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

Preparation of Reversible Thermochromism Supramolecules of 4-Aminophenol-Modified Polydiacetylene

“…The shift of the absorption peak was considered as the conformational changes that the rotation of a methylene C-C bond pendants to the ene-yne backbone and the reduction in effective conjugation length due to the introduction of structural distortion upon thermal stimulus. Therefore, the HOMO-LUMO energy gap of perturbed PDA vesicles becomes wider, resulting in the color transition from blue to red [26]. It is believed that both side-chain order and head group interactions need to be responsible for the color transition of PDA material.…”

Liposome solubilization induced by complexation with dimeric β-cyclodextrin

“…The scientific appeal of polydiacetylene (PDA) liposomes is derived from their distinctive electronic and optical properties based on the extended p-electron delocalization along their backbones [1,2]. Variation of the effective p-conjugation lengths of the polymer backbones or conformational changes of the PDA unit induces color changes; thus, PDA undergoes a blue to red chromatic transition when thermal, mechanical, or chemical stimulus is applied [3]. Furthermore, the interesting fluorescence properties of PDA are evidenced by the lack of fluorescence of the initially polymerized blue-phase PDA, whereas the redphase PDA fluorescence strongly at 560 and 630 nm [4].…”

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.…”

“…A common route generally involves chemical modification of the PDA structure [10,14,15]. The increase in alkyl chain length promotes the dispersion interactions within the PDA assemblies, leading to the increase in color-transition temperature [7]. The substitution of polar head group affecting the dipolar and/or ionic interactions also provides similar results [10,51].…”