Abstract:
Water under nano-confinement is different from normal water. It is relevant to life and geoscience because much of the hydration phenomenon in nature occurs in narrowly confined water. Studying confined water will help one to understand the physicochemical effect of water and its interaction with solutes in crowded environment. Mesoporous silica materials with uniform pore size will be the confining media in our study. By using neutron and X-ray scattering techniques, we studied the density and diffusion of water under nanoconfinement. By confining solutes, solubility of a hydrophobic molecule such as Xe in water under nanoconfinement will impact several related problems, (a) solubility of methane in water within nanopores of rock under fracking condition, (b) understanding how hydrophobic effect would be changed in confined water, (c) how protein hydration would change under confinement.
We studied hydration behavior of Xe in water confined in mesoporous silica using Xe-NMR chemical shifts. Temperature change of the signal allows us to determine the enthalpy of hydration. It was found that in pore confined water, the hydration of Xe is more energetically favorable than in bulk water. The increased solubility of Xe in nanopore is in the same trend with computer simulation results of confined methane.
Next, we employed mesoporous silica of matching pore sizes to confine lysozyme in order to mimic enzyme in a crowded environment. The stability and activity of lysozyme immobilized in mesoporous silica nanoparticle (MSN) of various pore sizes were studied and correlated to spectroscopic data of the immobilized enzyme. It was found that the activity of the lysozyme immobilized in the 5.6 nm mesopores of MSNs was higher than those of native enzymes. The enhanced activity was attributed to subtle change in hydration of lysozyme due to increased stability of hydrophobic solvation.
Brief Bio:
男；民39年3月15日；台灣省基隆市
現職：國立臺灣大學化學系教授(民67-)。
學歷：國立臺灣大學化學系學士(民55-59)、美國華盛頓大學化學博士(民60-64)。
經歷：美國奧勒崗大學博士後研究(民64-66)、美國普渡大學博士後研究(民66-67)、臺灣大學化學系副教授(民67-71)、臺灣大學化學系教授 (民71-)、比利時布魯塞爾自由大學訪問學者(民72-73) 、台灣教育改革審議委員會委員(民82-84)、臺灣大學化學系主任(民93-96)、遠哲科學教育基金會董事(民87-100)、天下文化出版顧問(民 80-) 、國科會化學審議會學門召集人(民88-90)、奈米科技國家型計畫顧問(民91-96)、國家科學委員會副主任委員(民101-103)、國立台灣大學 講座教授(民103-)、中央研究院院士(民105)、亞洲太平洋催化聯盟主席(民105)。