The combination of enzymolysis of compound enzyme, oxidation of sodium hypochlorite, and cationic etherification of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTMA) was selected for the functionalization of rice starch (RS) to better raise the performances. The results showed that the oxidation and etherification could improve the acid and alkali resistance of RS, and enhanced its thermal stability. The crystalline structure of RS was an A-type, the enzymolysis, oxidation, and etherification did not change the structural type, while the crystallinity degree of RS derivatives was all reduced. The enzymolysis, oxidation, and etherification altered the pasting properties of RS, and could effectively decrease the setback and breakdown of RS. The oxidation of sodium hypochlorite not only damaged RS particles containing no micropores, but also destroyed the particles containing the micropores. The enzymolysis and oxidation more seriously destroyed the crystalline region than cationic etherification. The oxidation could increase the enthalpy change of RS, whereas the enzymolysis and etherification decreased its enthalpy change. In addition, the enzymolysis and oxidation could lead to the evident increase in average size of RS. The cationic etherification was able to improve the adsorption of Cu2+ on RS, whereas the low oxidation could only slightly ameliorate the adsorption of Cu2+ . PRACTICAL APPLICATION: Cationic oxidized microporous rice starch as an adsorbent, slow-release agent, and flocculant will be well used in food, medicine, pesticide, papermaking, waste water treatment, and so on owing to its abundant micropores, anionic groups, and cationic groups as well as small particle size and narrow size range.

中文翻译：

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阳离子氧化微孔大米淀粉的制备、表征和性能

选择复合酶酶解、次氯酸钠氧化和3-氯-2-羟丙基三甲基氯化铵（CHPTMA）阳离子醚化相结合的方法对大米淀粉（RS）进行功能化，以更好地提高性能。结果表明，氧化和醚化可以提高RS的耐酸碱性，增强其热稳定性。RS的晶体结构为A型，酶解、氧化、醚化反应未改变结构类型，而RS衍生物的结晶度均降低。酶解、氧化和醚化改变了 RS 的糊化性质，可以有效减少 RS 的挫折和分解。次氯酸钠的氧化不仅破坏了不含微孔的 RS 颗粒，但也破坏了含有微孔的颗粒。酶解和氧化比阳离子醚化更严重地破坏了结晶区域。氧化可以增加RS的焓变，而酶解和醚化降低其焓变。此外，酶解和氧化可能导致 RS 平均大小的明显增加。阳离子醚化能够提高Cu2+在RS上的吸附，而低氧化只能略微改善Cu2+的吸附。实际应用：阳离子氧化微孔大米淀粉作为吸附剂、缓释剂和絮凝剂，由于其丰富的微孔、阴离子基团、