FTIR technique was used to obtain the specific functional groupsor chemical bonds in BC samples. The FTIR spectra of the BC mem-branes were measured with the wave number of 4000–400 cm−1asis shown in Fig. 5. The various BC samples showed several impor-tant peaks of BC at 1054 (stretching of C O), 1646 (stretching ofC O), 2896 (stretching of CH) and 3343 (stretching of C O) (Brown,1886; Lin et al., 2014). The results confirmed that three BC exhibitedsimilar chemical binding.