A brief review on preparation and application of MWCNT-based polymer nanocomposites

Technological advancementalways seeks new materials with improved functional properties, particularly for smart applications. In this regard, nanotechnology is offering today wide range of novel material designs fabricated by compounding nanofillers into the polymer matrix. Different allotropic forms of carbon can reinforce the properties of polymers for various applications. Reinforcement depends on the dimension, shape, size and compatibility of the nanofiller with the polymer matrix. Chemical modification of filler surfaces and the matrix can selectively localize the filler in the hybrid composites in the desired phase or at the interface by melt mixing or solution casting method, during compounding procedure. In this regard, the conducting nature of the additioin of multiwalled carbon nanotubes (MWCNTs) into a polymer matrix fosters the conductivity into the materials. Such nanocomposites can be used for numerous applications such as conducting materials, super-capacitors, light emitting devices, medical purposes etc,. This review paper focuses on different methods of preparation of MWCNT/polymer nanocomposites, their surface properties, and microbial properties etc,

A brief review on preparation and application of MWCNT-based polymer nanocomposites

Technological advancementalways seeks new materials with improved functional properties, particularly for smart applications. In this regard, nanotechnology is offering today wide range of novel material designs fabricated by compounding nanofillers into the polymer matrix. Different allotropic forms of carbon can reinforce the properties of polymers for various applications. Reinforcement depends on the dimension, shape, size and compatibility of the nanofiller with the polymer matrix. Chemical modification of filler surfaces and the matrix can selectively localize the filler in the hybrid composites in the desired phase or at the interface by melt mixing or solution casting method, during compounding procedure. In this regard, the conducting nature of the additioin of multiwalled carbon nanotubes (MWCNTs) into a polymer matrix fosters the conductivity into the materials. Such nanocomposites can be used for numerous applications such as conducting materials, super-capacitors, light emitting devices, medical purposes etc,. This review paper focuses on different methods of preparation of MWCNT/polymer nanocomposites, their surface properties, and microbial properties etc,

Chemical profiling, antioxidant, and antimicrobial activities of the essential oil of Matricaria recutita (Chamomile)

Matricaria recutita, commonly known as chamomile, is extensively utilized in the pharmaceutical, cosmetic, and food industries for its medicinal and essential oil properties. Local people from the Karnali Province of Nepal use this plant against skin and vaginal infection by bacteria and fungi. This research focuses on extracting essential oil through hydro-distillation, followed by Gas Chromatography-Mass Spectroscopy (GC-MS) to identify its chemical constituents and antioxidant and antimicrobial activities against bacteria and fungi responsible for common skin infections. The GC-MS analysis of the essential oil from M. recutita identified eleven chemical components. The major constituents, with respective area percentages at retention times 37.16, 11.79, and 7.88 in the GC chromatogram, were -farnesene (46.56%), -bisabolol oxide-A (11.79%), and menthol (7.88%). Limonene, methyl salicylate, and -bisabolol oxide-B also constituted the lowest area percentages at 1.36%, 1.59%, and 1.62%, respectively. The essential oil exhibited significant antioxidant activity with IC50 = 0.1924 µL/mL. Additionally, the essential oil exhibited notable antibacterial activity against Staphylococcus aureus ATCC6538P and Candida albicans, displaying zones of inhibition measuring 10.64 mm and 14.44 mm, respectively. The broth method also revealed that the MIC is above the 250 mg/mL range and has more potential for inhibition

Influence of Controlled Epoxidation of an Asymmetric Styrene/Butadiene Star Block Copolymer on Structural and Mechanical Properties

The chemical modification (namely the epoxidation) of a star shaped block copolymer (BCP) based on polystyrene (PS) and polybutadiene (PB) and its effect on structural and mechanical properties of the polymer were investigated. Epoxidation degrees of 37 mol%, 58 mol%, and 82 mol% were achieved by the reaction of the copolymer with meta-chloroperoxy benzoic acid (m-CPBA) under controlled conditions. The BCP structure was found to change from lamellae-like to mixed-type morphologies for intermediate epoxidation level while leading to quite ordered cylindrical structures for the higher level of chemical modification. As a consequence, the glass transition temperature (Tg) of the soft PB component of the BCP shifted towards significantly higher temperature. A clear increase in tensile modulus and tensile strength with a moderate decrease in elongation at break was observed. The epoxidized BCPs are suitable as reactive templates for the fabrication of nanostructured thermosetting resins

Pyrolyzed human hair: a review on synthesis, characterization and applications

Human hair, a common biowaste, can be pyrolyzed to prepare many kinds of functional materials. Pyrolyzed hair has been used in various forms of traditional medicine, sensor, ink, and electrolytes. This review highlights the major structural characteristics of human hair and its pyrolyzed form. It also addresses the characterization techniques used for the structure elucidation of pyrolyzed human hair as well as its potential applications. BIBECHANA 18 (1) (2021) 231-23

Pyrolyzed human hair: a review on synthesis, characterization and applications

Human hair, a common biowaste, can be pyrolyzed to prepare many kinds of functional materials. Pyrolyzed hair has been used in various forms of traditional medicine, sensor, ink, and electrolytes. This review highlights the major structural characteristics of human hair and its pyrolyzed form. It also addresses the characterization techniques used for the structure elucidation of pyrolyzed human hair as well as its potential applications. BIBECHANA 18 (1) (2021) 231-23

Physicochemical and Structural Investigation of Argeli (Edgeworthia gardneri) Bast Fibers

The structure and some physicochemical properties of Argeli (Edgeworthia gardneri) bast fibers were investigated using Fourier Transform Infrared (FTIR) and Energy Dispersive X-ray (EDX) spectroscopies, Optical Microscopy (OM) and Scanning Electron Microscopy (SEM). The neat fibers were found to contain about 54.47% cellulose, 25.98% hemicellulose, 10.5 % lignin, 6.1% extractives, and about 2.9% ash. The fibers on chemical treatments changed several properties, some of them being quite significant. Fiber density was increased by 8.5% in the alkali-treated samples which may be due to the loss of less dense components such as lignin and hemicelluloses. The tensile strength of the fiber increased by 34 % and 61 %, respectively, after alkali and bleaching treatments. However, the thermal properties of treated samples did not change significantly. The mechanical properties of Argeli fiber were improved on chemical treatments making them attractive in the fabrication of polymer composites, textiles, and papers

Traditional, video and extended reality (XR) assisted flipped classroom teaching methods:an approach and comparison

This paper examines the comparative effectiveness of three distinct Flipped Classroom (FC) teaching methods in the context of Power and Electrical (PE) engineering education: Traditional Flipped Classroom (TFC), Video-Assisted Teaching Methods (VAFC), and Virtual Reality Flipped Classroom (VRFC). The study incorporates valuable feedback from students who experienced these methods and provides an evaluation of their perceptions. A cross-over methodology for comparing these FC methods is presented. The VAFC method is perceived to be an effective approach and preferred over TFC and VRFC by students. The paper also provides Teachers' perception in implementing above FC methods, which outlines a process for developing VAFC and VRFC teaching resources. Operational difficulties in implementing such methods are highlighted, especially in the context of fast-paced, privately-catered undergraduate education sector striving for implementing non-conventional teaching methods

Natural dyes as photo-sensitizer in solar cells

The objective of this research is to employ the natural dyes in dye-sensitized solar cell (DSSC). On account of eco-friendly, renewable, and non-hazardous properties of natural dyes over silicon, a semiconductor, photo-sensitizer in conventional solar cells,  cyclohexane extract of Terminalia alata, a natural dye, was employed as photo-sensitizer. The photoanodes ZnO and 5% Al-doped ZnO for DSSCs were developed by spray pyrolysis. The X-ray diffraction (XRD) has shown hexagonal wurtzite structure of ZnO with lattice constants a = 3.2487 Å and b = 5.1518 Å having particle size 25.85 nm for ZnO and 33.17 nm for Al-doped ZnO. The DSSC properties such as solar conversion efficiency (η), short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF) were found to be 0.31%, 2.10 mA/cm2, 0.73V, and 45% for ZnO photoanode and 0.37%, 2.25mA/cm2, 0.70 V, and 52.10% for 5% Al-doped photoanode respectively. BIBECHANA 17 (2020) 27-3

Natural dyes as photo-sensitizer in solar cells

The objective of this research is to employ the natural dyes in dye-sensitized solar cell (DSSC). On account of eco-friendly, renewable, and non-hazardous properties of natural dyes over silicon, a semiconductor, photo-sensitizer in conventional solar cells,  cyclohexane extract of Terminalia alata, a natural dye, was employed as photo-sensitizer. The photoanodes ZnO and 5% Al-doped ZnO for DSSCs were developed by spray pyrolysis. The X-ray diffraction (XRD) has shown hexagonal wurtzite structure of ZnO with lattice constants a = 3.2487 Å and b = 5.1518 Å having particle size 25.85 nm for ZnO and 33.17 nm for Al-doped ZnO. The DSSC properties such as solar conversion efficiency (η), short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF) were found to be 0.31%, 2.10 mA/cm2, 0.73V, and 45% for ZnO photoanode and 0.37%, 2.25mA/cm2, 0.70 V, and 52.10% for 5% Al-doped photoanode respectively. BIBECHANA 17 (2020) 27-3