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1.
以γ-聚谷氨酸(γ-PGA)和蒙脱土(MMT)为原料,采用溶液插层法制备γ-PGA/MMT复合材料.研究了γ-PGA分子量、插层时间和插层温度对插层效果的影响,并探讨了γ-PGA在MMT中的形态.实验结果显示,不同分子量的γ-PGA,均能对MMT实现插层;MMT的层间距随着插层时间的延长逐渐增大,在8 h后达到最大,随后略有下降;MMT的层间距随着插层温度的升高逐渐增大,在60℃时达到最大值,温度继续升高则有所下降;γ-PGA分子在MMT的片层间为α-螺旋构象,且呈单分子层排列.  相似文献   

2.
采用离子交换法,用溴化烯丙基三乙基铵对钠基蒙脱土进行改性制备了有机蒙脱土,再以甲基丙烯酸甲酯(MMA)为单体,过硫酸钾为引发剂,通过无皂乳液聚合制备聚甲基丙烯酸甲酯朦脱土(PMM-MMT)纳米复合材料。采用傅里叶变换红外(FTIR)、X-射线衍射(XRD)和扫描电镜(SEM)等手段对有机蒙脱土和复合材料的结构进行表征。结果表明:溴化烯丙基三乙基铵成功插层到蒙脱土层间,层间距由1.32nm增大到1.44nm;FTIR和XRD测试结果表明不同蒙脱土含量的PMMA/MMT纳米复合材料均具有剥离型结构;SEM测试结果表明PMMA/MMT纳米复合粒子的粒径随蒙脱土含量的增加而减小。  相似文献   

3.
季铵盐改性蒙脱土的微观结构与表面分形特征   总被引:4,自引:0,他引:4  
以两种双子季铵盐(MD,DMB)和一种单季铵盐(HTMAB)为有机改性剂,通过阳离子交换法对Na蒙脱土改性,制得季铵盐有机改性蒙脱土。采用N2吸附法、X射线衍射(XRD)及红外光谱分析(FT-IR)研究了季铵盐有机改性蒙脱土的微观结构及表面特征。结果表明,经MD,DMB及HTMAB改性后,蒙脱土BET比表面积及层间距均有所减小,这与传统长链单季铵盐的改性效果不同;有机改性后,季铵盐阳离子成功吸附于蒙脱土的层间,蒙脱土的微观结构发生了改变,形成微孔和介孔同时存在的二维交错多孔结构,表面由亲水性转变为疏水性,且改性蒙脱土分形维数D较原土有所减小,表明改性土孔隙分布更加均匀。  相似文献   

4.
采用熔融插层法制备了聚乙烯/马来酸酐接枝聚乙烯/蒙脱土(PE/PEMA/MMT)纳米复合材料,研究了不同质量分数的蒙脱土对聚乙烯力学性能、热稳定性能及对有机溶剂的阻隔性的影响,并用X射线衍射法对材料的微观结构进行了表征.结果表明,聚乙烯分子链已插层进入蒙脱土层间,材料的拉伸强度最大提高了13.5%,热分解温度有一定程度的提高,材料对有机溶剂的阻隔性也有所改善、  相似文献   

5.
插层剂与蒙脱石结构对蒙脱石插层改性的影响   总被引:1,自引:0,他引:1  
选用4种不同结构类型的插层剂对3种具有不同结构特性的蒙脱石(MMT)进行了有机化插层改性,采用X-射线衍射研究了插层剂与MMT的结构对不同MMT插层改性的影响。结果表明:带有双烷基链的插层剂的插层效果要远远优于单烷基分子链的插层剂,MMT层间距相比增大了2.65~3.67 nm。单烷基链插层剂较易进入MMT层间,层间距的变化受MMT本身的结构特性影响较小;而选用双烷基链插层剂时,MMT本身的结构特性对其层间距变化的影响较大,不规整的层间结构和较小的层间距限制了插层剂分子进入MMT层间。插层剂中含有的苄基对不同MMT层间距的影响表现出较大的差异性。  相似文献   

6.
A kind of slow release drug-loaded microspheres were prepared with gelatin, chitosan and montmorillonite(MMT) by an emulsification/chemical cross-linking method using glutaraldehyde as cross-linking agent and acyclovir as model drug. The microspheres were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM), respectively. The morphology, drug content, encapsulation efficiency and drug-release behavior were investigated with different MMT content...  相似文献   

7.
根据蒙脱土(MMT)特殊的片层结构,采用熔融插层法制备了HIPS/MMT及HIPS/OMMT复合材料,并用锥形量热仪对材料的燃烧性能进行测试。结果表明,材料中蒙脱土片层的取向影响材料的阻燃性;与竖直取向的HIPS/OMMT复合材料相比,水平取向的HIPS/OMMT复合材料有更低的热释放速率和质量损失速率,具有较高的阻燃性。用扫描电镜表征了不同取向材料燃烧后炭层的形貌,表明形成的炭层也具有横、竖取向。此现象解释了插层复合材料的取向影响材料的阻燃性,为聚合物/层状硅酸盐纳米复合材料阻燃机理的研究提供了依据。  相似文献   

8.
High pressure method was ased for the first time to produce rectorite clay (REC)/phenolic resin (PF) and organic rectorite clay (OREC) /phenolic resin and montmorillonite( MMT)lphenolic resin (PF) nanocomposites. The structure of the material phase was studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared ( FT- IR ) spectroscopy, thermogravimetric analysis ( TGA ), and atomic force microscopg" (AFM). The experimental results show that intercalated clay/resin nanocomposites could form under normal temperature and high pressure conditions by the intercalation of polymeric molecules rather than interlayer polymerization.  相似文献   

9.
为了提高以明胶为稳定剂分散聚合制备的聚丙烯酰胺“水包水”(W/W型PAM)乳液的絮凝性能,首先,采用阳离子单体甲基丙烯酰氧乙基三甲基氯化铵(methacrylatoethyl trimethyl ammonium chloride, DMC)对钠基蒙脱土(sodium-montmorillonite, Na-MMT)进行插层改性制备有机蒙脱土(organic montmorillonite, OMMT),通过X射线衍射(X-ray diffraction, XRD)测试得到插层改性后蒙脱土的层间距由1.25 nm增加至1.43 nm,说明DMC单体已经成功插层进入蒙脱土片层。然后,将OMMT引入以明胶为稳定剂的W/W型PAM乳液的体系中,以制备W/W型PAM-MMT乳液。通过透射电镜(transmission electron microscope, TEM)乳液微观形貌进行观察,得到乳液结构是由以蒙脱土颗粒为“交联点”的聚丙烯酰胺高分子网络和W/W型PAM乳液的混合体。研究了OMMT用量、明胶浓度、体系pH值以及阳离子单体DMC添加比例对合成W/W型PAM-MMT乳液性能的影响规律。结果显示:在适宜条件下合成的乳液均具有较好的储存稳定性和在水中的再分散性。乳液的表观黏度和絮凝性能都与OMMT和明胶用量呈正相关性;当pH值在明胶等电点(isoelectric point,IEP)时,得到的乳液的表观黏度最低,絮凝效果最好;随着DMC单体用量比例增大,乳液表观黏度减小,高岭土悬浮液的絮凝效果先增大后减小。  相似文献   

10.
通过反应挤出制备了高密度聚乙烯/聚酰胺6/蒙脱土(HDPE/PA6/MMT)复合材料,研究了MMT在HDPE/PA6共混物中的分散和分布情况,及其对共混物相态结构的影响。从XRD和TEM的结果中可以看出,有机化蒙脱土(OMMT)选择性地分布在PA6相内以及两相的界面上,钠基蒙脱土(Na+MMT)则主要分布在PA6相内;大部分OMMT得到较好的剥离或插层,而Na+MMT出现明显的团聚。FE—SEM分析结果表明,增大MMT的含量会导致PA6的相态尺寸变大,粒径分布变宽。流变分析结果表明,由于OMMT部分分布于两相界面处,从而增强了界面结合,对共混物起到了增容作用。  相似文献   

11.
用悬浮接枝法制备了接枝率为2 2%的聚丙烯接枝丙烯酸作为相容剂,用十六烷基三甲基溴化铵对钠基蒙脱土进行了有机化处理,使蒙脱土的层间距从1 2nm增加到了3 84nm。通过熔融插层法制备了插层型聚丙烯/蒙脱土纳米复合材料(Polypropylene/MontmorilloniteNanocomposites,PNC),复合材料中蒙脱土层间距比有机蒙脱土的层间距又有小幅度的增加。当蒙脱土含量为2%,相容剂用量为15%时的复合材料力学性能最好,缺口冲击强度和拉伸强度分别达到12 12kJ/m2和35 77MPa,分别比纯1PP增加了180%和4 3%,蒙脱土的加入起到了增韧和增强的双重作用。  相似文献   

12.
A low adsorption clay-resistant polycarboxylate superplasticizer (KN-PC) was synthesized using acrylic acid and isopentenol polyoxyethylene ether as the main reaction materials.The structural characterization and clay-resistant mechanism of the KN-PC were explored using Fourier transform infrared spectroscopy and X-ray diffraction,and the effect of the KN-PC on the performance of composite paste with various montmorillonite (MMT) contents was analyzed.Compared with ordinary polycarboxylate superplasticizer (PC),the KN-PC has a low sensitivity to the MMT.By the action of the MMT,the adsorption dosage of the KN-PC on the MMT is much smaller than that of the PC.  相似文献   

13.
Lignocellulose/montmorillonite (LNC/MMT) nanocomposites were prepared and characterized by FTIR and XRD. The adsorption of congo red (CR) on LNC/MMT nanocomposite was studied in detail. The effects of contact temperature, pH value of the dye solutions, contact time and concentration of dye solutions on the adsorption capacities of lignocellulose (LNC), montmorillonite (MMT) and the nanocomposite were investigated. The adsorption kinetics and isotherms and adsorption thermodynamics of the nanocomposite for CR were also studied. The results show that the adsorption capacity of LNC/MMT nanocomosite is higher than that of LNC and MMT. All the adsorption processes fit very well with the pseudo-second-order and the Langmuir equation. From thermodynamic studies, it is seen that the adsorption is spontaneous and endothermic.  相似文献   

14.
季铵盐改性蒙脱石的超结构及其抗菌性能   总被引:1,自引:0,他引:1  
为研究季铵盐改性对蒙脱石的结构及抗菌性能的影响,分别采用十八烷基三甲基氯化铵(OTAC)和双十八烷基二甲基氯化铵(DODAC)对蒙脱石进行插层改性,并分析了蒙脱石的d001层间距及抗菌性能随季铵盐用量变化的规律.蒙脱石的d001层间距先随季铵盐用量的增加而增大;当OTAC与蒙脱石的质量比超过35%或DODAC与蒙脱石的质量比超过15%时,其d001层间距开始略微下降,同时出现季铵盐以不同倾斜角排列的层间超结构现象.在水分散体系中,改性蒙脱石的抗菌性能先随季铵盐用量的增大而上升;当其出现超结构后,由于蒙脱石及季铵盐与细菌的接触几率受到限制,其抗菌性能开始急剧下降.在干燥条件下超结构对蒙脱石的抗菌性能影响甚微,经不同用量季铵盐改性的蒙脱石都具有极佳的抗霉菌性能.  相似文献   

15.
Both of quaternary ammonium and quaternary phosphonium salts of bis-hydroxyethyl terephthalate (BHET) were successfully synthesized and characterized by fourier transform infrared spectroscopy (FT-IR). These two kinds of salts were used to intercalate Na-MMT to yield two kinds of respective organo-modified MMTs. Basal spacing and thermal stability were investigated by using X-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. The experimental results show that, as compared with Na-MMT, basal spacings of both of MMTs modified by the quaternary phosphonium salt of BHET (BHETPP) and the quaternary ammonium salt of BHET (BHEA), increase from 12.4 Å to 19.7 Å and 31.3 Å, respec-tively. Thermal stability of BHETPP-modified MMT is much better than that of BHEA-modified MMT, i e, T onset of BHETPP-modified MMT is around 400 °C while T onset of BHEA-modified MMT is near 250 °C. Therefore, with en-larged basal spacing and excellent thermal stability, BHETPP-modified MMT is a promising organo-modified MMT which may be used to prepare polyethylene terephthalate/MMT nanocomposite with high thermal and mechanical performance.  相似文献   

16.
以甲基丙烯酸甲酯(MMA)、蒙脱土(MMT)以及乙醇胺为主要原料,采用原位氧化还原聚合的方法制备出一种聚合物/蒙脱土纳米复合材料。采用红外光谱(FT-IR)、粉末X-射线衍射(XRD)、扫描电子显微镜(SEM)、热重(TGA)等分析手段表征所制备的纳米复合材料的结构。通过原位氧化还原聚合方法成功制备了完全剥离型复合材料和部分插层结构型复合材料。结果表明,MMT的加入显著提高了复合材料的热稳^串性能。此外,还推测出纳米复合材料的形成机理。  相似文献   

17.
The effects of surface modification on montmorillonite (MMT) were illustrated in order to produce the composite material with premium properties. MMT was treated with two coupling agents: glutaraldehyde (GA) and 7-methacryloxy-propyl-trimethoxy silane (KH570). The effects of different coupling agents on MMT and protein interaction were investigated by XRD, FT-IR, TGA, UV-Vis, etc. The results of structure characterization indicated that KH570 modification could change the surface crystal structure of MMT. However, GA reacted with amino groups of Bovine serum albumin (BSA) and the ordered layer structures of MMT were not completely destroyed. Coupling agents could greatly increase the amounts of BSA intercalated and the effect of KH570 is better than that of GA. And, the optimum concentrations of KH570 and GA were 2% and 6%, respectively. The rate of weight loss increased by about 12% after MMT was pretreated with coupling agents. The possible reason is that coupling agent treatment makes the structure of MMT more accessible to protein absorption and helps to stabilize the protein structure. Moreover,the presence of coupling agents can reduce the direct chemical interaction between BSA and MMT, which results in increasing protein desorption.  相似文献   

18.
Montmorillonite supported titanium(Ti-MMT) or antimony catalyst(Sb-MMT) has been a hot area of research on preparing polyethylene terephthalate/montmorillonite(PET/MMT) nanocomposites by in situ polymerization. So removal of Ti or Sb from Ti-MMT or Sb-MMT is not expected during in situ polymerization. Studies on immobilization of Ti or Sb on Ti-MMT or Sb-MMT are seldom reported. In this work, a series of montmorillonite supported catalysts of titanium(Ti-MMT) or antimony(Sb-MMT) and cointercalated montmorillonite of titanium and antimony(Ti/Sb-MMT) were prepared by(1) the reaction of sodium bentonite suspension with intercalating solution containing titanium tetrachloride and/or antimony chloride, and(2) drying or calcinating the products at different temperature(100, 150, 240, 350 and 450 ℃). The physicochemical properties of these MMT supported catalysts were studied by X-ray diffraction(XRD), fourier transform infrared spectroscopy(FT-IR), inductively coupled plasma optical emission spectrometer(ICPOES), N 2 adsorption/desorption isotherms, UV-visible diffuse reflectance spectroscopy(UV-vis) and transmission electron microscopy(TEM). The immobile character of Ti or Sb on MMT supported catalysts was evaluated by a two-step method in deionized water or ethylene glycol. Several results were obtained, i e,(a) during the preparation, with an increase in drying or calcinating temperature, the amount of titanium and/or antimony species remained on these MMT supported catalysts decreased,(b) the experiments about immobile character of Ti or/and Sb showed that with an increase in drying or calcinating temperature, the immobilization of Ti and/or Sb species remained on these MMT supported catalysts increased gradually,(c) Ti-MMT calcinated at 450 ℃ had the biggest pore volume, which means Ti-MMT had the best adsorption application prospect.  相似文献   

19.
聚丙烯腈/蒙脱土纳米复合材料的制备与表征   总被引:1,自引:0,他引:1  
采用不同改性蒙脱土与丙烯腈单体原位聚合制得纳米复合材料,通过红外、XRD表征蒙脱土插层前后结构的变化,并用热重、差热分析产物的稳定性.X射线粉末衍射结果显示,改性后蒙脱土层间距被不同程度扩大,尤其是PAN/Na-MMT的(001)衍射峰已完全弥散,说明蒙脱土被剥离.差热、热重分析结果显示聚丙烯腈/蒙脱土纳米复合材料的热稳定性比纯聚丙烯腈有较大提高.  相似文献   

20.
为了提高聚丙烯酰胺水溶液的黏度及耐盐性能,将有机蒙脱土加入到聚合体系中,通过双水相聚合的方法制备出聚丙烯酰胺/有机蒙脱土(PAM/MMT)纳米复合材料.采用正交实验方法分析讨论了不同的有机蒙脱土(MMT)加入量、引发剂加入量、分散剂聚乙二醇(PEG)浓度、单体浓度等因素对PAM/MMT纳米复合材料特性粘数的影响,从中优化出最佳反应条件.采用红外色谱(FTIR)及x 射线衍射仪(XRD)对PAM/MMT纳米复合材料的化学组成及有机蒙脱土形态进行了分析,结果表明,双水相聚合方法可以制备出预期的PAM/MMT纳米复合材料,所得产品水溶液黏度高、耐盐性能好,产品作为驱油剂可以产生良好的效果.  相似文献   

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