Carbon Dioxide‐Switchable Chitosan/Polymer Composite Nanogels

Abstract

Carbon dioxide (CO2)‐switchable composite nanogels are composed of biopolymer chitosan (CS) and synthetic polymer poly [N‐(3‐(dimethylamino) propyl) methacrylamide] (PDMAPMA). CS/PDMAPMA composite nanogels (CPCNGs) are fabricated in the solution of chitosan by soap‐free emulsion polymerization using N‐(3‐[dimethylamino] propyl) methacrylamide (DMAPMA) as the monomer and N,N‐methylenebis (acrylamide) (BIS) as the cross‐linker. The scanning electron microscope (SEM) results indicate that the nanogels are spherical nanoparticles with a diameter of about 50 nm. After purging with CO2, the original creamy‐white latex becomes a clear solution. While purging with N2, the clear solution is returned to the original latex state. Introduction of chitosan in nanogels remarkably enhances their CO2 sensitivity. In additional, the SEM results also suggest that phase transition behavior occurs through CO2 and N2 bubbling. The initial state of nanogels can be easily recovered by “washing off” the trigger gas with N2.

Advances in metal–organic framework-based hydrogel materials: preparation, properties and applications

“…287,288 The free amino groups in chitosan were able to provide basic sites for CO 2 , and thus chitosan was considered as a potential CO 2 -responsive polymer. 289,290 As a classic report, Wang et al successfully synthesized ZIF-8/chitosan nanocomposites using a chitosan hydrogel as the research object. 291 The chitosan concentrations and the ammonium hydroxide solution varied in the preparation of ZIF-8/chitosan nanocomposites.…”

Chitosan/ZIF‐8 Composite Beads Fabricated by In Situ Growth of MOFs Crystals on Chitosan Beads for CO2 Adsorption

“…[32] The presence of free amino groups in the structure of CS could provide basic sites for CO 2 . [33][34][35] Hence, introducing of CO 2 responsive polymers could enhance the absorption capacity and selectivity of ZIF-8 for CO 2 . Moreover, MOFs combining to flexible polymers would greatly improve the flexibility, recyclability and processability of MOFs.…”

“…Additionally, CS contained a large number of functional groups, which allowed it to load metal ions by coordination [32] . The presence of free amino groups in the structure of CS could provide basic sites for CO 2 [33–35] . Hence, introducing of CO 2 responsive polymers could enhance the absorption capacity and selectivity of ZIF‐8 for CO 2 .…”

pH-Switchable Latexes Based on the Nonionic Amphiphilic Diblock Copolymer with a Chargeable End-Group on the Core-Forming Block

“…Stimulus-responsive polymers have motivated extensive academic interests and numerous potential applications including catalysis, smart gels, , detectors, , water treatment, and drug encapsulation or delivery. − Among various polymers with different architectures, block copolymers (BCPs) are the most extensively studied systems due to their unique self-assembly in bulk or solution. , In aqueous solution, the final morphology of amphiphilic AB diblock copolymer aggregates generally depends on the hydrophobic/hydrophilic balance of two blocks. This is sensitive to changes in polymer chain solubility or conformation, which can be adjusted with many stimuli, such as temperature, pH, CO 2 , redox, light, and host–guest or dynamic covalent interactions. − Through a traditional postpolymerization process approach or the efficient polymerization-induced self-assembly (PISA) technique based on controlled/“living” polymerizations, stimulus-responsive amphiphilic BCPs have been used to construct a wide range of smart nanostructures (spheres, worms, vesicles, nanotubes, etc.…”