基于模板激活分子印迹策略的棉酚识别和吸附功能材料的合成和结构性能研究

The highly toxic gossypol in cotton seed is a big hurdle for its practical application. Development of energy efficient and environment benign process to prepare gossypol free cotton seed protein is paramount important. In order to achieve this goal, the template activated molecular imprinting strategy are proposed and developed to synthesize functional materials featuring high affinity and specificity for gossypol. Based on the principle of molecular recognition, the functional group which can specifically recognize gossypol is designed and the functional monomers are prepared. The molecularly imprinted polymers using gossypol as template are synthesized which feature high affinity and high specificity binding sites for gossypol. The functional monomers with tendency to form self-aggregates are designed using urea functionality via intra-molecular hydrogen bonding. Taking advantage of functional monomer self-aggregation, template activated molecular imprinting strategy are designed and achieved. Template activated molecular imprinting strategy use functional monomers not only with functional group specifically targeted to template molecule but also bearing functionality which can form self-aggregated structure. This design can significantly reduce the formation of non-specific binding sites in molecular imprinted polymers by functional monomer self-aggregation. molecular imprinted polymers made with this strategy can dramatically increase the affinity, specificity and selectivity for targeted template molecule. Control functional monomer are fixed onto the surface of silica gel to evaluate the molecular imprinting effect. Another control molecular imprinted polymer is made using functional monomer bearing the same recognition group for gossypol but without self-aggregation to evaluate the effectiveness of the template activated molecular imprinting strategy. In order to establish the structure-property relationship, key parameters such as different functional groups, types of crosslinkers, the ratio of functional monomer, template molecule and crosslinker, degree of crosslinking, solvent are systematically studied. It is proposed that the template activated molecular imprinting strategy will greatly facilitate the design of functional material with extremely high affinity and specificity by reducing the formation of non-specific binding sites. This type material holds great potential for the recognition and absorption of gossypol.

由于棉籽中含有大量对人畜有毒的棉酚, 严重限制了其应用价值。开发节能环保、高效的棉酚识别和吸附材料，对棉籽资源的利用意义重大。本研究课题，提出并设计了模板激活分子印迹策略。采用基于分子识别的理念，筛选和合成出对棉酚具有特异性识别的官能团和单体分子，通过分子印迹的方法合成具有特异性识别位点的分子印迹有机功能材料。通过分子间氢键作用，设计合成对棉酚具有特异性吸附并且具有自聚集效应的单体分子。通过单体分子的自聚集效应，实现模板激活分子印迹策略。模板激活分子印迹策略能够有效减少分子印迹聚合物中非特异性识别位点的数量。增强分子印迹聚合物对棉酚的识别专一性和吸附能力。采用系列对照单体分子，考察和评价分子印迹策略和模板激活分子印迹策略的的有效性。考察关键参数，确定最佳的合成条件和工艺。通过模板激活分子印迹策略，合成对棉酚具有特异性识别和吸附的功能材料，为脱酚棉籽资源利用提供关键理论和技术支撑。

为开发节能环保、高效的棉酚识别和吸附材料，提出了模板激活分子印迹策略。采用基于分子识别的理念，合成出了对棉酚具有特异性识别官能团的单体分子，具体包括脂肪链单脲基或双脲基功能单体分子；含脲基官能团的苯乙烯类功能单体分子；以及以氮为中心的多脲基三脚架型功能单体分子。基于所合成的功能单体分子间脲基的氢键作用，实现了对棉酚的特异性吸附及功能单体分子的自聚集效应，采用合成的功能单体分子，合成了对棉酚及与棉酚结构相似的含酚羟基化合物洛克沙砷、三氯生、三氯卡班、鞣花酸等具有特异性识别的分子印迹有机功能材料。采用本体聚合法、溶胶-凝胶表面印迹法合成了棉酚分子印迹聚合物（MIP），系统地考察了硅胶载体的尺寸和形状对溶胶-凝胶法制备棉酚表面分子印迹聚合物性能的影响。结果显示：模板激活分子印迹策略能够有效减少分子印迹聚合物中的非特异性识别位点，从而增强分子印迹聚合物对模板分子的识别专一性和吸附能力。考察了合成分子印迹聚合物的关键参数，优化并确定了最佳的合成条件和工艺。通过静态吸附实验评价了分子印迹聚合物对棉酚的吸附性能。对吸附实验数据进行非线性拟合，结果显示棉酚分子印迹聚合物对棉酚的吸附动力学较好地符合准二级动力学模型，所合成的分子印迹聚合物，对棉酚的最大吸附容量为632 mg/g。与非印迹聚合物（NIP）相比，棉酚分子印迹聚合物对模板分子棉酚具有很好的选择性。而且，该材料在重复利用5次之后，对棉酚的吸附容量仍能保持在90%以上，表明该材料可以多次重复使用。以上结果显示制备得到的棉酚分子印迹聚合物是一种很有应用潜力的功能材料，能够实现对棉酚的选择性吸附。同时以棉花、棉花短绒、棉籽壳为原料，制备了功能型碳纤维和氮掺杂多孔碳材料。由于实验所需要高纯度的游离棉酚，价格极其昂贵，因此本课题发明了一种以醋酸棉酚为原料制备游离棉酚的方法，申报并获得了国家发明专利授权，为后续棉酚资源的开发利用打下了基础。模板激活分子印迹策略，为分子印迹聚合物的设计提供了一种新的方法。