Controlled Polyelectrolyte Association of Chitosan and Carboxylated Nano-Fibrillated Cellulose by Desalting

Abstract

We prepared chitosan (CHI) hydrogels reinforced with highly charged cellulose nanofibrils (CNF) by the desalting method. To this end, the screening of electrostatic interactions between CHI polycation and CNF polyanion was performed by adding NaCl at 0.4 mol/L to the chitosan acetate solution and to the cellulose nanofibrils suspension. The polyelectrolyte complexation between CHI polycation and CNF polyanion was then triggered by desalting the CHI/CNF aqueous mixture by multistep dialysis, in large excess of chitosan. Further gelation of non-complexed CHI was performed by alkaline neutralization of the polymer, yielding high reinforcement effects as probed by the viscoelastic properties of the final hydrogel. The results showed that polyelectrolyte association by desalting can be achieved with a polyanionic nanoparticle partner. Beyond obtaining hydrogel with improved mechanical performance, these composite hydrogels may serve as precursor for dried solid forms with high mechanical properties.

Synthesis of High Performance Thiophene–Aromatic Polyesters from Bio-Sourced Organic Acids and Polysaccharide-Derived Diol: Characterization and Degradability Studies

“…The substitution of fossil-based resources with molecules extracted from the biomass represents one of the most important targets of green chemistry [ 13 , 14 , 15 , 16 , 17 ]. This replacement is associated with two main goals: the use of renewable sources instead of fossil ones, and the development of a low-carbon economy geared towards reducing waste and minimizing resources consumption [ 18 , 19 , 20 , 21 , 22 , 23 ]. Nevertheless, contemporary requirements necessitate further research to introduce additional chemical functionalities exhibiting a higher reactivity as compared with currently available, petroleum-based sources [ 24 , 25 , 26 , 27 , 28 ].…”

Hydroxyapatite/L-Lysine Composite Coating as Glassy Carbon Electrode Modifier for the Analysis and Detection of Nile Blue A

“…This can be explained by the electrostatic attraction forces existing between the carboxylate groups of the amino acids and the Ca 2+ cations on the surface of HA. Such interactions have also been highlighted in various published works [47,[54][55][56][57][58]. Besides, the intermolecular H bonds existing between the N-containing group and the phosphate on the HA surface, as well as the cooperation of several protein functions, Ca 2+ cations, and phosphate groups on the surface of HA, could explain this affinity.…”

Fabrication of an Organofunctionalized Talc-like Magnesium Phyllosilicate for the Electrochemical Sensing of Lead Ions in Water Samples

“…The high peak currents (anodic and cathodic) and a strong accumulation up to the 20th scan could be due to the electrostatic attraction between the negatively charged redox system [Fe(CN) 6 ] 3− and the positively charged amino (-NH 3 + ) groups present on the organosilane fragments used in the synthesis process. Several recently published works have highlighted the good affinity that protonated amine functions have in an acid medium to interact (through electrostatic interactions) with either negatively charged molecules or those having free pairs of electrons capable of reacting with other species in solution [ 64 , 65 , 66 ].…”