Phase Behavior Of 1-Hexadecanol And 1-Octadecanol Under Nanocofinement

Under the Nanoconfinement,there has a series of remarkable effect in the phase behavior of alcohol because of the channel structures,small size effect,and interface effect in porous materials,When the alcohol in the hole,its phase-transition temperature,enthalpy of phase change and the existence are changing along with the aperture size and the effect of wall of the hole.during the experiment,we are using some of the porous materials,such as Silica gel?SG?,porous glass?CPG?and SBA-15,and making organic liquid adsorption with porous materials by physical method,which will produce some interaction model between organic molecule and the wall of the wall in feeble,secondary and strong strength.The basic means of detection used for DSC calorimeter method at low temperature,For the alcohol?s melting point,freezing point,phase change enthalpy during the obvious changing regularity in the pore sizes of 12-300 nm at different pore structure and interaction models by low temperature DSC method.Finally,By XRD ray scanning as auxiliary methods.According to the standard spectral line analysis the crystal shape of alkanol,estimating the relationship with the porous material size and its thermodynamic properties under the action of interface.This study may provide the thermodynamic basis in the preparation of nano materials,transport of nano-drug and understanding the property of the ilw dimensional fluid.The main work of this experiment are as follows:?1?By the quality of mixing ratio to make the alcohol and porous materials mixed fully by means of the method of melt-solution,And then placed within the drum wind drying oven,in which temperature is higher than the alcohol?s melting point,And then the alcohol internal melt adsorption into porous materials.and prepared the phase change materials.?2?The phase change materials?s thermodynamic properties in the nomal state and after the adsorption of different size in the internal hole-channels are can be observed by using using differential scanning calorimeter instrument?DSC?.And then,we can noticed the phasechange rules in the process of heating up and cooling,and explored the difference of change with the aperture.Result is that accompanying with the decrease of the aperture,the phase change temperature and phase change enthalpy of the alcohol are showed decreasing trend.?3?The changes in spectrum are drawn by using the differential scanning calorimeter instrument?DSC?and X-Ray Powder Diffraction?XRD?,Given the results of the design analysis,Although in the large aperture of CPG?300 nm?and SG?200 nm?,the arrangement of molecular are similar to normal condition in some degree.in the small-bore of CPG?12nm?and SG?15 nm?,the alkanol molecules are obviously showed new structure because of the sort order disorganized.May be largely due to size effect and surface effect of porous materials.?4?What is to explore in our experimental study is the phase change behavior in even carbon 1-hexadecanol?C16OH?and 1-octadecanol(C₁₈OH)under the different porous materials.The phase transition peak is separated In the hole,The decrease rate of Solid-liquid phase change temperature is slower than solid-solid phase change temperature,Phase transition temperature in each material are reduced due to differences in the characteristics of the wall of hole and the polarity of the hole,Due to channel structure and the size effect in small diameter hole material will appear new rotation phase.