Reinforcing effect of oxidized multiwalled carbon nanotubes on swelling and mechanical properties of gum ghatti-cl-poly(NIPAm-co-AA) hydrogels

The objective of the present study was to synthesize Gg-cl-poly(NIPAm-co-AA)/-o-MWCNT (GNACNT) hydrogel via free radical copolymerization using the following ingredients: gum ghatti as biopolymer (GG), acrylic acid (AA) as a probe for synthetic monomer, ammonium persulphate as initiator, and methylene bis-acrylamide (MBA) as cross-linker. This hydrogel shows superior mechanical performance by incorporating filler such as oxidized multiwalled carbon nanotubes (-o-MWCNT) in varying quantities (0–50 mg) to produce polymer/inorganic composite hydrogels which has one of the most promising ways for improving the mechanical characteristics of hydrogels. In the linear viscoelastic region, the storage modulus (G′) was much higher than the loss modulus (G″) for all hydrogels across the entire frequency range. The persistent covalence crosslinking is responsible for the solid-like behaviour and elastic nature (G′ > G″). When additional -o-MWCNT was added, G′ was found to be increased. The -o-MWCNT’s interaction became stronger when the MWNT dispersion quality improved or their network connections, aspect ratio, or concentration rose, as shown by a greater storage modulus G, complex viscosity |η*|, and constant shear viscosity. Suspensions containing a combination of separated -o-MWCNT aggregates and small -o-MWCNT aggregates displayed G′ that was independent of frequency, indicating solid-like behaviour. As a result, these hydrogels may have potential uses in biological disciplines that are not limited by water capacity or mechanical qualities.