Breath-figure polymer films with local microporosity controlled via spatio-thermal templating

TY - GEN

T1 - Breath-figure polymer films with local microporosity controlled via spatio-thermal templating

AU - Mullan, M. J.

AU - Campbell, P. A.

PY - 2008

Y1 - 2008

N2 - Porous structures offer a vast range of important industrial applications. In the context of medicine, and specifically in the area of controlled drug delivery, spatial [and temporal] control over local porosity has a significant influence on net molecular flux through [membrane-based] controlled release platforms. Such systems may be formulated as oral, transdermal, or even implantable entities, and address chronic infusion needs covering such ailments as diabetes, cancer and hypertension [1]. In all the aforementioned situations, a facility to spatially control porosity could offer significant advantage, such as safer controlled release over extended durations. Here, we describe a novel route to engineering-in such flexibility within polymeric thin films by modifying spin-coating protocols to accommodate breath film patterning, that is, the spatially controlled condensation of pore forming droplets onto a liquid-polymer film. Upon film solidification, characterization via optical- and scanning probe microscopy revealed that local variations in porosity, as inferred from topographic measurements, could be effectively controlled through provision of an embossed vacuum holding chuck that effectively retains intimate thermal contact with the film substrate during forming. Parallel measurements using real time thermography support the hypothesis that porosity is controlled by local solvent evaporation rates.

AB - Porous structures offer a vast range of important industrial applications. In the context of medicine, and specifically in the area of controlled drug delivery, spatial [and temporal] control over local porosity has a significant influence on net molecular flux through [membrane-based] controlled release platforms. Such systems may be formulated as oral, transdermal, or even implantable entities, and address chronic infusion needs covering such ailments as diabetes, cancer and hypertension [1]. In all the aforementioned situations, a facility to spatially control porosity could offer significant advantage, such as safer controlled release over extended durations. Here, we describe a novel route to engineering-in such flexibility within polymeric thin films by modifying spin-coating protocols to accommodate breath film patterning, that is, the spatially controlled condensation of pore forming droplets onto a liquid-polymer film. Upon film solidification, characterization via optical- and scanning probe microscopy revealed that local variations in porosity, as inferred from topographic measurements, could be effectively controlled through provision of an embossed vacuum holding chuck that effectively retains intimate thermal contact with the film substrate during forming. Parallel measurements using real time thermography support the hypothesis that porosity is controlled by local solvent evaporation rates.

KW - polymer

KW - porous

KW - breath figure

KW - thermal imaging

KW - drug delivery

U2 - 10.1109/IEMBS.2008.4649711

DO - 10.1109/IEMBS.2008.4649711

M3 - Conference contribution

C2 - 19163214

SN - 978-1-4244-1814-5

SP - 2514

EP - 2517

BT - 2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Vols.1-8

PB - IEEE Computer Society

CY - NEW YORK

T2 - 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society

Y2 - 20 August 2008 through 25 August 2008

ER -