壳聚糖纳米复合涂膜的研究

【作者】 刘晶；

【导师】 王明力；

【作者基本信息】 贵州大学 ， 食品科学， 2007， 硕士

【摘要】 纳米复合涂膜农药新剂型是以纳米二氧化钛（纳米TiO₂）和壳聚糖（CTG）为主要成分，与农药原药充分反应，喷施后，在果蔬作物上形成一层薄薄的膜，这种剂型的农药能减少吹飘、蒸发、流失，提高农药的粘附力，有助于内吸性农药渗透，改善承受雨淋的能力，是一种长效、安全、经济和方便的农药新剂型。本论文研究了纳米TiO₂粉体改性的优化条件，并将改性后的粉体加入到农药／壳聚糖溶液中制得壳聚糖-TiO₂-农药（CTG-TiO₂-P）复合膜，通过对其力学性能及抗菌效果等方面的检测，制得涂膜型农药新剂型。纳米TiO₂粉体经改性后，通过对亲油化度的测定，从三种改性剂中选取最佳改性剂——月桂酸钠，并对其用量、最佳反应条件进行优化。纳米TiO₂用表面改性剂月桂酸钠改性后，以溶液共混法制备了CTS-TiO₂-P复合膜，用FTIR和TEM表征了其结构与形态，并在粘度、厚度、水蒸气透过率、透光率、透气性、力学性能和抑菌性能等方面与壳聚糖简单膜进行了比较。实验结果表明，复合膜中，壳聚糖与TiO₂微粒间存在较强的氢键作用，从而使TiO₂和壳聚糖之间有很好的界面作用。适量TiO₂的加入，可使壳聚糖的力学性能得到改善（拉伸强度提高15.0％，断裂伸长率提高27.2％，直角撕裂强度提高35.6％），抑菌性能得到加强。壳聚糖-TiO₂（CTS-TiO₂）复合膜和CTS-TiO₂-P复合膜经抗菌检测表明对细菌具有良好的抗菌能力，如革兰氏阴性菌大肠杆菌、革兰氏阳性菌枯草芽孢杆菌和都柏林沙门氏菌；对真菌也有一定的抗菌效果，如酵母和青霉；单纯的农药水溶液对以上细菌及真菌的抗菌效果不明显；同时CTS-TiO₂复合膜对植物致病菌的抗菌效果差于CTS-TiO₂-P复合膜，因此，可以得出结论，壳聚糖和纳米TiO₂的加入，增强了农药的抗菌效果，同时以纳米TiO₂和壳聚糖为主要成分的纳米复合涂膜作为农药新剂型是可行和有效的。更多还原

【Abstract】 The new pesticide formulation of nanometer compound membrane is take nano-TiO₂ and the chitosan as the principal constituent, reacted with the original pesticide completely, forms a thin membrane on the fruits and vegetables after spurting. This kind of dosage-form of pesticide can reduce blow flutter、evaporate、drain, enhance the adhesion and infiltration of the pesticide, , improve the ability of the water resistance. It is a sort of effective, secure, economical and convenient new pesticide formulation.The paper studies the optimal condition of modifying nano-TiO₂ powder, and the compound membrane of chitosan /TiO₂ and the pesticide with the modifying nano-TiO₂ powder is gained, and proving with the researches of mechanical properties test and antibacterial activity test.According to the researches of lipophilic degree, choose the best modified pharmaceutical of sodium laurate from three kinds of modified pharmaceutical, and optimize its dosage and the best reaction condition.The chitosan/modifying nano-TiO₂ and pesticide compound membrane is prepared with solution method. The configuration of membrane is ascertained by FTIR and TEM. And compare with the membrane of chitosan by measuring the viscosity, thickness, percent water absorption, optical transmittance, the measurements of mechanical properties and antibacterial activity. It was found that there was hydrogen bonding interactions between chitosan and nano-TiO₂. So the mechanical properties is enhanced, （longitudinal strength: 15.0%, break elongation ratio: 27.2%, right angle peel strength: 35.6%）, and the antibacterial activity is also enhanced.According to the researches of antimicrobial test, it is found that the antibacterial activity of chitosan/nano-TiO₂ compound membrane and chitosan/nano-TiO₂ with pesticide compound membrane is good, such as Escherichia coli of Gram-Negative Bacteria, Bacillus subtilis and Salmonella Dublin of Gram-Positive Bacteria; Also have certain antibiosis effect on fungi, for example, yeast and penicillium; the antibacterial activity on the above-mentioned bacteria and fungi of simple pesticide that aqueous solution is not good; and the antibacterial activity on agriculture pathogen of chitosan / nano-TiO₂ compound membrane is worse than chitosan / nano-TiO₂ with agricultural chemicals compound membrane. The conclusion is that, the chitosan and nano-TiO₂ can strengthen the antibacterial result of pesticide, enhance the mechanics performance of the chitosan membrane, prolong the effect of pesticide.更多还原