Simultaneous Determination of the Micro-, Meso-, and Macropore Size Fractions of Porous Polymers by a Combined Use of Fourier Transform Near-Infrared Diffuse Reflection Spectroscopy and Multivariate Techniques
作者:N. Heigl、A. Greiderer、C. H. Petter、O. Kolomiets、H. W. Siesler、M. Ulbricht、G. K. Bonn、C. W. Huck
DOI:10.1021/ac8013059
日期:2008.11.15
Fourier transform near-infrared (FT-NIR) diffuse reflection spectroscopy was used in combination with principal component analysis and partial least-squares regression to simultaneously determine the physical and the chemical parameters of a porous poly(p-methylstyrene-co-1,2-bis(p-vinylphenyl)ethane) (MS/BVPE) monolithic polymer. Chemical variations during the synthesis of the polymer material can alter the pore volume and pore area distributions within the polymer scaffold. Furthermore, mid-infrared and near-infrared (NIR) spectroscopic chemical imaging was implemented as a tool to assess the uniformity of the samples. The presented study summarizes the comparative results derived from the spectral FT-NIR data combined with chemometric techniques. The relevance of the interrelation of physical and chemical parameters is highlighted whereas the amount of MS/BVPE (%, v/v) and the quantity (%) of micropores (diameter, d < 6 nm), mesopores (6 nm < d < 50 nm), and macropores (50 nm < d < 200 nm) could be determined with one measurement. For comparison of the quantitative data, the standard error of prediction (SEP) was used. The SEP for determining the MS/BVPE amount in the samples showed 0.35%, for pore volume quantiles 1.42−8.44%, and for pore area quantiles 0.38−1.45%, respectively. The implication of these results is that FT-NIR spectroscopy is a suitable technique for the screening of samples with varying physicochemical properties and to quantitatively determine the parameters simultaneously within a few seconds.
傅里叶变换近红外(FT-NIR)漫反射光谱与主成分分析和偏最小二乘回归相结合,可同时测定多孔聚(对甲基苯乙烯-共-1,2-双(对乙烯基苯基)乙烷)(MS/BVPE)整体聚合物的物理和化学参数。聚合物材料合成过程中的化学变化会改变聚合物支架内的孔体积和孔面积分布。此外,中红外和近红外(NIR)光谱化学成像被用作评估样品均匀性的工具。本研究总结了从光谱FT-NIR数据结合化学计量学技术得出的比较结果。物理和化学参数之间的相互关系得到了强调,而MS/BVPE(%,v/v)的量和微孔(直径,d < 6 nm)、中孔(6 nm < d < 50 nm)和大孔(50 nm < d < 200 nm)的数量(%)可以通过一次测量确定。为了比较定量数据,使用了预测标准误差(SEP)。用于确定样品中MS/BVPE量的SEP分别为0.35%,孔体积分位数为1.42-8.44%,孔面积分位数为0.38-1.45%。这些结果表明,FT-NIR光谱是一种适合筛选具有不同物理化学特性的样品的技术,并且可以在几秒钟内同时定量确定参数。