The states of water in tryptophan grafted hydroxypropyl methylcellulose hydrogels and their effect on the adsorption of methylene blue and rhodamine B

Author(s)

Toledo, Paulo V. O. ; Bernardinelli, Oigres D. ; Sabadini, Edvaldo ; Petri, Denise F. S.

• Document type: Journal article
• Source: Carbohydrate Polymers; v. 248, p. 10-pg., 2020-11-15.

Abstract

Tryptophan (Trp) decorated hydroxypropyl methylcellulose (HPMC) cryogels were prepared by a one-step reaction with citric acid. The increase of Trp content in the 3D network from 0 to 2.18 wt% increased the apparent density from 0.0267 g.cm(-3) to 0.0381 g.cm(-3) and the compression modulus from 94 kPa to 201 kPa, due to hydrophobic interactions between Trp molecules. The increase of Trp content in HPMC-Trp hydrogels increased the amount of non-freezing water, estimated from differential scanning calorimetry, and the amount of freezing water, which was determined by time-domain nuclear magnetic resonance. The adsorption capacity of methylene blue (MB) and rhodamine B (RB) on HPMC-Trp hydrogels increased with Trp content and the amount of freezing water. HPMC-Trp hydrogels could be recycled 6 times keeping the original adsorptive capacity. The diffusional constants of MB and RB tended to increase with Trp content. RB adsorbed on HPMC-Trp hydrogels presented a bathochromic shift of fluorescence. (AU)

• FAPESP's process: 18/13492-2 - Synthetic and natural scaffolds applied to regenerative medicine
• Grantee: Luiz Henrique Catalani
• Support Opportunities: Research Projects - Thematic Grants