Thermally stable cellulose nanospheres prepared from office waste paper by complete removal of hydrolyzed sulfate groups

Duc-Ninh Lam; Doan Van Hong Thien; Chanh-Nghiem Nguyen; Nhung Tuyet Thi Nguyen; Nguyen Van Viet; Dan-Thuy Van-Pham

doi:10.1016/j.carbpol.2022.120009

Thermally stable cellulose nanospheres prepared from office waste paper by complete removal of hydrolyzed sulfate groups

Carbohydr Polym. 2022 Dec 1:297:120009. doi: 10.1016/j.carbpol.2022.120009. Epub 2022 Aug 18.

Authors

Duc-Ninh Lam¹, Doan Van Hong Thien¹, Chanh-Nghiem Nguyen², Nhung Tuyet Thi Nguyen³, Nguyen Van Viet¹, Dan-Thuy Van-Pham⁴

Affiliations

¹ Department of Chemical Engineering, College of Engineering Technology, Can Tho University, Campus II, 3/2 Street, Xuan Khanh, Ninh Kieu, Can Tho, Viet Nam.
² Department of Automation Technology, College of Engineering Technology, Can Tho University, Campus II, 3/2 Street, Xuan Khanh, Ninh Kieu, Can Tho, Viet Nam.
³ Department of Chemistry, School of Education, Can Tho University, Campus II, 3/2 Street, Xuan Khanh, Ninh Kieu, Can Tho, Viet Nam.
⁴ Department of Chemical Engineering, College of Engineering Technology, Can Tho University, Campus II, 3/2 Street, Xuan Khanh, Ninh Kieu, Can Tho, Viet Nam. Electronic address: vpdthuy@ctu.edu.vn.

PMID: 36184136
DOI: 10.1016/j.carbpol.2022.120009

Abstract

Cellulose nanocrystals are commonly obtained by acid hydrolysis, particularly with H₂SO₄. However, a small amount of deposited sulfate-groups contributes to the degradation of their thermal stability. This study prepared thermally-stable and sulfate-group-free cellulose nanospheres (CNSs) from office waste paper by H₂SO₄ hydrolysis followed by solvolytic desulfation. The optimal desulfation conditions (i.e., 5 wt% MeOH, reaction temperature of 90 °C, a reaction time of 20 min, 0.5 mM pyridine) were preliminarily found from a one-factor-at-a-time experiment and validated by the results of a central composite design. The optimal desulfation conditions promoted environmental sustainability with less pyridine and MeOH and comparably shorter reaction time. The desulfated CNSs had a significant thermal stability enhancement from 186 to 340 °C. Comprehensive characterization of the morphology, chemical composition, and thermal behavior of the desulfated CNSs reconfirmed the complete removal of sulfate groups without harmful pyridine residues, demonstrating the potential use of the thermally stable CNSs.

Keywords: Acidic hydrolysis; Cellulose nanospheres; Desulfation; Pyridine residues; Solvolytic method; Thermal stability.

MeSH terms

Cellulose* / chemistry
Hydrolysis
Nanospheres*
Pyridines
Sulfates / chemistry
Sulfur Oxides

Substances

Pyridines
Sulfates
Sulfur Oxides
Cellulose