Figure 5
The Fourier transform Raman spectra of filter paper and cotton linter celluloses after pretreatments with dilute acid and/or ferrous ions. (A) Acid-alone (control) pretreated filter paper (FP) showing major peaks. (B) FP with various pretreatments. (C) Cotton linter (CL) with various pretreatments. (D) Non-pre-treated FP and CL. Asterisk in part (B) highlights the major peaks affected by the dilute acid/Fe2+ ion pretreatment.