Synthesis and characterization of molecularly imprinted polymers and their application in preconcentrators for gas phase sensors.

摘要

Various of molecularly imprinted polymers were synthesized by different protocols. Piezoelectric quartz crystals coated with molecularly imprinted polymers were prepared to detect small organic vapors. Hydroquinone (HQ) and Phenol (P) have been used as non-covalent bound templates in order to generate shape-selectivity cavities in the polymer matrix. The recognition film was immobilized on the crystal surface via a pre-coated Poly(isobutylene) layer. The selective behaviors of the imprinted polymer films were studied by their steady-state response to various kinds of small organic vapors. The partition coefficients of polymers toward vapors were evaluated. The imprinted polymers exhibit high sensitivity and selectivity toward organic vapors as toluene and benzene, which are structurally related to the templates. Imprinted polymers prepared by different synthesis schemes were compared. The influence of template concentration and the polymer components was also investigated. The adsorption capacity of molecularly imprinted polymers was characterized and compared by breakthrough studies. From our results, molecularly imprinted polymer is promising for the development of selective piezoelectric sensor for organic vapor detection.;Different types of preconcentrator devices capable of pre-concentrating organic vapors at low ppm levels were fabricated and described. The target organic vapors were enriched onto a small bed of adsorbents and subsequently released by thermal desorption scheme. Solid adsorbents (Tenax GR, TA and molecularly imprinted polymers) were evaluated for possible use in a preconcentrator. Approximate preconcentration factor in the range of several thousand can be achieved by using the block polymer imprinted with hydroquinone.