广丰蒙脱土的有机改性、结构表征及应用研究

以十六烷基三甲基溴化铵对广丰蒙脱土进行有机改性,以红外光谱、XRD、TG-DSC等手段对其结构进行了表征,研究发现有机改性后蒙脱土晶层间距达到2.250nm。将制备的有机蒙脱土添加于环氧树脂中,在含量为5%时环氧树脂的冲击强度和断裂强度明显提高,而添加3%可使环氧树脂热变形温度提高6.1℃。     

聚丙烯／蒙脱土纳米复合材料的制备与性能

用烷基季铵盐对钠基蒙脱土进行有机化处理,使其成为有机蒙脱土。X射线衍射（XRD）表明有机阳离子已同钠离子发生离子交换作用,导致层间距扩大。用熔融插层法制备聚丙烯／蒙脱土纳米复合材料,测试了力学性能。通过XRD、DSC等手段研究了其结构与结晶行为,并与聚丙烯进行了对比。实验表明,通过熔融插层可使聚丙烯插层于蒙脱土片层之中,且所得聚合物的冲击强度有所提高。     

蒙脱石复合贮热材料的制备

蒙脱石是一种层状硅酸盐矿物。本文利用季铵盐与蒙脱石进行阳离子交换反应合成有机蒙脱石 ,然后 ,采用熔融法制备新戊二醇 (NPG)与蒙脱石的复合贮热材料 ,并用 X射线衍射、IR和 DSC等手段研究了复合材料的结构和性能。     

Direct methanol fuel cell (DMFC) based on PVA/MMT composite polymer membranes

A novel composite polymer electrolyte membrane composed of a PVA polymer host and montmorillonite (MMT) ceramic fillers (2–20 wt.%), was prepared by a solution casting method. The characteristic properties of the PVA/MMT composite polymer membrane were investigated using thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), and micro-Raman spectroscopy, and the AC impedance method. The PVA/MMT composite polymer membrane showed good thermal and mechanical properties and high ionic conductivity. The highest ionic conductivity of the PVA/10 wt.%MMT composite polymer membrane was 0.0368 S cm⁻¹ at 30 °C. The methanol permeability (P) values were 3–4 × 10⁻⁶ cm² s⁻¹, which was lower than that of Nafion 117 membrane of 5.8 × 10⁻⁶ cm² s⁻¹. It was revealed that the addition of MMT fillers into the PVA matrix could markedly improve the electrochemical properties of the PVA/MMT composite membranes; which can be accomplished by a simple blend method. The maximum peak power density of the DMFC with the PtRu anode based on Ti-mesh in a 2 M H₂SO₄ + 2 M CH₃OH solution was 6.77 mW cm⁻² at ambient pressure and temperature. As a result, the PVA/MMT composite polymer appears to be a good candidate for the DMFC applications.     

Water remediation by micelle-clay system: case study for tetracycline and sulfonamide antibiotics

Removal of tetracycline and sulfonamide antibiotics from water by micelles pre-adsorbed on montmorillonite was studied. Micelles of benzyldimethylhexadecylammonium (BDMHDA) were used. Batch experiments demonstrated that the micelle-clay complexes (1% w/w) removed 96-99.9% of antibiotics from their water solutions containing from 5 to 50 mg/L of pharmaceuticals. Column filters (25 cm) made of a mixture of quartz sand and BDMHDA micelle-clay complex at 100:1 w/w ratio removed 94-99.9% of above pharmaceuticals from initial solutions containing 10mg/L and 89% of sulfamethizole from an initial solution containing 10 microg/L of this antibiotic. These filters were also very efficient in the removal of antibiotics in the presence of dissolved soil organic matter removing 89-99% of tetracycline and sulfamethizol from initial solutions containing 10 mg/L of antibiotic in the presence of 8 mg/L of humic acid, or 9 mg/L of fulvic acid. These data indicate that micelle-clay complexes are very efficient for water purification from tetracycline and sulfonamide antibiotics.     

Effect of hydroxy-aluminium species on the sorption and interlayering of albumin onto montmorillonite

Proteins interact with soluble OH–Al species or Al precipitation products forming organo-mineral complexes with different chemical and physico-chemical properties. We studied the effect of pH, cation saturating the clays, presence of OH–Al species and order of component (OH–Al species, albumin and montmorillonite) addition on the amounts of proteinic molecules adsorbed on montmorillonite and the possible interlayering of OH–Al–protein complexes. Albumin molecules were very well intercalated into the interlayers of Na-montmorillonites, but very poor or no intercalation was observed for Mg-saturated montmorillonite and for an Al(OH)_x-montmorillonite (chlorite-like) complex.We have found that the amount of albumin sorbed on the external and interlamellar spaces of montmorillonite in the presence of OH–Al species was influenced by the sequence of addition of albumin (Alb), OH–Al species (Al) and montmorillonite (Mt). Complexes were prepared by mixing: (i) Al+Mt before Alb; (ii) Al+Alb before Mt; and (iii) Alb+Mt before Al. When albumin was added to montmorillonite before OH–Al species (Alb+Mt before Al complexes) proteinic molecules were able to penetrate more easily into the interlayers of montmorillonite. On the contrary, when OH–Al species were initially added to the clay (Al+Mt before Alb complexes), they were previously interlayered and consequently prevented the intercalation of the proteinic molecules. Finally, when OH–Al species and proteins were added to the clay as a mixture (Al+Alb before Mt complexes), large OH–Al–protein polymers formed, which were only partially intercalated into the interlamellar spaces of the clay. In all the complexes, the amounts of proteinic molecules sorbed usually increased by increasing the pH.     

Preparation and characterization of bio-nanocomposite films based on soy protein isolate and montmorillonite using melt extrusion

The non-biodegradable and non-renewable nature of plastic packaging has led to a renewed interest in packaging materials based on bio-nanocomposites (biopolymer matrix reinforced with nanoparticles such as layered silicates). Bio-nanocomposite films based on soy protein isolate (SPI) and montmorillonite (MMT) were prepared using melt extrusion. Effects of the pH of film forming solution, MMT content, and extrusion processing parameters (screw speed and barrel temperature distribution) on the structure and properties of SPI–MMT bio-nanocomposite films were investigated. X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used for structural characterization of the films. Properties of the films were determined by tensile testing, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and water vapor barrier measurement. The arrangement of MMT in the soy protein matrix ranged from exfoliated at lower MMT content (5%) to intercalated at higher MMT content (15%). There was a significant improvement in mechanical (tensile strength and percent elongation at break) and dynamic mechanical properties (glass transition temperature and storage modulus), thermal stability, and water vapor permeability of the films with the addition of MMT. The results presented in this study show the feasibility of using bio-nanocomposite technology to improve the properties of biopolymer films based on SPI.     

蒙脱石纳米复合材料基质制备研究

简要介绍了湖南某地钙基膨润土矿的矿石物质组成及性质 ,通过试验研究 ,提出了湿法分级提纯工艺流程 ,获得了蒙脱石含量 >90 %的膨润土精矿 ,为制备无机纳米复合材料提供了高性能的基质材料。     

对蒙脱石层电荷的测定

介绍了蒙脱石矿物晶格的层表面积、层电荷的概念；蒙脱石晶层中单价交换阳离子所占据的面积及层电荷的确定方法，并对不同种方法进行了比较。指出了在蒙脱石改性工艺中，研究蒙脱石层电荷的重要性。     

NE/OMMT纳米复合物与TPPi复配阻燃PP的制备与性能

采用酚醛环氧树脂／有机蒙脱土（NE／OMMT）纳米复合物与亚磷酸三苯酯（TPPi）复配作为阻燃剂,制备了阻燃聚丙烯（PP）;研究了各组分的质量比及用量等对PP的阻燃性能及力学性能的影响;并通过x射线衍射分析（XRD）对材料进行了表征。结果发现,NE／OMMT纳米复合物与TPPi对PP具有很好的协同阻燃作用,当NE、TPPi的质量分数分别为9％、6％,OMMT与NE的质量比为0.06时,PP的氧指数高达36．5％,且力学性能优良。XRD分析结果表明：OMMT经NE插层后,层间距扩大明显,与PP熔融共混后可产生部分剥离。