Deliberately Designed Processes to Physically Tether the Carboxyl Groups of Poly(pentacosadiynoic acid) to a Poly(vinyl alcohol) Glassy Matrix to Make Poly(pentacosadiynoic acid) Thermochromically Rev

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• 作者：Juan Guo ; Lei Zhu ; Ming Jiang ; Daoyong Chen
• 刊名：Langmuir
• 出版年：2011
• 出版时间：June 7, 2011
• 年：2011
• 卷：27
• 期：11
• 页码：6651-6660
• 全文大小：1105K
• 年卷期：v.27,no.11(June 7, 2011)
• ISSN：1520-5827

文摘

In this article, we demonstrate that by tethering carboxyl groups of poly(10,12-pentacosadiynoic acid) (PDA) to a poly(vinyl alcohol) (PVA) matrix, PDA, which is irreversible in its pure form, becomes reversible in the thermochromism. The tethering is realized by simple but deliberately designed processes: (1) Disperse the commercially available monomer 10,12-pentacosadiynoic acid (DA) nanocrystals in a PVA aqueous solution by the 鈥淣CCM鈥?method invented in our laboratory. (2) Anneal and dry the mixture solution at a temperature higher than the melting point of pure DA crystal. (3) Polymerize the as-annealed DA/PVA blend films by UV irradiation. After the polymerization, PDA/PVA films with completely reversible thermochromism are obtained. The reversible PDA/PVA films can be easily dissolved in water, leading to water-dispersible nanoaggregates with the reversibility. Blends of PDA with other water-soluble polymers such as poly(ethylene oxide) (PEO), poly(acrylic acid) (PAA) and poly(allyamine) (PAM), were prepared respectively, by the same processes and under the same conditions. It is found that all these nanocomposites are irreversible or partially reversible in the thermochromism; either the relatively low glassy transition temperature of the polymer matrix (in the case of PEO) or the partial ionization nature of the polymer (in the cases of PAA and PAM) is responsible for the irreversibility or the partial reversibility.