Conformational Stability of Poly (N-Isopropylacrylamide) Anchored on the Surface of Gold Nanoparticles

Materials

Xuefan Gu¹  Caixia Zhang²  Runmei Li²  Zhuorui Wang²  Chen Wang²  Daodao Hu²  Cong Cheng²  Xinyue Liang³ 

[1] College of Chemistry and Chemical Engineering, Xi’an Shiyou University, Xi’an 710065, China;Engineering Research Center of Historical and Cultural Heritage Protection, Ministry of Education, School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062, China;Institute of Industrial Hygiene of Ordnance Industry, Xi’an 710065, China;

关键词: gold nanoparticles;    PNIPAM;    immobilized PNIPAM;    failed thermo-sensitivity;   

DOI  :  10.3390/ma14020443

来源: DOAJ

【 摘 要 】

To verify the temperature sensitive failure of poly (N-isopropylacrylamide) (PNIPAM) anchored on the surface of gold nanoparticles (AuNPs), the UV-Vis spectra with temperature variations of the following aqueous solutions respectively containing AuNPs-PNIPAM, Au-PNIPAM/PNIPAM, PNIPAM, in different media (including salt, ethanol, HCl and cetyltrimethylammoniumbromide (CTAB)), were systematically determined. The results indicated that the UV-Vis spectrum of AuNPs-PNIPAM suspension hardly changed even above the Lower Critical Solution Temperature (LCST) of PNIPAM, but that of Au-PNIPAM/PNIPAM sharply increased only in absorbance intensity. A possible mechanism of the failed temperature sensitivity of PNIPAM anchored on the surface of AuNPs was proposed. Being different from free PNIPAM molecules, a strong interaction exists among PNIPAM molecules anchored on the surface of AuNPs, restraining the change in conformation of PNIPAM. The temperature sensitivity of Au-PNIPAM/PNIPAM originates from the free PNIPAM molecules rather than the anchored PNIPAM one. The changing electrostatic interaction could effectively regulate the aggregation behavior of AuNPs-PNIPAM and enhance its sensitivity to temperature.

【 授权许可】

Unknown