Development of Membranes and Separators to Inhibit Cross-Shuttling of Sulfur in Polysulfide-Based Redox Flow Batteries: A Review.

The global rapid transition from fossil fuels to renewable energy resources necessitates the implementation of long-duration energy storage technologies owing to the intermittent nature of renewable energy sources. Therefore, the deployment of grid-scale energy storage systems is inevitable. Sulfur-based batteries can be exploited as excellent energy storage devices owing to their intrinsic safety, low cost of raw materials, low risk of environmental hazards, and highest theoretical capacities (gravimetric: 2600 Wh/kg and volumetric: 2800 Wh/L). However, sulfur-based batteries exhibit certain scientific limitations, such as polysulfide crossover, which causes rapid capacity decay and low Coulombic efficiency, thereby hindering their implementation at a commercial scale. In this review article, we focus on the latest research developments between 2012-2023 to improve the separators/membranes and overcome the shuttle effect associated with them. Various categories of ion exchange membranes (IEMs) used in redox batteries, particularly polysulfide redox flow batteries and lithium-sulfur batteries, are discussed in detail. Furthermore, advances in IEM constituents are summarized to gain insights into different fundamental strategies for attaining targeted characteristics, and a critical analysis is proposed to highlight their efficiency in mitigating sulfur cross-shuttling issues. Finally, future prospects and recommendations are suggested for future research toward the fabrication of more effective membranes with desired properties.

Enhanced physical properties of γ-Al2O3-rGO hybrids prepared by solvothermal and hot-press processing.

In this study, a solvothermal method was employed for the first time to fabricate hybrids composed of cross-linked γ-Al2O3 nanorods and reduced graphite oxide (rGO) platelets. After calcination and hot-press processing, monoliths of Al2O3-rGO hybrids were obtained with improved physical properties. It was found that the oxygen-containing groups on graphene oxide were beneficial for the adsorption of aluminum isopropoxide, leading to a uniform dispersion of rGO with Al2O3, which was obtained by hydrolysis of aluminum isopropoxide during the solvothermal reaction. The hybrid, which was subsequently calcinated for 3 h showed electrical conductivity of 6.7 × 101 S m-1 together with 90% higher mechanical tensile strength and 80% higher thermal conductivity as compared to the bare Al2O3. In addition, the dielectric constant of the hybrid was 12 times higher than that of the bare Al2O3. In this study, the highest values of electrical conductivity (8.2 × 101 S m-1), thermal conductivity (2.53 W m-1 K-1), dielectric constant (104) and Young's modulus (3.7 GPa) were obtained for the alumina-rGO hybrid calcinated for 1 h. XRD characterization showed that an increase in calcination temperature and further hot-press processing at 900 °C led to enhanced crystallinity in the γ-Al2O3 nanorods in the hybrid, resulting in enhanced physical properties in the hybrids.

Visible light photocatalytic water disinfection and its kinetics using Ag-doped titania nanoparticles.

The UN estimated about five million deaths every year due to water-borne diseases, accounting from four billion patients. Keeping in view, the ever increasing health issues and to undermine this statistics, a reliable and sustainable water-treatment method has been developed using visible light for water treatment. titania nanoparticles (NPs) have been synthesized successfully by a more applicable method Viz: liquid impregnation (LI) method. The bacterial death rate by photocatalysis under visible light was studied by employing a typical fluorescent source and was found to follow pseudo first-order reaction kinetics. The nanoparticles were characterized using X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray spectroscopy to deduce their size range, surface morphology, and elemental compositions, respectively. Among all the prepared grades, 1% Ag-TiO2 was found to be a very effective photocatalytic agent against Escherichia coli. The resulted photoinactivated data were also evaluated by different empirical kinetic models for bacterial inactivation. Hom, Hom-power, Rational, and Selleck models were not able to explain the disinfection kinetics but modified-Hom model fitted best with the experimentally obtained data by producing a shoulder, log-linear, and a tail region.

Impact of codon 72 Arg > Pro single nucleotide polymorphism in TP53 gene in the risk of kangri cancer: a case control study in Kashmir.

Kangri cancer found only in Kashmir (north India) is a unique thermally induced squamous cell carcinoma of the skin that develops because of chronic and persistent irritation due to the use of a kangri (a brazier) by the Kashmiri people to combat the chilling cold temperature during winter. Being unique to this region, the molecular etiology of the invasive kangri cancer is not known fully. The TP53 gene, codon 72 polymorphism (Arg72Pro), has been found to be associated with cancer susceptibility but has not been investigated in kangri cancer risk. A case control study was conducted to find the genotype distribution of TP53 Arg72Pro SNP and to elucidate the possible role of this SNP as risk factor in kangri cancer development. Using the polymerase chain reaction-restriction fragment length polymorphism approach, we tested the genotype distribution of 106 kangri cancer patients in comparison with 200 cancer-free controls from the same geographical region. A significant difference was observed between the control and kangri cancer patients with odds ratio = 2.02 and 95% confidence interval = 1.2-3.3 (p = 0.01). Interestingly, the proline form was abundantly observed in advanced-grade tumors (p < 0.05). We also found a significant association of the variant allele (GC + CC) with male subjects and patients >45 years of age (p < 0.05). Thus, it is evident from our study that Arg72Pro SNP is implicated in kangri cancer and that the rare, proline-related allele is connected with higher susceptibility to kangri cancer.

Mutational spectrum of conserved regions of TP53 and PTEN genes in Kangri cancer (of the skin) in the Kashmiri population.

Kangri cancer is a unique, thermally induced squamous cell carcinoma (SCC) of the skin that develops due to persistent use of a Kangri (a brazier) by the Kashmiri people to combat the cold temperature during winter. Unlike classical UV-induced SCC of the skin, Kangri cancer appears on the legs and abdomen. Its common features are erythematous patches, recurrence and metastasis. In the absence of any molecular etiology, we made a preliminary attempt to estimate the nature and frequency of mutations in the TP53 and PTEN genes in Kangri cancer patients from Kashmir. PCR-SSCP analysis followed by direct sequencing revealed that TP53 mutations account for 40% (12/30) of sporadic Kangri cancer patients and that PTEN mutations account for only 6.6% (2/30). There were 16 mutations in TP53 exons 5 and 7, found in 12 patients. They consisted of 11 substitutions (7 transitions, 3 transversions and 1 double-base) and 5 insertions. The 11 substitutions represent 8 distinct missense mutations, 3 of which were silent mutations. The mutations detected in the PTEN gene consisted of one insertion and one C>T transition. This high percentage of TP53 mutations (especially A>G) showed a statistically significant association with age and positive lymph node status. Our results indicate that TP53 is a predominant target of chronic hyperthermia in the development of Kangri cancer in the moderate risk Kashmiri population. The differences in the TP53 mutation spectrum of UV-induced SCC of the skin and Kangri cancer are probably due to the nature of the respective environmental carcinogens. The study also suggests that TP53 may function as a potential molecular marker and prognostic tool, at least in a subset of sporadic Kangri tumors.

Polymorphic analysis of MHClinked Heat Shock Protein 70 genes: Their susceptibility and prognostic implication in Kangri cancer cases of Kashmiri population.

Kangri cancer is a unique thermally-induced squamous cell carcinoma (SCC) of skin that develops due to persistent use of Kangri (a brazier), used by Kashmiri people, to combat the chilling cold during winter months. We designed a large scale case-control study to characterize the frequency of two polymorphisms within the MHC class III-linked HSP70genes, Hsp70-2 and Hsp70-hom, in order to find any association of these genotypic variants for predisposition to and clinical outcome of Kangri cancer patients from Kashmir valley in North India. Polymerase Chain Reaction and restriction enzymes were utilized to characterize the frequency of two polymorphisms with in Hsp70-2 and Hsp70-hom genes in 118 Kangri carcinoma cases and 95 healthy controls from the same population of Kashmir. Association of high frequency allelic variants of Hsp70genes with various clinicopathological features of prognostic significance was assessed by Chi-square test using SPSS software. In this study, allelic frequency of Hsp70-2 A/G heterozygote (0.87) (P = 0.012) was found to be significantly high in Kangri cancer cases compared to control (0.736) with a Relative Risk of 2.45 fold. Conversely, the allelic frequency of Hsp70-2 A/A allele in homozygous condition was significantly low in Kangri cancer cases and worked out to be 0.084 (Vs 0.252 in control) with P is equal to 0.001, implicating it as a protective allele against Kangri cancer in subjects with this genotype. Similarly, significantly high frequency of 0.50 (Vs 0.29 in control) of Hsp70-homC/C allele was found in homozygous condition in Kangri cancer cases suggestive of a positive relative risk associated with this genotype (RR is equal to 2.47) (P is equal to 0.002). The overall allele frequency data analysis of Hsp70-2 and Hsp70-hom genes was significant (chi(2) is equal to 12.38, P is equal to 0.002; and chi(2) is equal to 12.21, P is equal to 0.002). The study also reveals considerable association of high frequency alleles of HSP70 genes, especially of Hsp70-2 A/G or G/G in Kangri tumors with clinico-pathological features of poor prognosis. These results indicate that the relative risk of Kangri cancer associated with Hsp70-2 and Hsp70- hom gene polymorphisms is confined to Hsp70-2 A/G or G/G and Hsp70homC/C haplotype in our population. The study, therefore, suggests Hsp70-2 A/G or G/G and Hsp70homC/C genotypes as potential susceptibility markers and independent prognostic indicators in Kangri carcinoma patients in Kashmiri population.