Nano-dispersion of TEMPO-oxidized cellulose/aliphatic amine salts in isopropyl alcohol
Nano-dispersion of TEMPO-oxidized cellulose/aliphatic amine salts in isopropyl alcohol
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DOI：
10.1007/s10570-011-9648-2
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发表时间：
2012-04-01
期刊：
影响因子：
5.7
通讯作者：
Isogai, Akira
中科院分区：
文献类型：
--
作者：
Fujisawa, Shuji;Saito, Tsuguyuki;Isogai, Akira
在水-异丙醇混合物中，通过羧基/胺盐的形成，将伯脂肪胺引入到大部分（约95%）密集存在于tempo氧化纤维素纳米纤维（TOCN）表面的羧基中。引入TOCN的烷基链长碳数随n-癸基、n-十二烷基、n-十四烷基、n-十六烷基和n-十八烷基胺而变化。当正十二烷基、正十四烷基和正十六烷基胺中和羧基时，ton - cooh /胺盐通过超声波处理在单个纳米纤维水平上分散在纯异丙醇（IPA）中，并在交叉偏振光间观察得到稳定透明的IPA分散体。采用浇铸和干燥法制备了正十二胺处理的TOCN-COOH （TOCN-COOH/ c -12胺盐）柔性、高透明、表面疏水的自立膜。然而，通过胺盐形成在TOCN表面引入丰富的长烷基链，导致薄膜的机械和氧屏障性能明显低于TOCN- coona薄膜。
Primary aliphatic amines were introduced into most of (> 95%) carboxyl groups densely present on the TEMPO-oxidized cellulose nanofibril (TOCN) surfaces via carboxyl/amine salt formation in a water-isopropyl alcohol mixture. The carbon number of alkyl chain lengths introduced into TOCN varied using n-decyl-, n-dodecyl, n-tetradecyl-, n-hexadecyl- and n-octadecyl-amines. When n-dodecyl-, n-tetradecyl- and n-hexadecyl-amines were used for neutralization of carboxyl groups, the TOCN-COOH/amine salts were dispersed at the individual nanofibril level in pure isopropyl alcohol (IPA) by ultrasonication treatment, and gave stable and transparent IPA dispersions with birefringence when observed between cross polarizers. Flexible, highly transparent and surface-hydrophobic self-standing films of n-dodecylamine-treated TOCN-COOH (TOCN-COOH/C-12-amine salt) were prepared by casting and drying of the dispersion. However, the introduction of abundant long-alkyl chains on the TOCN surfaces via the amine salt formation resulted in clearly lower mechanical and oxygen barrier properties of the films than those of TOCN-COONa films.