【作者】 贾猛猛；

【导师】 李丽芳；

【作者基本信息】 山东农业大学 ， 农药学， 2011， 硕士

【摘要】 我国是世界上第二大农药生产国,但与发达国家相比,长期存在剂型结构不合理,制剂质量差等问题。目前我国的农药制剂仍以传统的粉剂、乳油和悬浮剂为主,技术落后,药效差,且对环境污染严重。近年来,以安全、经济、环保为目标的农药新剂型研制日益受到重视,其中农药控释剂型已成农药剂型领域的研究热点。类水滑石(Hydrotalcite-like compounds,HTlc)是由两种或两种以上金属元素组成的具有水滑石层状晶体结构的氢氧化物,层片带结构正电荷,层间存在可交换的阴离子。HTlc层间可作为微型储存器,将农药分子插入其中制成农药-HTlc纳米杂化物,因空间位阻效应和农药分子与层板间的相互作用可实现对农药分子的控释。近期,农药-HTlc纳米杂化物的制备及在农药控释剂型中的应用备受关注。本文选取甲氨基阿维菌素苯甲酸盐(MAAV)为客体分子,以HTlc为主体,采用二次组装法制备了农药-HTlc纳米杂化物,考察了其释放行为,探讨了释放机理。以期掌握农药-HTlc纳米杂化物的关键制备技术,了解其农药控释规律,为进一步的实际应用奠定基础。所得主要结论归纳如下:通过“二次组装法”把水难溶电中性农药甲氨基阿维菌素苯甲酸盐成功插入到HTlc层间,制备合成MAAV-SDS-HTlc杂化物。由X射线衍射(XRD)和傅里叶红外变换光谱(FT-IR)图谱证明了MAAV成功的插入到了SDS-HTlc疏水层间,导致了层间距进一步的增大。TG-DTA分析结果表明,将MAAV插入到HTlc层间,提高了MAAV的热稳定性。不同pH环境下MAAV从MAAV-SDS-HTlc杂化物中的释放行为表明MAAV-SDS-HTlc杂化物是一个可以控制释放的载药系统,MAAV-SDS-HTlc在pH5.8和pH8.0中的释放速率较快,当在pH7.0的环境中,释放速率相对缓慢。释放动力学研究表明其释放行为符合二级动力学模型。采用粒径分布以及Zeta电位法分析了不同润湿分散剂对MAAV-SDS-HTlc杂化物在水中悬浮性能,结果表明:烷基萘磺酸缩聚物钠盐Morwet D-425与MAAV-SDS-HTlc结合修饰后可以使杂化物在水中稳定悬浮。通过对润湿剂、分散剂、崩解剂、粘结剂等助剂的筛选,采用正交试验设计的方法确定了26%MAAV-SDS-HTlc杂化物水分散粒剂的最佳配方(以质量分数计):MAAV-SDS-HTlc杂化物78%,润湿剂SDS+RS为6%,分散剂Morwet D425为5%,崩解剂尿素为10%,粘结剂蔗糖为1%。该产品悬浮率90%以上,崩解时间小于180s,热贮[(54±2)℃,14d]分解率小于5%,且产品各项指标符合水分散粒剂的要求。更多还原

【Abstract】 Nowadays in China, the second biggest country of pesticide producing, preparations forms are mainly powder, oil concentrate and suspension concentrate, which are irrational and large application. Pesticide has brought many ignorant effects such as air pollutions, environmental destroy, food safety and so on, which has baffled agricultural sustainable development. Now the hit research trends of pesticide forms in the world are focused on controlled-release formulations.Hydrotalcite-like compounds (HTIc), also called Layered double hydroxides (LDHs), consisting of divalent and trivalent metal ions and with the same layered crystal structure as hydrotalcite, are a class of layered materials which has been paid a great of attention in recent years. The interlayer region of HTIc may be considered as a microvessle, some pesticide and drug molecules may be intercalated into the gallery of HTIc to form pesticide/drug-HTIc nanohybrids. The nanohybrids may evidently inhibit the release of moleculars in the interlayer. So pesticide/drug-HTIc nanohybrids are greatly potencial controlled-release formulations.HTIc was chosen as host material and emamectin benzoate (MAAV) as guest species, have been successfully intercalated into HTIc using re-assemble method.The synthesis strategy and the properties of nanohybrids, released behavior, released mechanism and the relationship between structures and released behavior of nanohybrids were systematically studied. The main contents of this paper are as follows.One charge-neutral and poorly water-soluble pesticide, emamectin benzoate (MAAV), was first successfully intercalated into the gallery of Mg-Al hydrotalcite-like compounds (HTlc) by re-assemble method, to obtain MAAV-HTlc nanohybrids.The prepared samples were characterized by X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). Results showed that MAAV was successfully retained in the hydrophobic region of SDS-HTlc, corresponding to a distinct interlayer gallery increase. The thermal stability of MAAV-SDS-HTlc were investigated by thermogravimetry and differential thermal analysis (TG-DTA) showed that the modified HTlc increase the thermal stability of MAAV.The release kinetics of MAAV from the nanohybrids was investigated at different pH buffer solution. The nanohybrids can well control the release of MAAV, showing they are a potential pesticide controlled-release formulation. MAAV-SDS-HTlc nanohybrids exposed to pH 5.8 and 8.0 released MAAV more quickly. When the pH changed to 7.0, the rate of release decreased. It was found that the MAAV release kinetic processes of the nanohybrids can be described with pseudo-second-order model.Using particle size distribution and Zeta potential analysis of the different wetting and dispersing agents on the MAAV-SDS-HTlc hybrid materials suspended in the water performance. The results show that sodium alkyl naphthalene sulfonate condensation Morwet D-425 and MAAV-SDS-HTlc with modified can make hybrid materials stable suspension in water.The preparation method of the water dispersible granules of 26% emamectin benzoate-HTlc was studied. Through the test, we selected the suitable wetting agent, dispersant, disintegrant and binder and determined the optimum formula using the orthogonal test design. The new formulation included Emamectin benzoate-HTlc, wetting agent SDS+RS, dispersant MorwetD425, disintegrant urea, binder saccharose in mixture with mass fractions were 78%, 6%, 5%, 10% and 1%.The experimental results showed that the suspension rate of products was over 90%, the dispersion time was less than180 seconds and the decomposition rate of its active ingredient was less than 5% at (54±2)°C with 14 days, which conformed to the requirements of the formulation.更多还原