摘要:

AbstractWater‐soluble polydiacetylenes, RC—CC—CR, where R is either (CH2)3,4OCONHCH2COOK or (CH2)3,4COOK, undergo visual (yellow ↔ red or purple) reversible conformational (nonplanar ↔ planar) transitions by varying the pH of the solution as well as by the addition of different monovalent electrolytes, such as KCl and LiCl. Polyvalent cations such as Ca2+cause precipitation of the polymer due to crosslinking. The conformational changes caused by the variations in pHs can be viewed as a gradual ion exchange process, for example, K+is exchanged with H+or vice versa. The transition phenomena were studied by visible absorption spectroscopy. The broadest spectral change (465 nm ↔ 575 nm) occurred when the pH of the solution was changed from 9 to 2. The spectral shifts displayed by the additions of electrolytes were rather narrow (465 nm ↔ 515 nm), the corresponding color change being yellow ↔ red only. The luminescence properties (fluorescence only) of these water‐soluble polydiacetylenes were also studied. The fluorescence is pH dependent, being observed only at relatively higher pHs. Both absorption and emission spectra revealed some anomalous phenomena for which explanations are provided throug

ISSN:0360-8905    

DOI:10.1002/polc.5070710123

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

ISSN:0360-8905    

DOI:10.1002/polc.5070710124

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

ISSN:0360-8905    

DOI:10.1002/polc.5070710102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY