3,3,3-三氟丙基甲基二甲氧基硅烷合成研究

通过滴加3,3,3-三氟丙基甲基二氯硅烷与甲醇进行醇解反应,合成了3,3,3-三氟丙基甲基二甲氧基硅烷,考察了不同的溶剂、温度、加料速度等对产物的影响,确立了最佳的反应条件。并用GC-MS对产物进行定量和定性分析。     

3,3,3-三氟丙基三甲氧基硅烷的合成研究

以3,3,3-三氟丙基三氯硅烷和甲醇为原料,采用溶剂法合成3,3,3-三氟丙基三甲氧基硅烷,讨论了氮气流速、反应温度、原料配比、溶剂种类、滴加方式等因素对产物收率的影响.并用GC-MS对产物进行了分析.通过实验得出该反应较优的反应条件为:用正己烷作溶剂,N2流速为100mL/min,3,3,3-三氟丙基三氯硅烷和甲醇的摩尔比为1∶3.1,反应温度在70℃左右,3,3,3-三氟丙基三甲氧基硅的产率可达89.4%.     

3-氯丙基三甲氧基硅烷合成新方法的研究

为提高产率、降低成本,以3-氯丙烯和三甲氧基硅烷为原料、水合三氯化钌为催化剂进行3-氯丙基三甲氧基硅烷的一步合成反应,研究了反应温度、催化剂浓度、原料的加料方式、反应时间、原料的配比对产物收率的影响.结果表明,最佳的反应条件为反应温度80℃、钌催化剂质量分数63 μg/g、3-氯丙烯向三甲氧基硅烷中滴加方式、三甲氧基硅...     

乙烯基三(2,2,2-三氟)乙氧基硅烷的合成研究

以乙烯基三氯硅烷和三氟乙醇为原料,二氯甲烷为溶剂合成了乙烯基三(2,2,2-三氟)乙氧基硅烷。考察了原料配比、溶剂用量、Ar2流量、三氟乙醇滴加速度、温度、反应时间等因素对产物收率的影响,确定了最佳合成条件。并运用FT-IR、1 H-NMR、13 CNMR对产物结构进行了表征。     

γ-缩水甘油醚氧丙基三甲氧基硅烷合成工艺研究

评价了氯铂酸-异丙醇、氯铂酸-四氢呋喃体系在烯丙基缩水甘油醚和三甲氧基硅烷硅氢加成反应中的催化性能;重点进行了氯铂酸-异丙醇体系催化合成γ-缩水甘油醚氧丙基三甲氧基硅烷的工艺研究.其最佳工艺条件是催化剂:三甲氧基硅烷:烯丙基缩水甘油醚为1.42×10-5:1:1(物质的量),反应温度约85℃,反应时间60min,产物收率约72.58%.用傅立叶红外光谱对化合物进行了表征.     

催化合成三氟丙基三氯硅烷的研究

以3,3,3-三氟丙烯与三氯硅烷为原料在铂催化剂作用下合成3,3,3-三氟丙基三氯硅烷,考察了催化剂活化温度、反应温度、催化剂用量等对反应的影响.确立了最佳的反应条件.     

3-氯丙基甲基正丁基甲氧基硅烷的合成与表征

利用3-氯丙基甲基二甲氧基硅烷、金属镁、正溴丁烷合成了3-氯丙基甲基正丁基甲氧基硅烷,通过FT-IR、1 H-NMR、13 CNMR、DEPT135对产物进行结构表征,并讨论了影响产物收率的因素,确定了最佳反应条件。     

甲基丙烯酸甲酯-γ-甲基丙烯酰氧基丙基三甲氧基硅烷细乳液共聚合研究

将甲基丙烯酸甲酯(MMA)单体与反应性单体γ-甲基丙烯酰氧基丙基三甲氧基硅烷(A-174)进行细乳液共聚合,获得了MMA-CO-(A-174)共聚物乳液。研究了聚合温度、助稳定剂用量、A-174用量及水相中pH调节剂用量对聚合过程动力学的影响。利用红外光谱和透射电镜对共聚产物组成和乳胶粒子形态进行了表征。用气相色谱法(GC)测定了共聚物乳液中微量甲醇含量．结果表明,细乳液聚合工艺可以避免活性硅烷A-174的反应性官能团在聚合过程中被水解损耗。     

3-氨丙基三甲氧基硅烷为涂层的反向毛细管电泳柱的制备及性能讨论

涂层柱的制备技术一直是毛细管电泳技术中的一个重要部分,合成活性三甲氧基硅烷修饰的三亚甲基亚胺衍生物,并用简单的方法把此高分子聚合物键合于石英毛细管内壁上,并利用不同pH值缓冲溶液在测定该毛细管中的电渗速度和电渗淌度,可在低电渗流的条件下可实现无机离子的分析。     

γ-（甲基丙烯酰氧基）丙基三甲氧基硅烷改性聚氨酯的研究

以异佛尔酮二异氰酸酯（IPDI）、聚四氢呋喃二醇（PTMG）、γ-（甲基丙烯酰氧基）丙基三甲氧基硅烷（MEMO）为基本原料,制备了硅烷改性聚氨酯乳液,并外加氮丙啶进一步提高了胶膜的性能。衰减全反射傅里叶变换红外光谱（ATR-FT-IR）对产物的结构进行了表征,考察了MEMO含量对乳液粒径、胶膜耐水性、力学性能及热性能的影响,同时对胶膜的结晶性及接触角进行了测试。结果表明ATR-FT-IR证实了MEMO成功地反应到了聚氨酯分子链上;在m（MEMO）=5.67%,m（AZ）=2%时,胶膜的耐水性最低为14.84%,胶膜的最大拉伸强度为17.334MPa,断裂伸长率为232.56%,改性后聚氨酯的热稳定性提高,结晶性及表面能均降低。     

溶剂挥发法制备苯乙烯微胶囊

采用简单易控制的溶剂挥发法成功制备了聚砜材料包覆苯乙烯的自修复微胶囊,通过核磁共振氢谱(1H-NMR)、扫描电子显微镜(SEM)、元素分析仪和热重分析仪(TGA)对微胶囊的化学结构、表面形貌及其热性能进行了研究.结果表明,选择0.5％的聚乙烯醇表面活性剂,700 r/min乳化转速、芯壁比2∶1时制得的微胶囊表面光滑,体积平均粒径为120μm,并且分布比较窄,微胶囊在室温下具有一定缓释性.     

2-溴-3,3,3-三氟丙烯的合成与应用

介绍了2溴3,3,3三氟丙烯的用途及合成方法。     

Optimization of the emulsification and solvent displacement method for the preparation of solid lipid nanoparticles

Objective: The essential aim of this article is to prepare solid lipid nanoparticles (SLNs) by emulsification and solvent displacement method and to determine the best process conditions to obtain submicron particles. Methods: The emulsification and solvent displacement method is a modification of the well-known emulsification–diffusion method, but without dilution of the system. The extraction of the partially water-miscible solvent from the emulsion globules is carried out under reduced pressure, which causes the diffusion of the solvent toward the external phase, with subsequent lipid aggregation in particles whose size will depend on the process conditions. The critical variables affecting the process, such as stirring rate, the proportion of phases in the emulsion, and the amount of stabilizer and lipid, were evaluated and optimized. Results: By this method, it was possible to obtain a high yield of solids in the dispersion for the lipids evaluated (Compritol^® ATO 888, Geleol^®, Gelucire^® 44/14, and stearic acid). SLNs of up to ～20 mg/mL were obtained for all lipids evaluated. A marked reduction in size, between 500 and 2500 rpm, was seen, and a transition from micro- to nanometric size was observed. The smaller particle sizes obtained were 113 nm for Compritol^® ATO 888, 70 nm for Gelucire^® 44/14, 210 nm for Geleol^®, and 527 nm for stearic acid, using a rotor–stator homogenizer (Ultra-Turrax^®) at 16,000 rpm. The best phase ratio (organic/aqueous) was 1 : 2. Conclusions: The process proposed in this study is a new alternative to prepare SLNs with technological potential.     

Controlled synthesis of dense MgFe2O4 nanospheres by ultrasonic spray pyrolysis technique: Effect of ethanol addition to precursor solvent

We present the results of controlled synthesis of spherical shape magnesium ferrite (MgFe₂O₄) dense nanoparticles by using ultrasonic spray pyrolysis (USP) method without any post-annealing processes. A new strategy was proposed to improve nano-crystallinity and observed morphology by ethanol (EtOH) addition in the initial precursor solution of MgFe₂O₄. Influence of EtOH, not only decrease the synthesized secondary particle size but also enhancing crystallization into MgFe₂O₄ single phase cubic structure. We observe that average nanosphere size decrease from 220 to 189?nm but increases of crystallite size from 9.6 to 19.2?nm with increasing the amount of EtOH from 0 to 20?vol%. Also, surface morphology revealed that nanospheres with some irregular shape and rough surface appear in case of EtOH additives. The magnetic properties are studied and different parameters viz. saturation magnetization, remanence, and coercivity have been correlated with crystallite size.     

长链烷基硅烷偶联剂的合成研究

以甲基二氯硅烷与1-十二碳烯在铂催化剂作用下合成了甲基十二烷基二氯硅烷,并以无溶剂气-液相反应法醇解得到了甲基十二烷基二甲氧基硅烷。考察了催化剂对加成反应及原料配比、温度、填料大小等因素对醇解反应的各种影响。确立了最佳的反应条件。     

Synthesis and luminescence properties of YVO4:Eu cobblestone - like microcrystalline phosphors obtained from the mixed solvent - thermal method

The mixed solvent-thermal method has been developed for the synthesis of YVO₄:Eu³⁺ luminescent materials in the N, N-dimethylformamide (DMF)/ de-ionized water (DIW) solution. The samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electronic microscope (TEM), UV/vis absorption and photoluminescence spectroscopies. The results demonstrate that we have obtained the uniform YVO₄:Eu³⁺ cobblestone - like microcrystalline phosphors in the mixed solution of DMF and DIW, which are different to the as-obtained YVO₄:Eu³⁺ nanoparticles in pure DIW. And the as - prepared YVO₄:Eu³⁺ microcrystalline particles are composed of numerous nanoparticles. The assembling phenomenon of the nanoparticles is strongly affected by the pH value of the solution and the volume ratio of DMF/DIW. Under UV excitation, the samples can emit the bright red light. While, the photoluminescence (PL) intensities of YVO₄:Eu³⁺ show some difference for samples obtained under the different reaction conditions. This is because that different microstructures of samples result in different combinative abilities between the surface and the adsorbed species so as to produce the different quenching abilities to the emission from Eu³⁺ ions.     

溶剂蒸发法制备氯离子触发型微胶囊

通过溶剂蒸发法制备囊壁嵌入硫酸铅(PbSO4)的十六烷/聚甲基丙烯酸甲酯(PMMA)有机-无机复合微胶囊,利用络合原理在囊壁中嵌入与氯离子发生络合反应的硫酸铅,从而达到对氯离子触发。通过激光粒径分析、十六烷检测仪和扫描电子显微镜(SEM)来确定微胶囊的制备工艺参数和触发效果。结果表明,5%的聚乙烯醇(PVA)做乳化剂,400r/min乳化搅拌转速制备出的微胶囊粒径在100μm左右,粒径分布范围比较窄,且PbSO4在壁材上分布很均匀。此外,微胶囊在不同浓度的盐水中和不同的时间内触发的效果不同。     

Preparation of PLGA nanoparticles using TPGS in the spontaneous emulsification solvent diffusion method

D-alpha-tocopheryl poly (ethylene glycol) 1000 succinate (TPGS) is a widely used form of vitamin E that has been used as a solubilizer, an emulsifier and as a vehicle for drug delivery formulations. In this study, poly lactide-co-glycolide (PLGA) nanoparticles were prepared by spontaneous emulsification solvent diffusion (SESD) method. TPGS as an emulsifier and further as a matrix material blended with PLGA was used to enhance the encapsulation efficiency and improve the drug release profile of nanoparticles. Rifampicin and estradiol valerate were used as model drugs with different water solubility. The effect of formulation parameters such as drug/polymer ratio, oil phase combination, volume and surfactant content was evaluated. The surface morphology and size of the nanoparticles were studied by scanning electron microscopy (SEM) and laser light scattering. Drug encapsulation efficiency and in vitro drug release profiles of nanoparticles were determined using high performance liquid chromatography (HPLC). The nanoparticles prepared in this study were spherical with size range of 150–250?nm. It was shown that TPGS was a good emulsifier for producing nanoparticles of hydrophobic drugs and improving the encapsulation efficiency and drug loading and drug release profile of nanoparticles. However, the drug loading efficiency of rifampicin, a slightly water-soluble molecule, was significantly lower than that of estradiol valerate, a water insoluble molecule.