Freezing of nanodroplets: Phase transition of organic liquids confined in nanopores studied by positron annihilation spectroscopy
Behavior of solids and liquids confined in nano domain has great relevance in fundamental research as well as applications in nanotribology, nanofabrication, membrane separation, interfacial adhesion and lubrication. In this work, we have studied phase transition behavior of different organic liquids confined in nanopores of ZSM-5 zeolite and silica using temperature dependent positron annihilation Doppler broadening and lifetime spectroscopy. It is observed that the freezing and melting properties of liquids confined in nanopores are different from their bulk behavior. The liquid molecules (isopropanol) that feel more attractive interaction with the pore wall show an increase in freezing temperature. Similarly, a liquid like benzene which is weakly attractive with pore wall as compared to its solid phase show a decrease in its freezing point under confinement. The confining pore diameters are in the range of 10-60 (A). It was observed that the shift in phase transition temperature does not follow classical Gibbs-Thomson relation.
Positron annihilation phase transition nanodroplet nanopore confinement freezing
D.Dutta S.K.Sharma P.Maheshwari K.Sudarshan P.K.Pujari
Radiochemistry Division,Bhabha Atomic Research Centre,Trombay,Mumbai-400 085 India
国际会议
第九届国际正电子与正电子素国际会议(9th International Workshop on Positron and Positronium Chemistry)(PPC–9)
武汉
英文
218-222
2008-05-11（万方平台首次上网日期，不代表论文的发表时间）