Wearable sensors made of flexible and stretchable hydrogels have garnered significant attention. However, their use has been limited by poor mechanical performance, such as poor toughness, poor self-recovery, and a large response–recovery time. To overcome these limitations, we have developed a novel cross-linking agent-based hydrogel with high stretchability, high toughness, antifatigue properties, and good conductivity. These hydrogels were developed by introducing l-glutamic acid (LGA) into hydrophobically cross-linked polyacrylamide (PAmm) chains. In this system, LGA dynamically cross-linked the micelle–micelle and micelle–polymer chains and greatly regulates the mechanical properties of the hydrogels. The noncovalent synergistic interactions that came with the insertion of LGA enable the hydrogels to achieve high stretchability and high stress values, with fast self-recovery and antifatigue behaviors without the help of foreign stimuli. Additionally, LGA-based hydrogels can function as durable and highly sensitive strain sensors for detecting various mechanical deformations with a fast response–recovery time and high gauge factor value. As a result, the hydrogels have the capability to be designed as wearable strain sensors that are capable of detecting large human joint motions, such as neck twisting, neck bending, and wrist, finger, and elbow movements. Similarly, these hydrogels are capable of monitoring different subtle human motions such as speaking and differentiating between different words, swallowing, and drinking through larynx vibrations. Besides these large and subtle human motions, hydrogels have the ability to differentiate and reproduce different written words with reliability. These LGA-regulated hydrogels have potential applications in electric skins, medical monitoring, soft robotics, and flexible touch panels.

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Nonsteroidal anti-inflammatory hydrophobic drugs (NSAIDs) are amongst the most commonly given categories of drugs worldwide in the treatment of pain, irritation and some of them even fever in many conditions. Critical micelle concentration of NSAIDs with Naproxen sodium (NS) and its mixture with non-ionic surfactants i.e. Tween 20, Tween 40 and Tween 60 was investigated at 293 K, 303 K, 313 K and 323 K at different concentrations using surface tension and dynamic laser light scattering (DLS) techniques. Due to amphiphilic behaviour in aqueous solution NS form aggregates at sufficiently high concentration. Thermodynamic/adsorption properties like free energy of micellization (ΔGmic), enthalpy of micellization (ΔHmic), entropy of micellization (ΔSmic), Γmic and area per molecule (A2) of NS in the presence of surfactants were also measured at different temperatures. The results showed that the presence of surfactants favoured the ΔGmic and become more enhanced with increase in temperature. Further the solubility of drug is more favourable with increase in polyethylene chain in basic surfactant molecules i.e. 20–60, which indicates that Tween-60 enhanced the solubility of NS more comparatively to Tween-40 and Tween-20 and may be applied as best additive for solubilisation of NS.

In this study the synthesis of bi-phase nanoparticles of Fe1.46Zn0.5La0.04Cu0.5O4 (FZLCs) ceramics were first carried out by Sol-gel method and then nanocomposites of FZLCs with polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), polyethylene glycol (PEG) and polyethylene oxide (PEO) were prepared by one-pot blending technique. XRD, FT-IR, TG/DTA and SEM techniques were applied for complete characterization of composites. Rheological and dielectric properties of all nanocomposites were studied in detail for their comparative performance. TGA results reveal the highly thermal stability for all nanocomposites in this order i.e. FLZCs/PEO > FLZCs/PVA > FZLCs/PVP > FZLCs/PEG. Rheological properties show that these materials are rigid, pseudo plastic and non-Newtonian in nature. The increase in values for storage modulus (G′) and loss modulus (G′′) with increasing angular frequency owed to the shear thinning behavior of these nanocomposites. Dielectric properties show good agreement to that of energy storage substances which means that these materials have potential to be applied in storage devices.

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