Surface characterization of untreated and solvent-extracted rice straw.

Surface characteristics of untreated and solvent extracted rice straw and intact rice plant stem and sheath tissue have been investigated using reflectance Fourier transform infrared spectroscopy (FTIR-ATR), electrokinetic analysis (EKA), and scanning electron microscopy (SEM). Klason lignin and Kappa numbers were determined according to TAPPI standard methods. Sohxlet extractions were performed with hexanes, ethyl acetate, chloroform, ethanol-toluene and benzene-ethanol azeotropes.