Nipaphat CharoenthaiThanutpon PattanatornchaiSumrit WacharasindhuMongkol SukwattanasinittRakchart TraipholNaresuan UniversityChulalongkorn UniversityMahidol University2018-05-032018-05-032011-08-15Journal of Colloid and Interface Science. Vol.360, No.2 (2011), 565-57310957103002197972-s2.0-79958782157https://repository.li.mahidol.ac.th/handle/20.500.14594/11676In this contribution, we report the relationship between molecular structures of polydiacetylene (PDA) vesicles, fabricated by using three monomers, 10,12-tricosadiynoic acid (TCDA), 10,12-pentacosadiynoic acid (PCDA) and N-(2-aminoethyl)pentacosa-10,12-diynamide (AEPCDA), and their color-transition behaviors. The modification of side chain length and head group of the PDA vesicles strongly affects the colorimetric response to temperature, ethanol and pH. A shorter side chain of poly(TCDA) yields weaker inter- and intra-chain dispersion interactions in the bilayers compared to the system of poly(PCDA), which in turn results in a faster color transition upon exposure to all stimuli. A change of head group in poly(AEPCDA) slightly reduces the transition temperature. Interestingly, the colorimetric response of poly(AEPCDA) vesicles to the addition of ethanol is found to occur in a two-step fashion while the response of poly(PCDA) vesicles takes place in a one-step process. The amount of ethanol required for inducing complete color-transition of poly(AEPCDA) vesicles is also much higher, about 87% v/v. The increase of pH to ~9 and ~10 causes a color-transition of poly(TCDA) and poly(PCDA) vesicles, respectively. The poly(AEPCDA) vesicles, on the other hand, change color upon decreasing pH to ~0. The colorimetric response also occurs in a multi-step fashion. These discrepancies are attributed to the architecture of surface layers of poly(AEPCDA), constituting amine and amide groups separated by ethyl linkers. © 2011 Elsevier Inc.Mahidol UniversityChemical EngineeringMaterials ScienceArticleSCOPUS10.1016/j.jcis.2011.04.109