Heterogeneity of the state and functionality of water molecules sorbed in an amorphous sugar matrix

由糖分子组成的无定形材料具有很高的吸湿性，吸附的水对基质的物理稳定性有很大影响。到目前为止，无定形糖的吸水行为已被广泛研究。然而，大多数关于水的行为的研究，当被吸附到无定形的糖基质时，都隐含地假设所有被吸附的水分子都处于单一的状态：自然地，糖分子的随机分配和配置将导致被吸附的水的状态的异质性。最近，我们结合傅里叶变换红外光谱和傅里叶自反卷积技术，证明了水在无定形糖基质中吸附的状态和官能度的异质性；将吸附的水分子分为五种状态，其中三种状态主要用于降低无定形糖基质的玻璃化转变温度，而另外两种状态是独立的。

Amorphous materials, comprised of sugar molecules, exhibit high hygroscopicity and the sorbed water exerts a major influence on physical stabilities of the matrix. To date, the water sorption behavior of amorphous sugars has been extensively investigated. However, most studies of the behavior of water, when sorbed to an amorphous sugar matrix, have implicitly assumed that all of the sorbed water molecules are in a single state: It is naturally expected that the random allocation and configuration of sugar molecules would result in heterogeneity of states for the sorbed water. Recently, we demonstrated the heterogeneity of state and functionality of water sorbed in amorphous sugar matrices by combining a Fourier transform IR spectroscopy and Fourier self-deconvolution technique; The sorbed water molecules were classified into five states, and the three of them mainly served to lower the glass transition temperature of an amorphous sugar matrix while the other two are independent.