Control and Preparation of Quaternized Chitosan and Carboxymethyl Chitosan Nanoscale Polyelectrolyte Complexes Based on Reactive Flash Nanoprecipitation

Abstract

Nanoscale polyelectrolyte complex materials have been extensively investigated for their promising application in protocell, drug carriers, imaging, and catalysis. However, the conventional preparation approach involving positive and negative polyelectrolytes leads to large size, wide size distribution, instability, and aggregation due to the nonhomogeneous mixing process. Herein, we employ reactive flash nanoprecipitation (RFNP) to control the mixing and preparation of the nanoscale polyelectrolyte complex. With RFNP, homogeneous mixing complexation between oppositely charged chitosan derivatives could be achieved, resulting in stable nanoscale complexes (NCs) with controllable size and narrow size distribution. The smallest size of NCs is found at specific pH due to the maximum attraction of positive and negative molecules of chitosan. The size can be modulated by altering the volumetric flow rates of inlet streams, concentration, and charge molar ratio of two oppositely charged chitosan derivatives. The charge molar ratio is also tuned to create NCs with positive and negative shells. There is no significant variation in the size of NCs produced at different intervals of time. This method allows continuous and tunable NC production and could have the potential for fast, practical translation.

Aqueous nanoprecipitation for programmable fabrication of versatile biopolymer nanoparticles

“…2,10 In recent studies, biopolymer nanoparticles have also shown attractive capabilities in catalysis, 11 sensing 12 and environmental remediation. 13 The common approaches for fabricating biopolymer nanoparticles are as follows: (1) self-assembly of synthetic amphiphilic biopolymer derivatives; 14,15 (2) complexation of polyelectrolyte biopolymers with oppositely charged reagents; [16][17][18] (3) emulsification-based techniques; [19][20][21] and (4) nanoprecipitation. 22,23 In stark contrast to common time/energy-intensive methods, nanoprecipitation (also called the "Ouzo effect" or "solvent-shifting process") has shown appealing features of a straightforward, scalable and low-energy-cost production process, allowing for on-demand preparation of polymer colloids with narrow size distribution without using surfactants.…”

“…2,10 In recent studies, biopolymer nanoparticles have also shown attractive capabilities in catalysis, 11 sensing 12 and environmental remediation. 13 The common approaches for fabricating biopolymer nanoparticles are as follows: (1) self-assembly of synthetic amphiphilic biopolymer derivatives; 14,15 (2) complexation of polyelectrolyte biopolymers with oppositely charged reagents; 16–18 (3) emulsification-based techniques; 19–21 and (4) nanoprecipitation. 22,23…”