Al掺杂ZnO超细粉体的制备及表征

利用溶胶-凝胶法在一系列不同实验条件下制备出了ZAO超细粉体,用正交试验法对实验条件进行设计,确定了最佳实验条件,并利用差热-热重分析仪、X-射线衍射仪、扫描电镜等对得到的ZAO超细粉体进行了分析和表征。结果表明,在煅烧温度1 150℃,乙醇与水的比例为2.5,醋酸锌浓度为2.5 mol/L,柠檬酸三胺浓度为0.5 mol/L,氧化铝与氧化锌的质量比为3%的实验条件下,能够得到具有交错柱状晶体的ZAO超细粉体。同时,在850℃处成功对ZnO进行了铝的掺杂。     

紫杉醇硅胶表面分子印迹纳米颗粒的制备

以紫杉醇为模板分子,紫杉醇上的羟基与异氰酸酯丙基三乙氧基硅烷(IPTS)反应形成共价复合物,然后和交联剂正硅酸乙酯(TEOS)通过溶胶-凝胶的方法涂覆在纳米硅胶表面上,以热裂解的方式去除模板分子后形成紫杉醇硅胶表面分子印迹纳米颗粒。通过吸附实验分析研究了紫杉醇硅胶表面分子印迹纳米颗粒的亲和性能,结果表明印迹纳米颗粒对紫杉醇有良好的亲和性。     

Formation of macroporous gel morphology by phase separation in the silica sol-gel system containing nonionic surfactant

The phase separation and gel formation behavior in an alkoxy-derived silica sol-gel system containing Ci6EOi5 has been investigated. Various gel morphologies similar to other sol-gel systems containing organic additives were obtained by changing the preparation conditions. Micrometer-range interconnected porous gels were obtained by freezing transitional structures of phase separation in the sol-gel process. The dependence of the resulting gel morphology on several important reaction parameters such as the starting composition, reaction temperature and acid catalyst concentration was studied in detail. The experimental results indicate that the gel morphology is mainly determined by the time relation between the onset of phase separation and gel formation.     

有机染料在SiO_2凝胶玻璃基质中的荧光谱线位移机制

研究探明了有机染料的荧光发射波长的位移机制 .R6G和 RB染料随掺杂浓度的提高而出现的谱线红移是由于二聚物的形成导致的 ,而凝胶玻璃中 C12 0染料的红移是由溶剂效应引起的 .同时 ,Si O2凝胶玻璃中 RB的谱线红移也可能由酯化反应所导致 ,这种红移在热处理至 3 0 0℃时可由 RB的内酯化产物形成而降低     

Structure characterization of F-doped silica glass

Pure and fluorine-doped silica glass were fabricated by plasma chemical vapour deposition (PCVD) and characterized using Raman and infrared spectrum. The change in Raman intensity of 945 cm⁻¹ peak, relating to ≡Si—F stretching vibration, agrees with the change of F content. Compared with measured wavenumber in IR spectrum, the calculated absorption wavelength confirms the incorporation form of F into the glass, the detail of which is a tetrahedron with a Si atom in the center coupled with one F atom and three network O atoms. Such structure identification may be useful for explaining some properties of F-doping silica glass.     

改善非极性聚合物表面润湿性能的研究

研究了用硅胶沉积於聚丙烯固体表面来改善其润湿性能的方法．着重讨论表面活性剂种类及溶液酸度对硅胶附着牢度的影响．通过系列实验获得了较满意的硅胶附着牢度，并分析了获得该附着牢度的原因．     

溶胶凝胶法制备锆钛酸钡超细粉体

为研究用于合成纳米级高纯锆钛酸钡陶瓷粉的溶胶凝胶制备工艺.工艺采用柠檬酸锆为锆源,低价的乙酸与己二醇为溶剂,不采用己二醇独甲醚等有毒溶剂,不仅生产成本显著降低,且为环境友好材料,易于实现产业化.对采用乙酸钡-柠檬酸锆-钛酸四丁酯-己二醇体系制备的锆钛酸钡纳米粉体,通过XRD、TEM、TG-DTA分析,研究确定了溶胶、凝胶及烧结工艺.确定的最佳溶胶工艺条件为:温度40℃,pH 3.5,浓度0.05~0.1mol/L.凝胶经800℃烧结,可获得粒度为40 nm,近球形的单一钙钛矿相锆钛酸钡粉体.     

Preparation and characterization of ferromagnetic calcium alginate complex gel

Fe₃O₄ suspension, derived from chemical co-precipitation and subsequent ultrasonic treatment, was embedded into calcium alginate to form complex gel. Both gel beads and injectable gel floc were obtained by slightly tailoring the preparation condition. SEM analysis showed that the iron oxide was dispersed homogenously in nanometer. TGA profiles revealed that the content of Fe₃O₄ in beads was about 7.2%. Funded by the University Special Item of Natural Science Foundation of Fujian Province (No. 2006J0441)     

酶解产物人参皂苷Rh_2、Rh_3的二氯甲烷层析分离

人参皂苷Rh2、Rh3具有一定的抗癌作用,而这些稀有皂苷在传统红参中的含量甚微。为了获得纯度较高的人参皂苷单体,将人参二醇类皂苷经酶转化等方法处理,得到以人参皂苷Rh2和Rh3为主的混合物。常压下,用二氯甲烷-甲醇作为洗脱液变换梯度进行硅胶柱分离,分别采用流动相V(二氯甲烷)∶V(甲醇)=7∶0.10、7∶0.13、7∶0.15、7∶0.18、7∶0.2、7∶0.3渐变梯度进行洗脱,当流动相V(二氯甲烷)∶V(甲醇)=7∶0.3时,成功分离出人参皂苷Rh2和Rh3。经高效液相色谱检测,为反式的二十、二十二碳烯Rh3和顺式的二十、二十二碳烯Rh3(即Rk2)混合物,纯度达到95%以上;也得到较纯的Rh2,经高效液相色谱检测为20(S)-Rh2和20(R)-Rh2异构体的混合物,纯度达到85%以上。     

Facile and controlled synthesis of silica sol nanospheres through a modified sol-gel process

An effective and reproducible preparation of silica sol nanospheres via a modified sol-gel process has been described. Monodisperse and stable silica sol nanospheres with uniformsize were successfully obtained through the optimized synthesis in which the mixture of tetraethyl orthosilicate （TEOS） and ethanol was followed by the addition of water and ammonium hydroxide （NH3） separately, and the size of silica sol spheres was strictly controlled in the range of 25-119 nm with a narrow size distribution by fine adjustment of several reaction parameters. Results showed that in the presence of low concentration of TEOS, spheres size rose first and reached maximum when H2O concentration was up to 66 g/L. However, the diameter of silica sol spheres decreased above 66 g/L of H2O concentration. Furthermore, it was also found that the size and size distribution of silica sol nanospheres were affected by NH3 concentration. As NH3 concentration increased from 15 to 35 g/L, the diameter declined from 83 to 64 nm. Nevertheless, higher NH3 concentration would result in relatively broad size distribution, and gelation occurred when NH3 concentration reached 44 g/L. In addition, the effect of the different feed rates ofNH3 on the size growth of silica sol nanospheres was also discussed.     

硅胶相反射散射分光光度法测定矿样中痕量锆

测定了硅胶吸附锆－BPR配合物的条件及硅胶相中配合物的组成，并采用固相反射散射分光光度法直接测定硅胶相中锆的含量。方法的检出限为0.13mg/L，相对标准偏差为4.3%，用于矿样中锆的测定，回收率为93％。     

硅胶吸附甘油在酶法催化大豆油转酯化反应中的作用

对硅胶吸附甘油在固定化脂肪酶催化大豆油转酯化反应中的作用进行了研究,考察了反应条件如硅胶种类,加入时间,脂肪酶加入量,体系水含量,反应温度等对转化率的影响以及固定化酶的稳定性。结果表明,反应开始时加入与大豆油质量比为1∶13.3的硅胶,加入油重1%的水,在40℃反应4批次96 h,转化率平均提高9%,使用硅胶吸附甘油能提高酶法转酯化率和延长固定化酶的使用寿命。     

硅胶吸附甘油在酶法催化大豆油转酯化反应中的作用

对硅胶吸附甘油在固定化脂肪酶催化大豆油转酯化反应中的作用进行了研究,考察了反应条件如硅胶种类,加入时间,脂肪酶加入量,体系水含量,反应温度等对转化率的影响以及固定化酶的稳定性。结果表明,反应开始时加入与大豆油质量比为1∶13.3的硅胶,加入油重1%的水,在40℃反应4批次96 h,转化率平均提高9%,使用硅胶吸附甘油能提高酶法转酯化率和延长固定化酶的使用寿命。     

纤维素-二氧化硅复合颗粒的制备与表征

探索了可用作色谱填料的纤维素-SiO2复合颗粒的制备方法,将纤维素和硅胶溶于NaOH／尿素体系中,得到纤维素-SiO2溶液,用溶胶一凝胶转相法制得复合颗粒．研究了乳化剂用量、搅拌转速、纤维素分子量以及纤维素和SiO2的投料比对所制备的复合颗粒粒径和形貌的影响,以扫描电镜、粒径分析等对复合颗粒进行了表征．发现粘度小的分散相和分子量小的纤维素适合制备粒径大的复合颗粒,反之亦然．当纤维素与SiOz的投料比大于3：1时,复合颗粒呈球形,小于3：1时,多数颗粒的形状为无定形;当乳化剂Span80的用量为10％,搅拌转速为600r／min时,复合颗粒的形状较规则．在不同的条件下,所制备颗粒的体积平均粒径为9～45μm,比表面积在110～4802／g之间．调节乳化剂用量、搅拌转速、纤维素分子量以及纤维素与SiO2的投料比,能制备出粒径适当、比表面积大的复合颗粒,这些颗粒具有介孔结构,且孔径分布较均匀,机械强度高,适合用作色谱分离填料．     

微硅粉/聚丙烯复合材料制备与表征

低温煅烧微硅粉并用硅烷偶联剂Si69对其进行改性,再分别将未改性和改性微硅粉作为无机填料与聚丙烯混合后制备复合材料。未改性微硅粉掺入量为复合材料总质量的2%,改性微硅粉掺入量分别为总质量的1%、2%、3%、4%及5%,并分别在155℃、168℃、175℃温度下制备试样。测试各试样的拉伸强度、断裂伸长率、弯曲强度、冲击强度,观察其断裂面的形貌,并进行红外检测,研究改性微硅粉在不同掺量下对聚丙烯性能的影响。结果表明:改性微硅粉占复合材料质量分数的2%时复合材料的拉伸强度、弯曲强度及冲击强度得到改善;未改性或改性微硅粉加入量大于4%时会降低以上强度;用热压成型制备试样时,温度高于168℃即可成型良好。     

硅胶结合剂、硅铝胶结合剂对耐火浇注料性能的影响

以溶胶—凝胶结合浇注料为对象,研究硅胶含量、硅铝胶含量（不同莫来石胶）对浇注料试样的体积密度、显气孔率、吸水率、烧后线变化率、抗渣性能的影响。结果表明：当硅胶作结合剂,质量分数在8％左右时,试样性能较理想;当硅铝胶作结合剂,质量分数为6％时,试样性能也较理想。硅铝胶质量分数为6％试样的体积密度、显气孔率、吸水率、烧后线变化率优于硅胶质量分数为8％的试样,但侵蚀系数和渗透系数劣于硅胶质量分数为8％的试样。     

Synthesis and characterization of Nd doped M-type hexagonal barium ferrite ultrafine powders

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溶胶-凝胶技术研究及其应用

阐述溶胶-凝胶技术的研究发展现状,以及该技术的基本原理、工艺过程及应用.     

铝-硅胶粉末复合材料快速成形试验初探

简述以快速制造技术制造铝－硅胶粉末复合材料方法的初步试验和研究，对快速制造的方法、铝粉与硅胶粉的混合比例、压坯性能的初步分析，以探讨快速制造铝－硅胶复合材料的可行性。