The morphological and wetting properties of chitosan films containing dansyl derivatives have been investigated. By means of dynamic contact angle measurements, we study the modification of surface properties of chitosan-based films due to UV irradiation. The results were analyzed in the light of the molecular-kinetic theory which describes the wetting phenomena in terms of the statistical dynamics for the displacement of liquid molecules in a solid substrate. Our results show that the immobilization of dansyl groups in the chitosan backbone leads to a pronounced enhancement of the UV sensitivity of polymeric films. (C) 2012 Elsevier Inc. All rights reserved.