则有序介孔形貌。将所制备CeO2纳米纤维用于催化过氧化氢氧化分解质量浓度为40mg/L甲基紫染料废水,经 45min 反应后甲基紫水溶液脱色率达80.0% 。     

环氧/聚二甲基硅氧烷/MCM-41超疏水涂层的制备与性能研究

针对常规超疏水涂层制备工艺繁琐等问题，以介孔SiO₂纳米颗粒(MCM-41)为填料和载体，聚二甲基硅氧烷(PDMS)为低表面能改性剂，环氧树脂及其固化剂为成膜物，采用喷涂法制备了超疏水涂层。通过场发射扫描电子显微镜、共聚焦显微镜、接触角测量仪、拉伸试验机对其表面形貌、结构、疏水性及附着力进行表征。重点考察了PDMS改性的MCM-41(MCM-41/PDMS)和树脂基体质量比对涂层性能的影响。结果表明：当MCM-41/PDMS质量分数为55%，可以得到涂层疏水性(接触角150°，滚动角9°)和附着力(7.33 MPa)的最佳匹配，涂层经过胶带剥离300次和磨损150周期后，水接触角仍大于150°。     

EDA-GO/CPE/PS纳米复合材料的制备及性能研究

选取氯化聚乙烯(CPE)弹性体为增韧剂,乙二胺接枝氧化石墨烯(EDA-GO)为纳米填料,经熔融共混法制备了CPE/聚苯乙烯树脂(PS)和EDA-GO/CPE/PS纳米复合材料。采用红外光谱、拉伸测试、冲击测试和熔融指数测试方法研究了EDA-GO的表面结构,复合材料的拉伸性能、冲击性能和熔融流动性能。结果表明,乙二胺(EDA)已成功接枝于氧化石墨烯(GO)的表面上;在CPE/PS复合材料中,材料的拉伸强度和冲击强度的变化规律与一般弹性体增韧塑料的规律一致;在EDA-GO/CPE/PS纳米复合材料中,随着EDA-GO含量的增加其拉伸强度、冲击强度、断裂伸长率和弹性模量都有先上升后下降的趋势,当EDA-GO质量分数为0.5%时,拉伸强度达最大值,较CPE/PS复合材料提高了38%,较纯PS提高了61%;在EDA-GO质量分数为0.75%时,其冲击强度和弹性模量最大,比CPE/PS复合材料冲击强度和弹性模量分别提高了18%和41%。因此,当EDA-GO的质量分数在0.5%~0.75%之间时,复合材料的综合力学性能最好。随着EDA-GO的加入,纳米复合材料的熔融指数先下降后上升。     

Effect of nanosized mesoporous MCM-41 (with template) material on properties of natural rubber nanocomposites

Abstract

Mesoporous mobil composition of matter 41 (MCM-41) (with template) was used directly as a new filler for naural rubber (NR). Inside the pore chanels, and on the outer surface of the MCM-41 particle, were cationic surfactant CTAB and Pluronic F₁₂₇ (molecular weight = 11 500) mixture. Results showed that the tensile properties and the thermal stability of NR/mesoporous MCM-41 (with template) nanocomposite were improved at low filler loading as compared with those of NR compound. Scanning electron microscopy observations revealed that enhancement of the interface was obtained by adding MCM-41 (with template).     

Effect of cationic template on the adsorption of aromatic compounds in MCM-41

The effect of cationic template on the adsorption of aromatic compounds in MCM-41 was investigated in the present work. Various MCM-41 samples were prepared through controlling template removal during the synthesis of MCM-41 materials in which cationic surfactant was used as a template. The properties of synthesized samples were characterized with X-ray diffraction (XRD), nitrogen adsorption, FTIR and thermogravimetric analysis etc. The adsorption equilibriums of toluene, cumene and water on MCM-41 samples were measured using a digital microbalance. Compared with parent MCM-41 with template removed completely (denoted as MCM-41), the samples with template partially removed (denoted as C-MCM-41) exhibited moderate adsorption capacity for aromatic compounds. However, the adsorption equilibrium of water showed that the hydrophobicity on the surface of C-MCM-41 was significantly enhanced. The combination of moderate adsorption capacity for aromatics and hydrophobicity for water is desirable for the applications including removal of VOCs. It was found that the adsorption behaviors of aromatic compounds and water in various MCM-41 samples were governed by both porosity and cationic spots generated by cationic templates; and the former played a more important role than the latter when aromatics were adsorbed. The porosity and cation density of the MCM-41 material can be tailored by controlling the removal of the cationic template from the pore structure. The influence of template extraction methods on the structure and adsorption properties of MCM-41 materials has also been addressed.     

Study on performance of composite polymer films doped with modified molecular sieve for lithium-ion batteries

To improve the tensile strength and ionic conductivity of composite polymer films for lithium-ion batteries, molecular sieves of MCM-41 modified with sulfated zirconia (SO₄²⁻/ZrO₂, SZ), denoted as MCM-41/SZ, were doped into a poly(vinylidene fluoride) (PVdF) matrix to fabricate MCM-41/SZ composite polymer films, denoted as MCM-41/SZ films. Examination by transmission electron microscope (TEM) shows that modified molecular sieves have lower aggregation and a more porous structure. Tensile strength tests were carried out to investigate the mechanical performance of MCM-41/SZ films, and then the electrochemical performance of batteries with MCM-41/SZ films as separators was tested. The results show that the tensile strength (σ_t) of MCM-41/SZ film was up to 7.8 MPa; the ionic conductivity of MCM-41/SZ film was close to 10⁻³ S cm⁻¹ at room temperature; and the coulombic efficiency of the assembled lithium-ion battery was 92% at the first cycle and reached as high as 99.99% after the 20th cycle. Meanwhile, the charge-discharge voltage plateau of the lithium-ion battery presented a stable state. Therefore, MCM-41/SZ films are a good choice as separators for lithium-ion batteries due to their high tensile strength and ionic conductivity.     

Pd-β/MCM-41复合分子筛加氢裂解废食用油性能研究

以碱处理β沸石作为硅铝源,以CTAB为模板剂,合成了β/MCM-41介孔-微孔复合分子筛,以其为载体制备Pd-β/MCM-41复合分子筛催化剂,利用XRD、N₂吸附-脱附、NH₃-TPD和XRF等技术对其进行了表征,并与γ-Al₂O₃、USY、ZSM-5等载体制备的催化剂比较了废食用油加氢裂解活性。结果表明：β/MCM-41复合分子筛同时具备β沸石和MCM-41分子筛的结构,β/MCM-41为载体时,Pd-β/MCM-41催化剂具有适宜的中强酸性中心,适宜的孔道分布结构,催化剂加氢裂解废食用油的活性最高。此外还考察了催化剂制备条件对废食用油加氢裂解反应的影响,结果表明：采用离子交换法制备负载量2%的Pd-β/MCM-41复合分子筛催化剂、焙烧温度为500 ℃时,催化剂对废食用油加氢裂解的效果最好。此时,原料油的转化率可以达到85.9%,生物汽油的收率可以达到16.4%,生物柴油的收率达到17.8%,且此催化剂水热稳定性较好,再生性能良好,工业化应用前景较好。     

Synthesis of V-MCM-41 by template-ion exchange method and its catalytic properties in propane oxidative dehydrogenation

Vanadium has been introduced to MCM-41 without collapse of the mesoporous structure by exchanging VO²+ ions in the aqueous solution with the template cations in the uncalcined MCM-41. This template-ion exchange (TIE) method provides tetrahedrally coordinated vanadyl species dispersed in the channel of MCM-41. Such synthesized V-MCM-41 shows higher catalytic activity in the oxidative dehydrogenation of propane than that prepared by direct hydrothermal method.     

Direct synthesis of bi-modal porous structure MCM-41 and its application in CO2 capturing through amine-grafting

A bi-modal porous structure MCM-41 (BPS-MCM-41) was synthesized and functionalized by 3-[2-(2-Aminoethylamino)ethylamino]propyltrimethoxysilane (TRI); also, its performance in amine grafting and CO₂ capturing was compared with that of pore-expanded MCM-41 [1]. To create larger pores beside the mesoporous structure of MCM-41, carbon black nanoparticles were used as the solid template. Characterizing the BPS-MCM-41 using the BET and BJH techniques resulted in the surface reduction of 29.3 percent and volume increase of 68.46 percent. The pore size distribution showed two peaks: a narrow peak at 2.24 nm diameter, which belonged to micelles, and a wide one at about 50 nm due to the presence of used nanoparticles. The functionalization confirmed that BPS-MCM-41 is capable of accommodating a large quantity of amine groups. The CO₂ adsorption measurement indicated that internal volume of the adsorbent was a critical factor affecting the adsorption capacity of the amine grafted adsorbents.     

模板剂碳链长度对MCM-41晶体结构的影响

The mesoporous molecular sieve （MCM）-41 using ionic liquid as template has been prepared. The typical template of ionic liquid was [C16mim]X. In this article, the use of 1-alkyl-3-methylimidazolium （[Cnmim]Br, where n= 12,14,16,18,20） salts as templates in the synthesis of MCM-41 is reported. The results showed that the synthesized MCM-41 had uniform pore diameter, high surface area and stable framework. The largest surface area of MCM-41 was the one prepared with [C14mim]Br as template. When using [C18min]Br as template, the narrowest pore distribution sample was obtained and the effect of surface tension of template solution to MCM-41 was first discussed.     

含L沸石次级结构单元的介孔分子筛的合成

以极低浓度n(CTAB)∶n(SiO₂)=0.06的阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）为模板,以具有L沸石次级结构单元的溶胶为前驱体,在碱性条件下合成介孔分子筛L-MCM-41。样品的XRD、FT-IR、N₂吸附脱附和NH₃-TPD等表征结果表明,合成出的介孔分子筛是孔壁含有L沸石次级结构单元的六方晶相结构,该介孔分子筛的孔壁厚于常规水热方法合成的MCM-41的孔壁,具有较高的水热稳定性和较强的酸性。