Preparation of micelles having a UV absorbent at their coronas using a 'non-amphiphilic' di-block co-polymer

Authors: Yoshida, Eri; Ohta, Masayo

Source: Designed Monomers & Polymers, Volume 8, Number 5, 2005 , pp. 501-513(13)

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Abstract:

Micelles having UV absorbents at their coronas were prepared using a non-amphiphilic block co-polymer. A poly(vinylphenol)-block-poly{4-(2-hydroxybenzophenoxymethyl)styrene-co-styrene} di-block co-polymer (PVPh-b-P(HBS-co-St)) shows no self-assembly in 1,4-dioxane because this solvent is non-selective to the co-polymer. Light scattering studies demonstrated that the co-polymer showed micellization in the solvent in the presence of ,-diamine, producing micelles with an UV absorbent at the coronas. The critical micelle concentration (cmc) and the aggregation number of the micelles were dependent on the co-polymer concentration and structure of the diamine. The co-polymer at a lower co-polymer concentration showed a higher cmc and produced micelles with a smaller aggregation number. The long methylene chain of the diamine and the intramolecular hydrogen bonding in the diamine prevented the co-polymer from aggregating into micelles. The micellar size was almost independent of the co-polymer concentration and the diamine structure. The mixed micellization of PVPh-b-P(HBS-co-St) and a di-block co-polymer having azo dyes produced the micelles with the UV absorbents and the dyes at the coronas. The molar ratio of the UV absorbent to the dye in the mixed micelles and the aggregation number of the micelles were manipulated by choice of the weight ratio of the co-polymers.

Keywords: NON-AMPHIPHILIC DI-BLOCK CO-POLYMER; POLY(VINYLPHENOL)-BLOCK-POLY{4-(2-HYDROXYBENZOPHENOXYMETHYL)STYRENE-CO-STYRENE}; UV ABSORBENT; MICELLES; ALPHA; OMEGA-DIAMINE; HYDRODYNAMIC RADIUS; AGGREGATION NUMBER

Document Type: Research article

DOI: http://dx.doi.org/10.1163/1568555054937908

Publication date: 2005-11-01