%0 Journal Article %1 WOS:000460617900022 %A Vasconcelos, Niedja Fittipaldi %A Feitosa, Judith Pessoa Andrade %A Andrade, Fabia Karine %A Miranda, Marcus Aurelio Ribeiro %A Sasaki, Jose Marcos %A Morais, Joao Paulo Saraiva %A e Silva, Lorena Mara Alexandre %A Canuto, Kirley Marques %A de Rosa, Morsyleide Freitas %C VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS %D 2019 %I SPRINGER %J CELLULOSE %K Carboxymethylation; Chitosan; Hydrolysis; Nanocrystals; Polyelectrolytic cellulose; complexes} {Bacterial %N 3 %P 1725-1746 %R 10.1007/s10570-018-2223-3 %T Chemically modified cellulose nanocrystals as polyanion for preparation of polyelectrolyte complex %V 26 %X Bacterial cellulose nanocrystals (BCNCs) have hydrophilic surfaces due to hydroxyl groups but are water-insoluble. The carboxymethylation improves the solubility of cellulose in polar media through the insertion of carboxymethyl groups. This study aims to evaluate the use of two different alcoholic solvents in the carboxymethylation reaction of BCNCs: ethanol and isopropanol. BCNCs were obtained under two hydrolysis conditions: sulfuric acid (BCNC-S) and combination of sulfuric and hydrochloric acids (BCNC-S/Cl). Two techniques (NMR and titration) were used to determine the degree of substitution (DS) values. Carboxymethylation of BCNC-S/Cl led to high DS compared to BCNC-S and the use of isopropanol promoted an even greater DS. The thermal properties were not affected after the chemical modification. However, functionalization provided an increase in the negative charge density at the surface of nanostructures and a change in the crystal structure (cellulose type I for amorphous), making this material a potential polyanion for the synthesis of polyelectrolyte complexes (PECs). The micrographs showed that the nanocrystals became soluble after carboxymethylation. Carboxymethylated bacterial cellulose nanocrystals hydrolyzed through the mixture of inorganic acids and modified using isopropanol (CBCNC-S/Cl-IPA) was a suitable polyanion to produce PECs with chitosan. The PECs produced had particle size ranging from 276 to 588nm and zeta potential ranging from -24.3 to +39.0mV. GRAPHICS .

@article{WOS:000460617900022, abstract = {Bacterial cellulose nanocrystals (BCNCs) have hydrophilic surfaces due to hydroxyl groups but are water-insoluble. The carboxymethylation improves the solubility of cellulose in polar media through the insertion of carboxymethyl groups. This study aims to evaluate the use of two different alcoholic solvents in the carboxymethylation reaction of BCNCs: ethanol and isopropanol. BCNCs were obtained under two hydrolysis conditions: sulfuric acid (BCNC-S) and combination of sulfuric and hydrochloric acids (BCNC-S/Cl). Two techniques (NMR and titration) were used to determine the degree of substitution (DS) values. Carboxymethylation of BCNC-S/Cl led to high DS compared to BCNC-S and the use of isopropanol promoted an even greater DS. The thermal properties were not affected after the chemical modification. However, functionalization provided an increase in the negative charge density at the surface of nanostructures and a change in the crystal structure (cellulose type I for amorphous), making this material a potential polyanion for the synthesis of polyelectrolyte complexes (PECs). The micrographs showed that the nanocrystals became soluble after carboxymethylation. Carboxymethylated bacterial cellulose nanocrystals hydrolyzed through the mixture of inorganic acids and modified using isopropanol (CBCNC-S/Cl-IPA) was a suitable polyanion to produce PECs with chitosan. The PECs produced had particle size ranging from 276 to 588nm and zeta potential ranging from -24.3 to +39.0mV. [GRAPHICS] .}, added-at = {2022-05-23T20:00:14.000+0200}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, author = {Vasconcelos, Niedja Fittipaldi and Feitosa, Judith Pessoa Andrade and Andrade, Fabia Karine and Miranda, Marcus Aurelio Ribeiro and Sasaki, Jose Marcos and Morais, Joao Paulo Saraiva and e Silva, Lorena Mara Alexandre and Canuto, Kirley Marques and de Rosa, Morsyleide Freitas}, biburl = {https://www.bibsonomy.org/bibtex/220cf5bb151bd07e1ec9c02464083f830/ppgfis_ufc_br}, doi = {10.1007/s10570-018-2223-3}, interhash = {bc567ddaf375bd3de2c158377f38118a}, intrahash = {20cf5bb151bd07e1ec9c02464083f830}, issn = {0969-0239}, journal = {CELLULOSE}, keywords = {Carboxymethylation; Chitosan; Hydrolysis; Nanocrystals; Polyelectrolytic cellulose; complexes} {Bacterial}, number = 3, pages = {1725-1746}, publisher = {SPRINGER}, pubstate = {published}, timestamp = {2022-05-23T20:00:14.000+0200}, title = {Chemically modified cellulose nanocrystals as polyanion for preparation of polyelectrolyte complex}, tppubtype = {article}, volume = 26, year = 2019 }