ABSTRACT
This work presents a simple method to generate ordered chromophore/dispersant nanoarrays through a pore-filling process for a nanoporous polymer template to enhance chromophore luminescence. Fluorescence results combining with the morphological evolution examined by scanning probe microscopy reveal that the enhanced luminescence intensity reaches the maximum intensity as the nanopores of the template are completely filled by the chromophore/dispersant mixture. The variation is attributed to nanoscale spatial effect on the enhanced mixing efficiency of chromophore and dispersant, that is, the alleviation of self-quenching problem, as evidenced by the results of attenuated total reflection Fourier transform IR spectroscopy combining with grazing incident wide-angle X-ray diffraction. The enhanced luminescence of the chromophore/dispersant nanoarrays driven by the nanoscale spatial effect is highly promising for use in designing luminescent nanodevices.
Subject(s)
Luminescence , Nanostructures/chemistry , Nanotechnology , Polymers/chemistry , Pyrenes/chemistry , Luminescent Measurements , Particle Size , Porosity , Surface PropertiesABSTRACT
Nanoporous thin-film samples, fabricated from degradable block copolymers, polystyrene-b-poly(l-lactide) (PS-PLLA), were utilized as templates for the formation of ordered nanoarrays. This work elucidates the feasibility of using such nanoporous PS templates as coatings on implantable devices for drug delivery through pore-filling sirolimus. Specific pore-filling process was adopted to increase loading efficiency by exploiting the capillary force associated with the tunable wetting property of the sirolimus solution. After the pore-filling process, sirolimus-loaded cylindrical and lamellar nanoarrays can be obtained. A comparison with those of macroscale templates indicates that the developed nanoporous templates can successfully entrap the loaded drug in nanoscale pores, markedly increasing the duration of drug delivery. As a result, the size, geometry, and depth of the nanoscale pores of the nanoporous templates can be readily controlled to regulate the drug release profiles.
