%0 Journal Article
%K Nucleation
%K Heat transfer
%K Solidification
%K Melt
%K Crystallization
%K Differential scanning calorimetry
%K Gas-diffusion layer
%K Kinetics
%K Nonisothermal crystallization
%K Polyesters
%K Polymer crystallization
%A Thomas J Dursch
%A Monica A Ciontea
%A Gregory J Trigub
%A Clayton J Radke
%A Adam Z Weber
%B International Journal of Heat and Mass Transfer
%D 2013
%P 450 - 458
%R 10.1016/j.ijheatmasstransfer.2012.12.048
%T Pseudo-isothermal ice-crystallization kinetics in the gas-diffusion layer of a fuel cell from differential scanning calorimetry
%V 60
%8 05/2013
%! International Journal of Heat and Mass Transfer
%X <p>Non-isothermal ice-crystallization kinetics in the fibrous gas-diffusion layer (GDL) of a proton-exchange-membrane fuel cell is investigated using differential scanning calorimetry (DSC). Non-isothermal ice-crystallization rates and ice-crystallization temperatures are obtained from heat-flow measurements in a water-saturated commercial GDL at cooling rates of 2.5, 5, 10, and 25 K/min. Our previously developed isothermal ice-crystallization rate expression is extended to non-isothermal crystallization to predict ice-crystallization kinetics in a GDL at various cooling rates. Agreement between DSC experimental results and theory is good. Both show that as the cooling rate increases, ice-crystallization rates increase and crystallization temperatures decrease monotonically. Importantly, we find that the cooling rate during crystallization has a negligible effect on the crystallization rate when crystallization times are much faster than the time to decrease the sample temperature by the subcooling. Based on this finding, we propose a pseudo-isothermal method for obtaining non-isothermal crystallization kinetics using isothermal crystallization kinetics evaluated at the non-isothermal crystallization temperature.</p>