摘要
采用液相浸渍法研究了蔗糖在中孔MCM-48表面的自发单层分散.用X射线衍射(XRD)相定量分析法,测定了蔗糖在MCM-48上的最大分散容量,并用差热分析、N_2吸附技术对制备的样品进行表征.结果表明,在蔗糖与MCM-48的质量比小于1.1时,蔗糖在MCM-48表面能自发分散成单层.当蔗N/MCM-48质量比为0.8时,MCM-48的比表面积由初始的998 m^2·g^(-1)降至114 m^2·g^(-1),孔径由原来的2.7 nm降至2.0 nm,孔容由0.76 cm^3·g^(-1)降至0.11 cm^3·g^(-1).当蔗糖与MCM-48的质量比超过1.1时,MCM-48的比表面积迅速减小至10 m^2·g^(-1)以下.这是因为蔗糖分子大小和MCM-48孔径相差不大,导致蔗糖在MCM-48表面分散时出现孔道堵塞.
The spontaneous monolayer dispersion of sucrose on the surface of MCM-48 by impregnation method was studied,and its monolayer dispersion capacity was determined by XRD quantitative phase analysis.The sucrose/ MCM-48 samples were characterized by DTA and N_2 adsorption.It was found that sucrose could readily monolayerly dispersed on MCM-48,with a monolayer dispersion capacity of 1.1g sucrose/g MCM-48.When 0.8g sucrose per g MCM-48 was dispersed on MCM-48,the specific surface area of MCM-48 was decreased from 998 m^2·g^-1 to 114m^2·g^-1,with the decrease of the mean pore size from 2.7 nm to 2.0 nm.Further increase of sucrose amount more than the monolayer dispersion capacity resulted in the decrease of the specific surface area to less than 10 m^2·g^-1.This might be related to the limited difference between the pore size of MCM-48 and the molecular diameter of sucrose,which led to the blockage of the pores of MCM-48 at high sucrose amount.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2007年第9期1463-1467,共5页
Acta Physico-Chimica Sinica
基金
江苏省"青蓝工程"资助项目
关键词
蔗糖
自发单层分散
MCM-48
分散阈值
Sucrose
Spontaneous monolayer dispersion
MCM-48
Monolayer dispersion capacity
