Table 1.

The composition and properties of irreversible electrically conductive hydrogels that are based on natural polymers substrates that are filled with conductive polymers.

Gelation Mechanism	Polymeric Substrates	Electric Conductive Mediums	Conductivity	Mechanical Performance	References
Graft-polymerization via acrylic acid	Carboxymethyl cellulose	PANI	0.75 S/cm	N/A	[69]
Graft-polymerization via acrylamide	Carboxymethyl cellulose	PANI	2.71 × 10−4 S/cm	N/A	[126]
Chemical cross-linking via glycerol diglycidyl ether	Carboxymethyl cellulose	PANI	6.31 × 10−3 S/cm	N/A	[127]
Hydrogen bonding interaction via phytic acid	Regenerated cellulose	PANI	2.5 × 10−2–6.8 × 10−1 S/cm	1.08–2.71 MPa	[128]
Chemical cross-linking via PPy grafted onto HA and polymerized afterward	HA	PPy	~7.3 × 10−3 S/cm	3 Kpa	[32]
Chemical cross-linking via acrylic acid and APS	Nanocrystalline cellulose	PPy	8.8 × 10−3 S/cm	4.16 Mpa	[129]
Graft-polymerization via acrylic acid	Chitosan	PPy	10−3 S/cm	N/A	[130]
Hydrogen bonding interaction via β-glycerophosphate	Chitosan	PPy	1.9–4.4 × 10−3 S/cm	N/A	[131]
Ion-interaction via calcium cations	Carboxymethyl chitosan/alginate	PPy	2.41 × 10−5–8.03 × 10−3 S/cm	N/A	[132]
Physical cross-linkers via CaCl2, MgCl2 and BaCl2	Carrageenan	PT	N/A	N/A	[11]
Chemical cross-linking via glutaraldehyde	Carboxymethyl chitosan/chitosan	PT	N/A	N/A	[73]

N/A: Not available; APS: ammonium persulphate; MPa: MegaPascal; KPa: kilopascal; S/cm: Siemens Per Centimeter.