In order to examine the mixing properties of glycerol–water and diglycerol–water solutions, these solutions were measured using attenuated total reflection infrared spectroscopy. The absorbance spectra corrected for 1 µm thickness were subtracted by pure polyols for obtaining water spectra, and by pure water for polyol spectra. Both asymmetric and symmetric CH2 stretching vibration bands (around 2940, 2885 cm−1) shifted about 10 cm−1 to lower wavenumber side (redshifts) with increasing polyol concentrations, especially at higher concentrations. Redshifts of C–O–H rocking bands (around 1335 cm−1) with increasing polyol concentrations are slightly larger for diglycerol–water (10 > 6 cm−1) than glycerol–water solutions. C–O stretching bands of CHOH groups (1125 and 1112 cm−1) shift slightly but in opposite sides for glycerol and diglycerol at highest polyol concentrations (90–100 wt%). These shifts of CH2 stretching, COH rocking, and CO stretching of CHOH at higher polyol concentrations suggest interactions of outer CH2 with inner CHOH groups of surrounding polyols. The normalized band area changes with polyol concentrations could be fitted by quadratic polynomials possibly due to mixtures of different interactions between water–water, polyol–water, and polyol–polyol molecules. The OH stretching band for diglycerol 90 wt% shows three humps indicating at least three OH components: long, medium, and short H bond water molecules. Short H bond water molecules are the major component possibly between inner CHOH and outer side CH2OH groups, while the long H component might loosely bind to outer CH2OH groups.

中文翻译：

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EXPRESS：使用衰减全反射红外光谱研究甘油、双甘油和水的相互作用

为了检查甘油-水和双甘油-水溶液的混合特性，使用衰减全反射红外光谱测量这些溶液。对 1 µm 厚度校正的吸收光谱减去纯多元醇以获得水光谱，并减去纯水以获得多元醇光谱。随着多元醇浓度的增加，尤其是在较高浓度下，不对称和对称 CH2 伸缩振动带（约 2940、2885 cm-1）都向低波数侧（红移）移动了约 10 cm-1。随着多元醇浓度的增加，C-O-H 摇摆带（约 1335 cm-1）的红移对于双甘油-水（10 > 6 cm-1）比甘油-水溶液略大。CHOH 基团的 C-O 伸缩带（1125 和 1112 cm-1）略微移动，但在最高多元醇浓度（90-100 wt%）下，甘油和双甘油在相反侧移动。CH2 拉伸、COH 摇摆和 CHOH 在较高多元醇浓度下的 CO 拉伸的这些变化表明，外部 CH2 与周围多元醇的内部 CHOH 基团相互作用。归一化带面积随多元醇浓度的变化可以通过二次多项式拟合，这可能是由于水 - 水、多元醇 - 水和多元醇 - 多元醇分子之间不同相互作用的混合物。双甘油 90 wt% 的 OH 伸缩带显示三个驼峰，表明至少三个 OH 组分：长、中和短 H 键水分子。短 H 键水分子可能是内部 CHOH 和外部 CH2OH 基团之间的主要成分，