In order to analyze the changes of the function groups of the biomass in the chemicalmodification process, the OTAB and CMTAB were characterized with FTIR. According to the analysis of IR spectra (Fig. 1), the band positions for the function groups are listed in Table 2. Both of the spectra indicate that hydroxyl and amino peaks are at wavenumber ∼3440 cm−1; alkyl CH2 peaks at wavenumber ∼2926 to 2929 cm−1 and 2850 to 2853 cm−1; the C O bond of carboxyl groups and their esters or amides peaks at wavenumber ∼1732 to 1627 cm−1. The peaks at wavenumber ∼1300 to 1000 cm−1 are attributed to the C N stretching and/or C O stretching, and the peaks at wavenumber lower than 1000 cm−1 is deemed to the finger print of some inorganic functional groups (e.g., phosphate and sulphur groups) [30]