Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (17): 1779-1784.DOI: 10.6023/A12050252 Previous Articles     Next Articles

Full Papers


陈栋栋a, 王林b, 孙俊奇a   

  1. a 吉林大学超分子结构与材料国家重点实验室 化学学院 长春 130012;
    b 西北农林科技大学 理学院应用化学系 杨凌 712100
  • 投稿日期:2012-05-28 发布日期:2012-07-09
  • 通讯作者: 孙俊奇
  • 基金资助:
    项目受国家自然科学基金(Nos. 20974037, 20921003)资助.

High Efficient Loading of Hydrophobic Molecules in Layer-by-Layer Assembled Microgel Films with the Assistance of Surfactant Micelles

Chen Dongdonga, Wang Linb, Sun Junqia   

  1. a State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China;
    b College of Science, Northwest A & F University, Yangling 712100, China
  • Received:2012-05-28 Published:2012-07-09
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Nos. 20974037, 20921003).

Layer-by-layer (LbL) assembly enables the fabrication of various kinds of functional films by sequential deposition of building blocks of polyelectrolytes, biomacromolecules, oligo-charged dyes, colloids, nanoparticles, polymeric complexes and so forth. However, water-insoluble organic species without necessary functional groups are difficult to be incorporated into multilayer films by conventional LbL assembly method. The present work aims to develop a facile method for efficient loading of hydrophobic molecules into LbL assembled films. To do so, PAH-D microgels, which are chemically cross-linked poly(allylamine hydrochloride) (PAH) and dextran, are LbL assembled with hyaluronic sodium (HA) to produce PAH-D/HA microgel films. Sodium dodecylsulfate (SDS) micelles are used as carriers to incorporate hydrophobic molecules of pyrene and spiropyran. The negatively charged SDS micelles loaded with hydrophobic molecules are successfully incorporated into the PAH-D/HA microgel films by a post-diffusion process, which produces transparent PAH-D microgel films with a large number of loaded pyrene and spiropyran molecules. Fluorescence emission spectra support that the hydrophobic molecules in PAH-D/HA films locate in the hydrophobic cores of SDS micelles. Stable loading of SDS micelles into PAH-D/HA films is achieved because of the strong electrostatic interaction between SDS micelles and protonated amine groups of PAH-D microgels. The high loading capacity of PAH-D/HA films toward SDS micelles encapsulated with hydrophobic molecules originates from the high swellability of the PAH-D/HA films and the abundance of unpaired amine groups in the PAH-D layers for binding of SDS micelles. The amount of hydrophobic molecules loaded into PAH-D/HA microgel films can be conveniently controlled by varying the deposition cycles of PAH-D/HA films and the concentration of hydrophobic molecules encapsulated in SDS micelles. The spiropyran-loaded PAH-D/HA microgel films show reversible photochromic property upon ultraviolet and visible light irradiation. The present work opens a cost-effective and general way to incorporate non-charged hydrophobic molecules into LbL assembled microgel films by using surfactant micelles as carriers.

Key words: layer-by-layer assembly, polymeric microgels, microgel films, surfactant micelles, polymeric films