Stable polydiacetylene/ZnO nanocomposites with two-steps reversible and irreversible thermochromism: The influence of strong surface anchoring

Roles of head group architecture and side chain length on colorimetric response of polydiacetylene vesicles to temperature, ethanol and pH

“…Polydiacetylene (PDA) is one of conjugated polymer that exhibits rather interesting chromic properties. It has been observed that PDA assemblies exhibit color-transition when subjected to various external stimuli including solvents (solvatochromism) [6][7][8][9], temperature (thermochromism) [10][11][12][13][14][15], pH [16][17][18][19], ions [20,21] and ligand-receptor interaction (affinochromism) [22][23][24][25][26][27][28][29][30]. This unique property renders PDAs to be utilized as an active material in various applications such as chemosensors [4,31,33], biosensors [23,[26][27][28][29][30][31][32], ion sensors [21,22,24,34], temperature sensors [14,35] and molecular switches [36].…”

“…PDA-based sensors can be prepared in different forms of organized structures such as Langmuir-Blodgett/Langmuir-Schaefer films [3,10,13], polyelectrolyte multilayered films [6,9,37] and assemblies dispersed in liquids [18][19][20][21][22][23][24]38,39]. Diacetylene (DA) monomers with polar head and long alkyl tail tend to spontaneously arrange into vesicular structure in aqueous medium.…”

“…The TCDA and PCDA monomers constitute the same carboxylic head but the length of TCDA alkyl tail is slightly shorter, affecting the strength of dispersion interactions within the bilayer of vesicles. Although previous studies already reported the colorimetric response of poly(PCDA) and poly(TCDA) vesicles to external stimuli [8,10,18,[51][52][53][54][55][56][57][58], detailed comparative study to reveal the role of dispersion interactions was not performed. The change from carboxylic group of PCDA to amine and amide groups of AEPCDA affects the strength of hydrogen bonding at the surface of vesicles.…”

Controlling the reversible thermochromism of polydiacetylene/zinc oxide nanocomposites by varying alkyl chain length

“…It has been observed that the PDA-based materials exhibit blue/purple, blue/red, or blue/orange color transitions when exposed to various external stimuli such as solvents (solvatochromism) [1][2][3][4][5][6][7][8][9], temperature (thermochromism) [10][11][12][13][14][15][16][17][18][19][20][21][22], pH [23][24][25][26][27][28][29], ions [30][31][32][33][34], biomolecules [35][36][37][38][39][40][41][42][43], and other chemicals [44,45]. Therefore, the development of sensing technologies based on this material has become rather attractive.…”

“…The thermochromic behavior of PDAs with carboxylic head group is normally an irreversible process [7,10,22]. This mainly arises from the relatively weak inter-and intrachain interactions within the system.…”