别嘌醇插层Zn/Al-NO3-LDH复合材料的组装及缓释性能

以共沉淀法和离子交换法制备别嘌醇插层Zn/Al-NO3-LDH复合材料,结合XRD、FT-IR、TG-DTA分析表明,别嘌醇进入LDH层间与层板相互作用形成超分子结构,提高了别嘌醇的耐酸性和热稳定性,且共沉淀法制备的别嘌醇插层LDH具有良好的缓释性能.提出了共沉淀法制备有机分子插层LDH过程中,存在易于客体进行离子交换和包埋的溶胶-凝胶中间形态的假设,可提高有机分子插层量.     

水滑石对IFR/HDPE复合材料的协效作用

利用熔融共混法制备了水滑石(LDH/)膨胀型阻燃剂(IFR/)高密度聚乙烯(HDPE)复合材料,并对复合材料的力学性能、阻燃性能、热稳定性能和燃烧炭层结构进行了研究。结果表明:LDH对复合材料具有明显的增强作用,在聚磷酸铵/丙三醇/三聚氰胺/HDPE体系中增强幅度最大;LDH能有效提高复合材料的氧指数,且在丙三醇和季戊四醇阻燃复合体系中能有效抑制熔滴和发烟量;LDH可以促进膨胀阻燃体系形成质密多孔炭层并,提高炭层的强度。     

Layered double hydroxide/NaSb(OH)6–poly(vinyl chloride) nanocomposites: Preparation,characterization, and thermal stability

A novel layered double hydroxide/NaSb(OH)₆‐based nanocomposite (Sb‐LDH) has been prepared via intercalation of thio‐antimonite (SbS₃^3?) and reconstruction of LDH using Mg‐Al LDH as precursors. It is composed of LDH nanolayers with thickness of 25 nm and NaSb(OH)₆ nanoparticles with diameter of 3–25 nm. The presence of NaSb(OH)₆ will decrease the decomposition intensity and hinder the decomposition of Mg‐Al LDH because of the potential synergetic effect. When applied to poly(vinyl chloride) (PVC) composites, both Mg‐Al LDH and Sb‐LDH can enhance the thermal stability and increase the decomposition temperature of PVC. Compared with Mg‐Al LDH, Sb‐LDH results in higher decomposition temperatures and whiteness and higher initial and long‐term stabilities due to the presence of NaSb(OH)₆, which can react with HCl and coordinate with Cl in the PVC chains. Because Mg‐Al LDH will accelerate the dehydrochlorination of PVC driving by the Lewis acid such as AlCl₃, the thermal stability of PVC decreases with increasing nanofiller loading. When 1 wt % Sb‐LDH was added, the color change time and Congo red time of PVC composites are 140 min and 154 min, respectively. With enhanced thermal stabilization, this novel LDH nanocomposite could gain promising application in thermal stabilizer for PVC resins. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

嗜热链球菌培养过程中的细胞凋亡研究

对直投型酸奶发酵剂中的嗜热链球菌进行了培养，测定了培养过程中菌体的细胞凋亡、菌体的生长曲线、LDH活力、LD含量。结果表明，嗜热链球菌培养过程中存在细胞凋亡现象，与菌体增殖和产酸规律有关。     

Exfoliated poly (styrene‐co‐methylstyrene) grafted‐polyaniline/layered double hydroxide nanocomposite synthesized by solvent blending method

Well defined poly (styrene‐co‐methylstyrene) grafted polyaniline/organo‐modified MgAl layered double hydroxide (LDH) was produced through solution intercalation method. After LDH nanoparticles were modified by the anion exchange reaction of MgAl (Cl) LDH with sodium dodecyl benzene sulfonate, Poly (styrene‐co‐methylstyrene) copolymers were synthesized by “living” free radical polymerization and then brominated with N‐bromosuccinimide. Afterwards, 1,4‐phenylenediamine was linked to brominated copolymers and prepared functionalized copolymer with amine. Poly (St‐co‐MSt)‐g‐PANI, has been synthesized by adding solution of ammonium persulfate and p‐toluenesufonic acid in DMSO solvent. Finally, Poly (styrene‐co‐methylstyrene) grafted‐Polyaniline/LDH nanocomposites were prepared by solution intercalation method. Characterization of these well‐defined nanocomposites included FT‐IR, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimeter, transmission electron microscopy, and X‐ray diffraction. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

牛磺酸复合饮料抗疲劳的实验研究

通过动物试验研究牛磺酸复合饮料的抗疲劳作用。将雄性SD大鼠按体重随机分为4组,即空白对照组、阳性对照组、低剂量和高剂量牛磺酸复合饮料组。在给予受试物30d后测定各组大鼠爬杆时间和负重游泳的持续时间。试验前及试验第35天,大鼠在水温25℃±1℃的水中游泳90min,测定乳酸脱氢酶（LDH）、血乳酸（LAC）、血尿素氮（BUN）和肝糖原等生化指标。结果显示牛磺酸复合饮料组大鼠爬杆、游泳时间明显长于对照组（P〈0．01）;服用牛磺酸复合饮料的大鼠LDH活力、肝糖原均比对照组显著增加（P〈0．01）,运动后血乳酸水平及BUN明显降低（P〈0．01）。由此可得出牛磺酸复合饮料具有抗疲劳作用。     

Layer-by-layer self-assembly of polyimide precursor/layered double hydroxide ultrathin films

The layer-by-layer (LBL) self-assembly has been extensively used as a simple and effective method for the preparation of polyelectrolyte multilayer films. In this work, we utilized this unique method to prepare polyimide precursor/layered double hydroxide (LDH) ultrathin films. Well-crystallized Co-Al-CO₃ LDH and subsequent anion exchanged Co-Al-NO₃ LDH were prepared and characterized by scanning electron microscopy and X-ray diffraction (XRD). By vigorous shaking of the as-prepared Co-Al-NO₃ LDH, positively charged and exfoliated LDH nanosheets were obtained. Atomic force microscopy and XRD investigations indicated the delamination of LDH nanosheets. The precursor of polyimide, poly(amic acid) tertiary amine salt (PAS) was prepared by the polycondensation of dianhydride and diamine, and subsequent amine salt formation. By using the LBL method, heterogeneous ultrathin films of PAS and LDH were prepared. The formation of the ordered nanostructured assemblies was confirmed by the progressive enhancement of UV absorbance and the XRD results.