Controlled coagulation and redispersion of thermoresponsive poly di(ethylene oxide) methyl ether methacrylate grafted cellulose nanocrystals

Autor(es)

Brinatti, Cesar ^[1] ; Akhlaghi, Seyedeh Parinaz ^[1] ; Pires-Oliveira, Rafael ^[1] ; Bernardinelli, Oigres Daniel ^[1] ; Berry, Richard M. ^[2] ; Tam, Kam Chiu ^[3] ; Loh, Watson ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, UNICAMP, Inst Chem, CP 6154, BR-13083970 Campinas, SP - Brazil

^[2] CelluForce Inc, 625 President Kennedy Ave, Montreal, PQ H3A 1K2 - Canada

^[3] Univ Waterloo, Waterloo Inst Nanotechnol, Dept Chem Engn, 200 Univ Ave West, Waterloo, ON N2L 3G1 - Canada

• Tipo de documento: Artigo Científico
• Fonte: Journal of Colloid and Interface Science; v. 538, p. 51-61, MAR 7 2019.
• Citações Web of Science: 3

Resumo

Hypothesis: Cellulose nanocrystals (CNCs) undergo precipitation in the presence of high concentrations of cationic surfactants in aqueous solutions. To avoid such behavior and/or to promote redispersion of CNC/surfactant mixtures, the CNC surface was grafted with poly di(ethylene oxide) methyl ether methacrylate, P(MEO(2)MA). Experiments: CNC-g-P(MEO(2)MA) was characterized using the following techniques C-13 solid-state nuclear magnetic resonance (C-13 SSNMR), Fourier-transform infrared spectroscopy - attenuated total reflection spectroscopy (FTIR-ATR) and thermal gravimetric analysis (TGA). Isothermal titration calorimetry (ITC), electrophoretic mobility, light scattering and high sensitivity differential scanning calorimetry (HSDSC) were used to study the interaction between CNC-g-P(MEO(2)MA) and ionic surfactants, dodecyltrimethylammonium bromide (C(12)TAB, cationic) and sodium dodecylsulfate (SDS, anionic) at temperatures below and above the LCST. Findings: CNC-g-P(MEO(2)MA) underwent phase separation above its lower critical solution temperature (LCST similar to 25 degrees C) and precipitated from solution as seen by HSDSC and transmittance experiments. When C(12)TAB was added to CNC-g-P(MEO(2)MA) it induced the precipitation that prevented the redispersion due to strong electrostatic interactions with the negative charges on the CNC surface. With increasing concentrations of SDS, the polymer phase transition temperature was increased, which can be used to redisperse the CNC complexes. By removing SDS from the mixture via dialysis, the CNC-g-P(MEO(2)MA) underwent subsequent phase transition. (C) 2018 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 14/24305-8 - Máscaras de Celulose Bacteriana Carregadas com Cubossomas contendo o Peptídeo Pal-KTTKS: Um Sistema Multifuncional de Cuidados com a Pele
• Beneficiário: Seyedeh Parinaz Akhlaghi
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado