Although Sn has been intensively studied as one of the most promising anode materials to replace commercialized graphite, its cycling performance and rate performance are still unsatisfactory owing to insufficient control of its large volume change during cycling and poor electrochemical kinetics. Herein, we propose a Sn-TiO2-C ternary composite as a promising anode material to overcome these limitations. The hybrid TiO2-C matrix synthesized via two-step high-energy ball milling effectively regulated the irreversible lithiation/delithiation of the active Sn electrode and facilitated Li-ion diffusion. At the appropriate C concentration, Sn-TiO2-C exhibited significantly enhanced cycling performance and rate capability compared to its counterparts (Sn-TiO2 and Sn-C). Sn-TiO2-C delivers good reversible specific capacities (669 mAh g-1 after 100 cycles at 200 mA g-1 and 651 mAh g-1 after 500 cycles at 500 mA g-1) and rate performance (446 mAh g-1 at 3000 mA g-1). The superiority of Sn-TiO2-C over Sn-TiO2 and Sn-C was corroborated by electrochemical impedance spectroscopy, which revealed faster Li-ion diffusion kinetics in the presence of the hybrid TiO2-C matrix than in the presence of TiO2 or C alone. Therefore, Sn-TiO2-C is a potential anode for next-generation Li-ion batteries.

We report a new fabrication method for a fully stretchable supercapacitor based on single wall carbon nanotube (SWCNT)-coated electrospun rubber nanofibers as stretchable supercapacitor electrodes. The deposition conditions of SWCNT on hydrophobic rubber nanofibers are experimentally optimized to induce a uniform coating of SWCNT. For surfactant-assisted coating of SWCNT, both water contact angle and sheet resistance were the lowest compared to the cases with other surface treatment methods, indicating the most effective coating approach. The excellent electromechanical properties of this electrode under the stretching condition is demonstrated by the measurement of Young’s modulus and normalized sheet resistance. This superb tolerance of the electrode with respect to stretching results from i) high aspect ratios of both nanofiber templates and the SWCNT conductors, ii) highly elastic nature of rubbery nanofiber, and iii) strong adherence of SWCNT-coated nanofiber on the elastic ecoflex substrate. Electrochemical and electromechanical measurements on the stretchable supercapacitor devices reveal that the volumetric capacitance (15.2 F cm-3 at 0.021 A cm-3) of the unstretched state is maintained for strains of up to 40 %. At this level of strain, the capacitance after 1,000 charge/discharge cycles is not significantly reduced. The high stability of our stretchable device suggests potential future applications in various types of wearable energy storage devices.

In recent years, cancer therapy has witnessed significant advancements, with a focus on personalized and targeted treatment strategies. One promising approach involves the use of stimuli-responsive biomaterials for site-specific drug release. Among these biomaterials, pH, and redox-triggered polymer-nano composites have gained immense attention due to their ability to respond to the specific tumor microenvironment, enhancing therapeutic efficacy while reducing off-target effects. Cancer cells often exhibit anomalous biochemical properties, attributed to lower cytosolic pH (acidic) and elevated redox potential through the epitomized upregulation of undesired genes. Such biological process substantially imbalance the level ions (protons) and biological thiols glutathione (GHS) in the cytoplasm as well as in the subcellular organelles. Superfluous accumulation of ions and redox imbalance is associated with proliferation, invasion, and growth of tumor. Because of high surface area, deep tissue penetration capability, higher hydrophilicity, hydrophobic interior for drug/gene efficient loading, biocompatibility and site-specific targeting efficiency, functionalized polymer nanocomposites are superior to conventional small molecular materials. Paradoxically conventional methods of drug delivery aided therapeutics accompanied with inherent drug/genes are encapsulated in biocompatible carrier or suitable transfecting agents generally suffered with low bioavailability, uncontrolled drug release, low cellular penetration, cellular internalization, toxicity, and poor drug loading efficiency. To overcome these issues, recently various multifunctional nanomaterials were developed, based on synergistic stimuli responsive aided drug release in a specified cellular or subcellular system. High therapeutic efficacy, of nanoparticles (NPs) mainly associated with surface functionalization through biocompatible polymeric materials, site-specific targeting units accompanied with stimuli responsive components. Followed by therapeutically important drug or genetic materials were loaded into NPs either in covalent or non-covalent approach. Intriguingly, combined pH and redox dual stimuli based functional materials specially based on polymeric nanocomposites for cancer therapeutics scarcely reported. This article provides the recent progress in pH and redox-responsive polymer-nano composites for site-specific drug delivery in cancer therapy. It explores design principles, fabrication methods, mechanism of action, and prospects of these dual-stimuli responsive biomaterials.