Preparation of La0.7Ca0.3Mn0.95Fe0.05O3 perovskites by different methods: Catalytic activity towards the hydroxylation of benzene

Nanoparticles of the La0.7Ca0.3Mn0.95Fe0.05O3 perovskites were synthesized by various wet chemical routes, namely, co-precipitation, oxalate-gel and citrate-gel methods. Phase formation and crystal structure of the synthesized powders were examined by the X-ray diffraction (XRD). The morphology was evaluated by the scan electron microscopy (SEM). Infrared transmission spectroscopy revealed that stretching and bending modes were influenced by the preparation methods. The citrate gel method yielded better powder properties. The prepared perovskite samples were used in the oxidation of benzene. The highest activity for the catalytic oxidation of benzene to phenol in presence of hydrogen peroxide (H2O2) was obtained with the citrate-gel prepared sample

Ti3C2Tx-Au hybrid composites-based electrochemical biosensors for calreticulin biomarker detection

A sensitive biosensor is critical for early breast cancer treatment and prognosis. Herein, a label-free electrochemical immunosensor is proposed for the sensitive detection of calreticulin (CALR), a new breast cancer biomarker. The biosensor relied upon an electroactive hybrid of ultra-thin Ti3C2Tx nanosheets preadsorbed with Au NPs and methylene blue (MB)(MB–Ti3C2Tx–Au), which served as redox-active centers and an electroactive probe to detect CALR biomarkers respectively. The detection mechanism followed a simple inhibition strategy, where the optimal differential pulse voltammetry (DPV) response of preadsorbed MB over the Ti3C2Tx–Au electrode decreased in proportion to the concentration of CALR biomarkers owing to the formation of the antibody-antigen immunocomplex. The biosensor could detect CALR-biomarker in the concentration range of 0.0015 to 0.94 ng mL−1 with a limit of detection (LOD) of 0.28 pg mL−1 and showed excellent antifouling properties against commonly encountered biomolecules such as hemoglobin (Ig), immunoglobulin G (IgG), neuron-specific enolase (NSE), and tumor necrosis factor-alpha (TNF). The proposed strategy provides an efficient method for utilizing MXene nanosheets to construct advanced biosensors with promising clinical applications

Viscoelastic and Properties of Amphiphilic Chitin in Plasticised Polylactic Acid/Starch Biocomposite

The enhancement of the PLA thermomechanical properties is significant due to its suitability as a replacement for primary synthetic polymer use in diverse industrial production. The amphiphilic chitin was used as a compatibilizer in PLA/starch biocomposite. The properties of plasticised polylactic acid blended with starch, and amphiphilic chitin was studied for enhanced thermomechanical and viscoelastic properties. Chitin was modified using acetylated substitution reaction and blended with plasticised PLA/starch biocomposite. The biocomposite was prepared with combined compression and melt extrusion techniques. The biocomposite’s thermomechanical, thermal, mechanical, and morphological properties were studied using dynamic mechanical analysis, TGA-DSC, tensile test, and scanning electron microscopy. The storage and loss modulus were significantly enhanced with increased amphiphilic chitin content. Similarly, the single peak of tan delta showed good miscibility of the polymeric blend. Additionally, the modulus increases with frequency change from 1 Hz to 10 Hz. The thermal stability of the biocomposite was observed to be lower than the neat PLA. The tensile properties of the biocomposite increased significantly more than the neat PLA, with P4S4C having the highest tensile strength and modulus of 87 MPa and 7600 MPa. The SEM images show good miscibility with no significant void in the fractured surface. The viscoelastic properties of PLA were enhanced considerably with plasticizer and amphiphilic chitin with improved biodegradability. The properties of the biocomposite can be adapted for various industrial applications

Progress and current challenges for CO2 capture materials from ambient air

As a major component of greenhouse gases, excessive carbon dioxide (CO2) in the atmosphere can affect human health and ecosystems. Therefore, the capture and transformation of CO2 has attracted extensive attention in academic circles in recent years. Direct air capture (DAC) of CO2 is a technology developed in recent years that can capture and collect CO2 directly from the ambient air, which is a potential negative CO2 emission technology. Currently, DAC technology is being promoted worldwide. Therefore, given the lack of a timely review of the latest developments in DAC technology, an appropriate and timely summary of this technology and a comprehensive understanding of it is necessary. In this paper, we review the research progress of adsorbent materials for directly capturing CO2 from ambient air in recent years, including liquid-based absorbent, solid adsorbent, and moisture-swing adsorbent. How their chemical composition, structure, morphology, modification method affects their performance and long-term use is thoroughly discussed. In addition to efficient CO2 adsorption properties, designing low-cost sustainable materials is critical, especially for practical applications. Therefore, the technical and economic evaluation of CO2 adsorbents directly capturing from ambient air is reviewed. This review is of great significance for researchers to fully understand the development status and future trends of direct capture of CO2 from ambient air

Overview of biomass valorization: Case study of nanocarbons, biofuels and their derivatives

With the increasing awareness of the serious pollution from the usage of fossil fuels and the fast advances of technologies, the usage of biomass has been increased significantly. In this review paper, the biomass serving as carbon precursors and the energy has been reviewed including lotus lives, wheat flour, fish scale, fish skin, wax gourd, etc. The formed carbon nanostructures are reviewed together with their applications including the treatment volatile organic compounds (VOCs), heavy metal ions from polluted water, spilled oil, fillers for advanced composites, etc. This paper gives the usage of biomass in a sustainable and green way

Waterborne acrylic resin co-modified by itaconic acid and γ-methacryloxypropyl triisopropoxidesilane for improved mechanical properties, thermal stability, and corrosion resistance

The waterborne acrylic resin modified by both itaconic acid (IA) and γ-methacryloxypropyl triisopropoxidesilane (KH571) was successfully synthesized by the seeded emulsion polymerization. The effects of IA and KH571 on the properties of waterborne acrylic resin, including mechanical properties, water resistance, thermal stability, storage stability and corrosion resistance, were studied. Fourier transform infrared spectroscopy analysis showed that IA and KH571 were successfully copolymerized with acrylic monomers. Compared with the unmodified resin, the introduction of IA and KH571 greatly improved the water resistance of the resin coating. When 2 wt% IA and 4 wt% KH571 were added, the contact angle of the resin coating increased from 78.91° to 90.49°. The water resistance time of the resin coating was improved from one day to 17 days. Additionally, the modified resin showed better mechanical properties, thermal stability, storage stability and corrosion resistance. The waterborne acrylic resin modified with IA and KH571 has a potential application prospect in the fields of waterproof and anticorrosive coating

Comprehensive Biological Potential, Phytochemical Profiling Using GC-MS and LC-ESI-MS, and In-Silico Assessment of <i>Strobilanthes glutinosus</i> Nees: An Important Medicinal Plant

Plants of the genus Strobilanthes have notable use in folklore medicines as well as being used for pharmacological purposes. The present work explored the biological predispositions of Strobilanthes glutinosus and attempted to accomplish a comprehensive chemical profile through GC-MS of different fractions concerning polarity (chloroform and n-butanol) and LC-ESI-MS of methanolic extract by both positive and negative ionization modes. The biological characteristics such as antioxidant potential were assessed by applying six different methods. The potential for clinically relevant enzyme (α-amylase, α-glucosidase, and tyrosinase) inhibition was examined. The DPPH, ABTS, CUPRAC, and FRAP results revealed that the methanol fraction presented efficient results. The phosphomolybdenum assay revealed that the n-hexane fraction showed the most efficient results, while maximum metal chelation potential was observed for the chloroform fraction. The GC-MS profiling of n-butanol and chloroform fractions revealed the existence of several (110) important compounds presenting different classes (fatty acids, phenols, alkanes, monoterpenes, diterpenes, sesquiterpenoids, and sterols), while LC-ESI-MS tentatively identified the presence of 44 clinically important secondary metabolites. The n-hexane fraction exhibited the highest potential against α-amylase (497.98 mm ACAE/g extract) and α-glucosidase (605.85 mm ACAE/g extract). Significant inhibitory activity against tyrosinase enzyme was displayed by fraction. Six of the prevailing compounds from the GC-MS study (lupeol, beta-amyrin, stigmasterol, gamma sitosterol, 9,12-octadecadienoic acid, and n-hexadecanoic acid) were modelled against α-glucosidase and α-amylase enzymes along with a comparison of binding affinity to standard acarbose, while three compounds identified through LC-ESI-MS were docked to the mushroom tyrosinase enzyme and presented with significant biding affinities. Thus, it is assumed that S. glutinosus demonstrated effective antioxidant and enzyme inhibition prospects with effective bioactive molecules, potentially opening the door to a new application in the field of medicine