Carboxymethyl Cellulose/Poly (Acrylamide-co-vinyl imidazole) Based Self-Healing Hydrogel for Supercapacitor Applications and Moisture Determination: Synthesis, Characterisation, and Functional Evaluation (Part-II) | Chapter 8 | Chemistry and Biochemistry: Research Progress Vol. 9

 

Hydrogels’ self-healing process involves reconstructing the damaged network structure, which is typically mediated by the reversible interactions among the polymer chains. A number of approaches have been employed to fabricate self-healing hydrogels. These include hydrogen bonding, host-guest recognition, electrostatic interactions, hydrophobic associations, metal-ligand coordination, dynamic covalent bonds, etc. This chapter describes the physical entanglements between carboxymethyl cellulose (CMC) chains and poly (acrylamide-co-vinyl imidazole)(poly(AAm-co-VI), which resulted in a unique solid hydrogel electrolyte(SHE) material with highly controllable properties. The SHE was synthesised by carrying out free radical co-polymerisation of monomer Acrylamide and vinyl imidazole in the presence of dissolved CMC at 40 °C. The SHE was characterised using rheological, mechanical, adhesion, and electrochemical techniques. The SHE showed an excellent self-healing property, as confirmed by the “LED glowing” experiment, and the ‘self-healed ‘material recovered 78% of its original elongation capacity. The freshly prepared SHE, when put on a copper surface, required a Detachment Pressure (DP) of 864 Pa, while a fairly high DP of 8909 Pa was required after 24 h of contact. The SHE sample was highly flexible and regained its shape after knotting, folding and twisting. The hydrogel also exhibited shape memory property. Finally, the samples SHE-I and SHE-IV (containing 0 and 4 ml glycerol per 40 ml of film-forming solution) were charged using a 12-volt battery for 2 min and then employed to glow an LED bulb as well as run an alarm clock. It was found that the sample SHE-I was able to glow the LED bulb for almost 55 min, while the sample SHE-IV successfully lit the LED for almost 357 min. Similarly, a small alarm clock was run by the two SHE systems for 118 and 838 min respectively. The hydrogel sample SHE-IV, loaded with glycerol and the sample SHE-V, loaded with the salt ZnCl2 demonstrated excellent anti-freezing behavior by maintaining the electrical connectivity in the circuit even at -25oC. Finally, the sample SHE-I was prepared with a highly porous texture and used as a “Gravimetric Analyzer for Humidity Monitoring” (GAHM). The moisture absorption-desorption capacity of GAHM was tested by putting it before a hot air blower for 600 s, followed by its immediate transfer in RH atmosphere of 75%. It attained the Equilibrium mass within a short period of 600 s. Owing to hydrogen-bonding interactions and mutual polymer-chain entanglements, the SHE possesses self-healing, shape memory, adhesiveness, and flexibility. It also functions as a rechargeable supercapacitor, which lasts longer in the presence of glycerol.

 

 

Author(s) Details

Deepika Dubey
Polymer Research Laboratory, Department of Chemistry, Govt. Model Science College, Jabalpur (M.P.)-482001, India.

 

S. K. Bajpai
Polymer Research Laboratory, Department of Chemistry, Govt. Model Science College, Jabalpur (M.P.)-482001, India.

 

Manjula Bajpai
Polymer Research Laboratory, Department of Chemistry, Govt. Model Science College, Jabalpur (M.P.)-482001, India.

 

Please see the book here :- https://doi.org/10.9734/bpi/cbrp/v9/7031