화학공학소재연구정보센터
Journal of Physical Chemistry B, Vol.118, No.26, 7450-7456, 2014
Amplification of Hofmeister Effect by Alcohols
We have demonstrated that Hofmeister effect can be amplified by adding alcohols to aqueous solutions. The lower critical solution temperature behavior of poly(N-isopropylacrylamide) has been employed as the model system to study the amplification of Hofmeister effect. The alcohols can more effectively amplify the Hofmeister effect following the series methanol < ethanol < 1-propanol < 2-propanol for the monohydric alcohols and following the series n-sorbitol approximate to xylitol approximate to meso-erythritol < glycerol < ethylene glycol < methanol for the polyhydric alcohols. Our study reveals that the relative extent of amplification of Hofmeister effect is determined by the stability of the water/alcohol complex, which is strongly dependent on the chemical structure of alcohols. The more stable solvent complex formed via stronger hydrogen bonds can more effectively differentiate the anions through the anion solvent complex interactions, resulting in a stronger amplification of Hofmeister effect. This study provides an alternative method to tune the relative strength of Hofmeister effect besides salt concentration.