Characterization of corn husks carboxymethyl cellulose formation using Raman spectroscopy

The economic value of corn husk agricultural waste can be enhanced by converting it into cellulose and carboxymethyl cellulose (CMC) instead of incineration, which reducing PM 2.5 (particulate matter with diameter less than 2.5 µm) as air pollution. Corn husks were processed into cellulose and CMC, with carboxymethylation performed using varying NaOH concentrations (20–60 g/100 mL) and constant monochloroacetic acid in isopropanol for degree of substitution (DS). The highest CMC yield (189.47 %) from DS with 1.53 was achieved at 30 g/100 mL NaOH. The DS of carbonyl functional groups significantly enhanced CMC properties compared to original cellulose. Raman scattering spectra confirmed CMC quality, showing combined cellulose I ( I 380 /I 1096 ) and cellulose II ( I 577 /I 1096 ) structures. CMC with low DS (0.36) retained more cellulose I ( I 380 /I 1096 : 0.93), while higher DS (1.53) transformed it into cellulose II ( I 380 /I 1096 : 0.29). The existence of I 577 /I 1096 : 0.19–0.37 increased with DS, indicating the crystallinity formation of cellulose II. These findings suggest that increasing DS enhanced cellulose II contents, analyzed using Raman scattering analysis and this approach simultaneously enhanced the CMC yield from 111.77 % to 189.47 %. This biodegradable CMC production from corn husks offers a sustainable alternative to reducing PM 2.5 air pollution and obtains high-quality CMC materials through agricultural waste management. • CMC structure was produced from corn husks and characterized using Raman spectroscopy. • CMC contained cellulose I and mainly cellulose II, obtained by the substitution with NaOH. • Cellulose I & cellulose II were characterized via the Raman scattering of CMC. • CMC yield increased from 111.17 % to 189.47 %, confirming via the enhanced Raman spectra of cellulose II.