微囊藻载戊唑醇制备缓释剂及其释放行为

以微囊藻为吸附载体、卡波树脂为包衣剂制备戊唑醇农药缓释剂,对微囊藻和缓释剂进行了表征,研究了微囊藻的吸附和释放行为. 结果表明,30℃下戊唑醇在乙醇和异丙醇中的饱和吸附量分别为18.68和20.1 mg/g,平均每个微囊藻吸附1.04×109个戊唑醇分子. 包裹10%卡波树脂的缓释剂具有很好的缓释功能,在乙醇/水(1:1, j)介质中累计释放时间长达204 h,累积释放率为74.5%.     

甲维盐聚乳酸微球缓释性能及室内毒力的初步测定

[目的]对甲维盐聚乳酸微球的缓释性能进行初步评价。[方法]采用高效液相色谱法比较甲维盐微球与微乳剂、原药光解的差异以及测定甲维盐聚乳酸微球中甲维盐在水中的释放速率,并进行室内毒力测定,将甲维盐微球制剂与常规剂型微乳剂的毒力进行对比。[结果]甲维盐微球自然光照10 h后光解率为31.74%,明显低于甲维盐在原药中的光解率82.22%和在微乳剂中的光解率80.04%;甲维盐微球在水中的缓释效果较为明显,60 d释放70%左右,并且甲维盐微球制剂在施药60 d后对小菜蛾2龄幼虫的死亡率仍达到63.33%,比微乳剂的药效更为持久。[结论]甲维盐微球制剂具有明显的缓释性能,并且持效期可达60 d以上。     

蓝藻为载体的阿维菌素抗紫外缓释剂的制备及其性能

以滇池蓝藻为载体,利用其抗紫外特性,用卡波姆树脂包裹蓝藻-阿维菌素(Avermectin, Av)粉,制成阿维菌素抗紫外缓释剂,利用FT-IR, SEM和HPLC等对蓝藻和缓释剂进行表征,研究其吸附与释放行为. 结果表明,Av在异丙醇中的饱和吸附量为160.81 mg/g,包裹10%卡波姆树脂的抗紫外缓释剂具有很好的缓释功能,在乙醇/水(4:1, j)中释放20 d,累计释放率为51.8%,释放机制是Fick扩散和骨架溶蚀的双重机制. 经4 h紫外光照射,含蓝藻的制剂中Av残留量为61%,不含蓝藻的制剂中Av残留量为39%.     

溶剂蒸发法制备甲维盐微胶囊及其性能表征

[目的]针对甲维盐传统加工剂型在实际应用过程中易光解、持效期短等缺点,采用溶剂蒸发法制备了甲维盐微胶囊。[方法]通过单因素和正交试验L9(34)优选了工艺参数,并对微胶囊理化特性及释放性能进行表征。[结果]溶剂用量、壁材用量和剪切速率显著影响微胶囊的平均粒径;壁材用量和乳化剂用量显著影响微胶囊的包封率。正交试验获得的优化配方为1%甲维盐,30%二氯甲烷,0.8%乙基纤维素,4%吐温-20,剪切速率22 000 r/min。所获得的甲维盐微胶囊粒径适中(16.83μm),包封率为47.69%,具有良好的缓释性能。[结论]该研究获得了性能较好的甲维盐微胶囊产品,对使用溶剂蒸发法制备其他农药微胶囊也有一定的借鉴作用。     

以微囊藻为载体制备戊唑醇缓释剂

利用天然藻为载体,采用喷雾干燥的方法得到了微囊藻的微球,在其表面吸附杀菌剂戊唑醇,加入适量成膜剂制备新型环保的农药缓释剂型。对藻的吸附能力及其在特定溶剂的释放行为进行分析表明：该载体藻类具有较高的吸附能力,吸附量最大可达到18000mg/kg;缓释剂型有较好的缓释效果,最长可达200h,最终释放量为80%。该方法既经济又环保,具有较好的应用前景。     

蓝藻生物资源的开发与应用

利用环境废弃物蓝藻,开发SiO2新材料和抗紫外农药缓释剂型。合成了形貌规整、平均粒径为1.5μm、粒径分布较窄的SiO2实心与空心微球,采用TG、SEM、FE-SEM对其进行了表征,研究了其制备液相色谱固定相的方法和分离纯化蛋白质的条件。以蓝藻为载体,制备了农药(戊唑醇、阿维菌素、甲维盐)抗紫外缓释剂,研究了蓝藻对上述农药的吸附、缓释行为和抗紫外性能,吸附量达到160.81 mg/g,半量释放时间在40 d左右,蓝藻吸附农药样品与商品化制剂相比,抗紫外能力相对提高了56.4%,相对降低了农药的大田使用量,探索了蓝藻作为农药制剂载体的可行性。     

木质素季铵盐-海藻酸钠聚合物负载阿维菌素粉体的制备及抗紫外光性能分析

以三甲基木质素季铵盐-海藻酸钠(QL-SA)为载体,用物理混合法制备了阿维菌素缓释聚合物(AVM-QL-SA),利用FT-IR对其结构进行了表征,探讨了交联剂用量、药物加入量、体系pH值等因素对载药量和包封率的影响,并对其缓释性能和抗紫外光降解进行了研究。结果表明:阿维菌素(AVM)均匀的混合在QL-SA载体中,主要以物理混合为主;最佳制备条件为:戊二醛为5%(以单体质量分数计)、药物加入量为1%(以单体质量分数计)、体系pH值为8.5,载药量和包封率分别达到1.36%和73.36%;阿维菌素缓释聚合物粒径符合正态分布,平均粒径为83.90 μm;阿维菌素缓释聚合物具有很好的缓释性能,在乙醇/水(体积比1:1)中释放30 h,累计释放率为88.97%;经8 h紫外光照射,阿维菌素原药中AVM残留量为6.24%,阿维菌素缓释聚合物中AVM残留量为37.75%,具有良好的抗紫外分解性能。     

多孔淀粉对森林浴香精的吸附及释放性能研究

本文采用多孔淀粉吸附法,制备具有一定缓释性能的香精缓释制剂。使用扫描电子显微镜观察其表面多孔并向内部延伸。150目多孔淀粉的平均饱和吸附率为0.785g/g。热重法测得在150℃之前,随着温度的升高,多孔淀粉缓释制剂失重速率加快,至170℃左右时,香精基本释放完全。紫外分光光度法得出,随着时间的延长,质量相等固体中香精含量c缓慢下降,释放速率也逐渐减小;吸附在多孔淀粉中的香精在初期表面阶段释放符合一级反应动力学,方程为logc=-0.03123t+0.9149(r2=0.96799);微孔阶段释放符合二级反应动力学,方程为1/c=0.0051t+0.1338(r2=0.95915)。     

河沙对污水中有机物吸附作用与动力学

为研究人工快速渗滤系统(CRI系统)的基质吸附有机物规律和性能,以河沙为对象,研究其对水溶液中COD的等温吸附特征,利用一级和准二级动力学模型对河沙吸附COD动力学过程进行了分析.结果表明,河沙对水溶液中COD的等温吸附特征符合非线性Langmuir方程,吸附强度因子K1=0.027 2为正值,说明反应在常温下可自发进行,最大COD吸附量为1 893.706 5 mg·kg-1.一级和准二级动力学两种模型标准偏差值r2都大于0.980 0,从标准偏差值角度判断都能较好地反映河沙对水溶液中COD的吸附动力学过程,但通过Langmuir方程相关参数以及试验校对得出一级动力学方程更适合反映河沙对水溶液中COD的吸附动力学过程,并导出该条件下河沙对水溶液中COD的平衡吸附量为1 750.335 5 mg·kg-1,而二级动力学模型误差较大.     

高效液相色谱荧光法同时检测黄瓜及土壤中的阿维菌素和甲维盐

利用高效液相色谱荧光法建立了阿维菌素和甲维盐在黄瓜中的多残留分析方法,样品用乙腈提取,直接离心净化后旋蒸浓缩,经三氟乙酸酐(TFAA)和N-甲基咪唑(NMIM)衍生化,过HPLC-FLD检测,结果显示:阿维菌素和甲维盐在0.01~2.0 mg/L标液范围内检测浓度与检测器响应峰面积呈良好线性关系,阿维菌素R2=0.9998,甲维盐R2=0.9993。在浓度为0.01~1.0 mg/kg的添加范围内,阿维菌素在黄瓜和土壤中平均回收率为87.12%~101.13%,RSD 2.38%~5.32%;甲维盐在黄瓜和土壤中平均回收率为85.88%~98.21%,RSD 2.44%~5.87%;本法前处理便捷,分析结果准确度高。     

Control of thermo reversible gelation of methylcellulose using polyethylene glycol and sodium chloride for sustained delivery of ophthalmic drug

The effect of molecular weight of polyethyleneglycol (PEG) and sodium chloride (NaCl) on the gelation temperature of methylcellulose (MC) was studied with the objective to develop a MC based formulation for sustained delivery of ophthalmic drug. The gelation temperature of 1% MC was 60 ± 0.40°C. It was found that the gelation temperature of MC was reduced with the addition of 10% PEG and extent of reduction of gelation temperature was depended on the molecular weight of PEG at same PEG concentration of 10%. The gelation temperature of MC was reduced by 10.4 to 5.9°C with the increasing molecular weight of PEG starting from 400 to 20,000 (M_n ) depending on the method of determination of gelation temperature. To reduce the gelation temperature of MC close to physiological temperature (37°C), 6% NaCl was added in the different MC‐PEG combinations containing different molecular weight of PEG. It was observed that the drug release time increased from 5 to 8 h with the increase in molecular weight of PEG from 400 to 20,000 (M_n ) and this was due to the maximum viscosity and gel strength of MC‐PEG20000‐NaCl ternary combination. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Influence of comonomer incorporation on morphology and thermal and mechanical properties of blends based upon isotactic metallocene–polypropene and random ethene/1‐butene copolymers

Blends of isotactic polypropene (i‐PP) with random ethene/1‐butene (EB) copolymers containing 10, 24, 48, 58, 62, 82, and 90 wt % 1‐butene were prepared in order to examine the influence of the EB molecular architecture on the morphology development as well as on the thermal and mechanical properties. Compatibility between i‐PP and EB increased with increasing 1‐butene content in EB to afford single‐phase blends at a 1‐butene content exceeding 82 wt %. The morphology was investigated using AFM and TEM. Improved compatibility accounted for enhanced EB dispersion and interfacial adhesion. Highly flexible as well as stiff blends with improved toughness were obtained. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 838–848, 1999     

Tuning alginate-bentonite microcapsule size and structure for the regulated release of P. putida Rs-198

In this study, different sizes of microcapsules with alginate and bentonite as natural macromolecular materials were prepared to investigate the release property of Pseudomonas putida Rs-198. The characteristics of three microcapsules were evaluated by SEM, FTIR, TG-DSC, XRD and wall thickness. The sizes of three microcapsules (MA, MB, and MC) were 1270.50, 831.79 and 42.52?μm, respectively. First, the encapsulation efficiency of three MA, MB, and MC microcapsules were 82.20%, 90.41%, and 85.84%, respectively. Second, the contact angles of MA and MB samples were similar, while smaller microcapsules MC have higher contact angle (85.05°), indicating poor hydrophilia and decreasing the swelling degrees. Third, the release cumulant of Rs-198 and macromolecule BSA linear stage was fitted to self-established mathematic model. Results show that the microcapsule size had a considerably positive effect on release detail. The large microcapsule possessed strong leak-tightness for Rs-198 as a slow-release microbial agent. Furthermore, the porosity of microcapsules determined their swelling and release and may affect bacterial growth and survival. In conclusion, the Rs-198 microcapsule with different sizes will be pertinently selected based on the characteristics of agricultural production requirements.     

A new approach to using submicron emeraldine-base polyaniline in corrosion-resistant epoxy coatings

The present work reports on a new approach to the preparation of special corrosion-resistant epoxy coatings. The aminic hardener of these coatings contained emeraldine-base polyaniline (EB-PANi). The aminic hardener was prepared by dispersion of EB-PANi in 3-(aminomethyl)-3,5,5-trimethylcyclohexan-1-amine employing sonication, centrifuging and submicron filtering methods. The state of dispersion and dissolution of these coating materials, during different stages of preparation, were characterized by optical microscopy and scanning electron microscopy. The corrosion resistances of resulting coatings were measured by electrochemical impedance spectroscopy (EIS) and salt spray methods. As little as 0.5% EB in initial mixture of EB-hardener compositions led to relatively better corrosion protection of resulting coating compared with neat resin coating. Presence of initial 2.5% of EB in the hardener and its processing through our approach resulted in the formulation of an epoxy coating with superior corrosion protection properties.     

Silicone acrylates through the hydrosilation of polyacryloyloxy functional monomers with copolymers of dimethyl and hydrogen methylsiloxanes

Silicone acrylates, as possible electron beam (EB) curable release coatings for paper, were prepared by the platinum-catalyzed hydrosilation of polyacryloyloxy functional monomers with copolymers of dimethylsiloxane and hydrogen methylsiloxane (PDMHMS). The hydrosilation of either 1,6-hexanediol diacrylate (HDDA) or trimethylolpropane triacrylate (TMPTA) with PDMHMS occurs to only one of the 2 or 3 available olefinic groups, respectively, as long as excess monomer is present. The amount of excess monomer needed to prevent gelation during hydrosilation or subsequent storage in excess of 1 month appears to be dependent on the hydrogen methylsiloxane content of the PDMHMS. A release coating having excellent cohesive and adhesive strength on paper was obtained by the EB curing of the product of hydrosilation of TMPTA with a PDMHMS containing 4 mol % hydrogen methylsiloxane at a dose-to-cure of 2 Mrad, but the aged release force was excessively high. The poor aged-release performance was likely due to dilution of the dimethylsiloxane content of the coating with excess monomer required to stabilize the silicone acrylate. © 1993 John Wiley & Sons, Inc.     

Flammability characteristics and performance of halogen‐free flame‐retarded polyoxymethylene based on phosphorus–nitrogen synergistic effects

The flammability characteristics and thermal stability of a novel halogen‐free flame‐retardant compounding system based on polyoxymethylene (POM) were studied, and a very effective flame retarding formulation for POM was developed from a combination of ammonium polyphosphate (APP), melamine cyanurate (MC), novolak, and dipentaerythritol. The decomposition behavior of POM compounds was evaluated by thermogravimetric analysis. The compound shows optimal flame retardancy with a limiting oxygen index of 52.8 and flammability rating of UL94 V‐0, when 27 wt % APP, 9 wt % MC, 4 wt % novolak, and 4 wt % dipentaerythritol are simultaneously incorporated into POM. The presence of novolak and dipentaerythritol as char‐forming agents results in a dense and compact multicellular char residue for the test bar after combustion, while Fourier transform infrared spectra confirm a characteristic phosphorous‐ and carbon‐rich char resulting from the APP/MC formulation. The pyrolysis–gas chromatography/mass spectrometry analysis indicates that highly flammable formaldehyde gas, the main pyrolysis product of POM, is annihilated by amide derivatives produced by the pyrolysis of MC, imparting better flame retardancy. The comprehensive flame‐retardant mechanisms based on phosphorus–nitrogen synergism promote the high flame retardancy of POM to reach the nonflammability of V‐0 rating. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

15％苄嘧·丙草胺泡腾片剂的研制及其药效试验

通过对原药及多种农药助剂和填料筛选试验和田间药效试验,从众多的助剂中筛选出15％苄嘧·丙草胺泡腾片剂的最佳配方,其配方为:苄嘧磺隆2％,丙草胺13％,润湿剂2.5％,分散剂4％,柠檬酸14.5％,碳酸氢钠16.5％,乳糖6％,硬脂酸镁2％,填料[m(白炭黑)∶m(膨润土)=1∶1]补充至100％.田间药效试验结果表明,...     

Bonding performance of melamine-urea-formaldehyde and phenol-resorcinol-formaldehyde adhesives in interior grade glulam

Wood moisture content (MC) affects the glued laminated beam (glulam) bonding strength. Selected adhesives were Phenol-Resorcinol-Formaldehyde (PRF) and Melamine-Urea-Formaldehyde (MUF) adhesives with 1, 1.5 and 2% (w/w) carboxymethyl cellulose (CMC) formic acid solutions. Douglas fir (pseudotsuga menziesii) from North America was used in the test. The bonding behavior of these adhesives with wood at 12 and 18% MC were investigated. The study focused on the effect of 18% MC on shear strength performance of MUF and PRF adhesives and optimizing the formula of CMC formic acid solution. Compressive shear strength of wood with MUF adhesive with 2% (w/w) formic acid solution at 12 and 18% MC stabilized at 10.6 and 10.0 MPa, respectively, which were 17 and 16% higher than that with PRF adhesive at the same condition. At 12–18% MC, MC had a little effect on bonding strength. However, 18% MC wood with PRF adhesive had 52.2% less initial strength increasing rate than that of 12% MC wood. 18% MC wood with MUF adhesives with 1, 1.5 and 2% (w/w) CMC formic acid solutions had 16.0, 15.5 and 27.0% less initial strength increasing rates than that of 12% MC wood, respectively. MUF adhesive using 2% CMC formic solution required the shortest press time at 12 and 18% MC about 1.6 and 2.7 h, respectively. The strength of PRF adhesive was significantly affected by wood MC and enough press time is essential for the proper bonding strength.