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•Advantages and drawbacks of phase change materials.•Supercooling is a shortcoming in phase change material’s practical applications.•Comprehensive discussion of supercooling ...mitigation techniques.•Different techniques for PCMs’ supercooling suppression were investigated.
In the quest for alternatives for fossil fuels, phase change materials (PCMs) have attracted considerable attention due to their ability to store renewable thermal energy. Compared to other storage systems, PCM systems are of low cost and capable of the storage of a high density of energy. However, few drawbacks hinder their practical application at an industrial scale. Among the drawbacks, supercooling problem affecting all types of PCMs is crucial. Supercooling as a shortcoming in PCM applications limits their practical applications. However, a comprehensive discussion or review articles have not been published. A PCM can exists in the liquid form below the phase change temperature or its freezing point, without fully freezing, due to supercooling. Thus, practical applications are limited by major problems such as the temperature variations and the increase of energy consumption. In this paper, most of the reported supercooling mitigation techniques for various types of PCMs and nanofluids are reviewed. These techniques are based mainly on adding nucleating agents (such as carbon nanotubes, fine salt particles, and nanoaditives), thickeners (such as carboxy methyl cellulose), and macroporous structures. The mitigation of phase separation and thermal cycling effects on supercooling are also discussed. The mitigation of supercooling in encapsulated organic PCMs, which is an important issue that is not very well understood, too is briefly addressed. Recommendations and future challenges to enhance the application of PCMs are discussed.
Recently, semiconductor photocatalysts for green hydrogen (H2) fuel require two-dimensional (2D) material with semiconducting direct bandgap and enhanced visible light absorptions. In this study, the ...first-principles calculation of the 2D layered nanostructure of SnGe2N4 is presented for photocatalysis applications, which has a direct bandgap of 1.73 eV/2.64 eV (Perdew–Burke–Ernzerhof/Heyd–Scuseria–Ernzerhof with generalized gradient approximation) with enhanced optical absorptions. The structure is checked to confirm the chemical formidability and dynamical steadiness by formation energy calculations and phonon dispersions. To attain the tunability of electronic and optical properties, biaxial strains, together with tensile and compressive strains, are incorporated, and it is found that compressive strain widens the bandgap, whereas tensile strain causes bandgap reduction. Biaxial strains also improve the optical absorption and the highest absorption coefficient is obtained at ∼1.47 ⨯ 105 cm−1 for 6% compressive strain, comparable to conventional perovskite materials. However, in the visible spectrum, the highest absorption coefficient is obtained for 6% tensile strain. The calculated photocatalytic band edges suggest that this material has sufficient kinetic overpotential for photo redox at compressive strains in both pH = 7 and pH = 0. In addition, the spatial carrier separation is achieved due to having a large intralayer effective potential deviation of ∼6.96 eV, as well as intralayer spatial atomic group contribution in the valance band maximum and conduction band minimum. Conclusively, the analysis in this study can be a theoretical background of this layered nanostructure as a potent photocatalyst for water splitting.
In this report, we discussed rapid, facile one-pot green synthesis of gold and silver nanoparticles (AuNPs and AgNPs) by using tuber extract of
, and evaluated their antibacterial activity. AuNPs and ...AgNPs were synthesized by mixing their respective precursors (AgNO
and HAuCl
) with tuber extract of
as the bio-reducing agent. Characterization of AuNPs and AgNPs were confirmed by applying UV-vis spectroscopy, field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), and energy dispersive X-ray spectroscopy (EDS). From UV-vis characterization, surface plasmon resonance spectra were found at 530 nm for AuNPs and 446 nm for AgNPs. XRD data confirmed that both synthesized nanoparticles were face-centered cubic in crystalline nature, and the average crystallite sizes for the assign peaks were 13.3 nm for AuNPs and 22.48 nm for AgNPs. FTIR data evaluated the characteristic peaks of different phytochemical components of tuber extract, which acted as the reducing agent, and possibly as stabilizing agents. The antibacterial activity of synthesized AuNPs and AgNPs were examined in Muller Hinton agar, against two Gram-positive and four Gram-negative bacteria through the disc diffusion method. AuNPs did not show any inhibitory effect, while AgNPs showed good inhibitory effect against both Gram-positive and Gram-negative bacteria.
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•Nano-conjugate adsorbent (NCA) is able to capture Pd(II) from acidic solution.•The color formation indicates the Pd(II) detection without using high-tech instruments.•The NCA has ...exhibited a high sorption capacity due to spherical nanosized cavities.•The NCA is reversible and reusable without any significant deterioration.
The functional group containing organic ligand of N,N(octane-1,8-diylidene)di(2-hydroxy-3,5-dimethylaniline) (DHDM) was developed and then successfully anchored onto mesoporous silica for the preparation of nano-conjugate adsorbent (NCA). After fabrication, the DHDM kept open functionality for capturing palladium (Pd(II)) under optimum conditions. The NCA exhibited the distinct color formation (π–π transition) after adding the Pd(II) ions both in solid and liquid states. The solution pH played an important role in the detection and sorption of Pd(II) but the prepared NCA worked well in the acidic pH region at 1.50. The data also clarified that the NCA did not form any color and signal intensity even in the presence of diverse ions except Pd(II). The determined limit of detection to Pd(II) ions was low as 0.14μg/L. In Pd(II) sorption, the affecting factors such as solution pH, kinetics, isotherm models, competing ions and elution/regeneration were studied in detail. The NCA confirmed the rapid sorption property and the maximum sorption capacity was 213.67mg/g due to spherical nanosized cavities with large surface area and pore volume. The base metal of Cu(II) and Zn(II) did not hamper the Pd(II) sorption ability of NCA in the acidic pH region. Therefore, it was expected that the Pd(II) could be separated from other hard metal ions by the NCA. The data also clarified that the other competing metal ions did not decrease the Pd(II) sorption capacity and NCA had almost no sorption capacity, which suggested the high selectivity of Pd(II) ions by NCA. The adsorbed Pd(II) was eluted with 0.20M HCl–0.20M thiourea eluent and simultaneously regenerated into the original form. The NCA was reversible and kept remaining functionality for reuse in many cycles after an extraction/elution process without significant deterioration. Therefore the proposed NCA can be considered as a potential candidate for Pd(II) capturing from waste samples.
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•Ligand immobilized conjugate adsorbent was prepared for Pb(II) capturing systems.•Adsorbent can be selectively captured the Pb(II) ions with high sensitivity.•Adsorbent exhibited ...spherical and nanosized cavities for high Pb(II) sorption.•Adsorbent is reversible and reusable without loss from its original performances.
Lead (Pb(II)) is a very toxic heavy metal that even at low concentration can affect living organisms. Therefore, designing effective materials with high selectivity and cost-effeciency is essential for the control capturing of toxic Pb(II) ions. This study developed a ligand based conjugate adsorbent for simultaneous Pb(II) detection and removal from water samples. The organic ligand of 4-dodecyl-6-((4-(hexyloxy)phenyl)diazenyl) benzene-1,3-diol (DPDB) was synthesized and DPDB was successfully immobilized onto mesoporous silica by a direct immobilization approach. The Pb(II) ion was detected by the charge transfer (π–π transition) transduction mechanism with sensitivity and selectivity. The experiment conditions were optimized based on contact time, solution acidity, initial Pb(II) concentration and pH value and diverse metal salt concentrations. The adsorbent was highly sensitive, and the limit of detection was 0.18μg/L for Pb(II) ions. The Pb(II) sorption synthetic aqueous solution also underwent batch tests. However, the sorption capacity depended on the solutions pH, initial concentration and to some extent on the competing ions. The experimental data revealed that the maximum Pb(II) sorption was possible at pH 5.0. The presence of other cations and anions did not adversely affect the Pb(II) capturing by the adsorbent. The maximum sorption capacity was determined to be as high as 195.31mg/g. The extraction of Pb(II) ions from the saturated adsorbent was possible with 0.20M HCl. The regenerated adsorbent that remained maintained the high selectivity to Pb(II) ions and exhibited almost the same sorption capacity as that of the original adsorbent. However, the sorption efficiency slightly decreased after ten cycles. Therefore, the proposed adsorbent offered a cost-effective material and may be considered a viable alternative for effectively monitoring and removing toxic Pb(II) ions from water samples without the need for sophisticated instrument.
The water pollution caused by industrial effluents of pollutant dyes has been harmfully affected to the human health and environment. Therefore, it is important for considerable attention to remove ...them from industrial wastewater before being discharged to the surface water. The natural polymer-based carbohydrate adsorbent with specific functional groups can be enhanced their potential applications toward the notorious dyes removal from wastewater. In this regard, we selected natural adsorbent of graham flour (GF) as an effective adsorbent to remove cationic crystal violet (CyV) dye by the adsorption method. The morphology and structure of GF was characterized in systematic manner by several instrumentations. The several influencing factors such as solution pH, contact time, dose amount, maximum adsorption capacity, competing metal ions effect and reuses behavior were systematically measured. The effective pH range for CyV adsorption was neutral pH region and the maximum adsorption capacity of the GF adsorbent was as high as 162.33 mg/g. The data also clarified that the polymeric GF adsorbent was selectively removed the CyV dye from synthetic polluted sample even in the presence of high concentration of diverse competing ions. The adsorbed CyV dye was eluted with ethanol and simultaneously regenerated into initial form for the next adsorption operations after rinsing with water. Importantly, the natural GF adsorbent was retaining functionality in spite of many steps during adsorption-elution-regeneration cycles. Therefore, the present study revealed that such a low-cost natural polymeric carbohydrate adsorbent could be used as potential adsorbent for the selective dye molecules from wastewater streams.
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•Biodegradable natural carbohydrate polymeric adsorbent was used for toxic dye removal.•The adsorbent was exhibited high adsorption capacity with immense sensitivity.•The adsorbent was able reuses in several cycles with loss in its initial performances.
The toxic anionic dye of methyl orange encapsulation was studied using biodegradable natural carbohydrate polymeric adsorbents of rice flour (RF) and graham flour (GF). The adsorbents were ...characterized by several instrumentations to understand the functionality and potential use. The dye adsorption parameter was measured based on the solution acidity, contact time, initial concentration effect, competing anions affinity, bonding mechanism, maximum adsorption capacity and reuses with biodegradability. The solution acidity was exhibited the key factor, and the suitable pH 7.0 and 5.50 were selected for RF and GF adsorbent, respectively based on the efficiency. The competing ions were not adversely affected in the dye adsorption as defined by the stable bonding mechanism. The adsorption data were highly fitted with the Langmuir adsorption model with monolayer coverage. The determined maximum adsorption was 173.24 and 151.27 mg/g for RF and GF, respectively, which was comparable with the other forms of materials. The desorption data was promising as the RF and GF adsorbents were used several cycles and therefore, the biodegradable adsorbents are promising to use in the real sample treatment to clean up the contaminated water.
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•Exploring potential use of biodegradable natural carbohydrate polymers for toxic dye removal.•Adsorption efficiency and effectiveness were measured by the all adsorbents.•Encapsulating mechanism and appropriates of the adsorbent were evaluated.
•A novel ligand-embedded composite adsorbent was proposed for Sm(III) ion separation.•The functional groups were coordinated with Sm(III) in a stable complexation mechanism.•The surface of the ...composite adsorbent was open and stable for multiple-cycle uses.
The novel organic compound of ammonium (4-chlro-2-mercaptophenyl)carbamodithioate (ACMPC) was prepared and then subsequently grafted onto the mesoporous silica by direct approach for the preparation of composite adsorbent (CPA). The lanthanide (Ln(III)) intra-series separation behavior was measured using CPA and then the samarium (Sm(III)) ion was selected according to the high adsorption ability by CPA for effective separation, adsorption, and recovery in the solid-liquid approach. The mesoporous silica and CPA were characterized systematically for the evaluation of affecting experimental criterion. The solution acidity played an important factor as the alkaline pH area was avoided due to the hydroxide precipitation probability and pH 5.0 was selected for selective and effective Sm(III) ion separation and recovery. The data clarified that CPA exhibited high kinetic performances with high adsorption ability. The Sm(III) adsorption was highly fitted with the Langmuir adsorption isotherm model with monolayer coverage and the maximum adsorption capacity was determined as 155.13 mg/g. In addition, the diverse foreign ions were not reduced the Sm(III) ion adsorption significantly, and the CPA has approximately no adsorption capacity for other ions at this pH. The Sm(III) ion was strongly coordinated with the ACMPC and the expected highly stable complexation mechanism with the soft donor of N- and S- atoms. The elution of Sm(III) ions from the saturated CPA was desorbed successfully with 0.30 M HNO3. The regenerated CPA that remained maintained the high selectivity to Sm(III) ions and exhibited almost the same adsorption capacity as that of the original CPA. Therefore, the proposed CPA offered a cost-effective material and may be considered a viable alternative for effectively Sm(III) ion separation and recovery from waste samples as potential materials.
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We propose a simple hollow-core circular lattice photonic crystal fiber (PCF) based surface plasmon resonance (SPR) refractive index sensor. The sensing performance is investigated by using the ...finite element method (FEM). Silver is used as the plasmonic material for this design, which is placed on the outer surface of the PCF to facilitate the fabrication. The proposed sensor shows a maximum wavelength sensitivity of 4200 nm/RIU with a sensor resolution of 2.38 × 10−5 RIU. Besides, a maximum amplitude sensitivity of 300 RIU−1 and a resolution of 3.33 × 10−5 RIU is reported for an analyte refractive index of 1.37. Moreover, the effect of varying structural parameters on the sensing performance such as pitch, air hole diameter and silver layer thickness are also discussed thoroughly. Sensitivity analysis of the proposed sensor is performed in order to investigate the impact on loss depth and amplitude sensitivity. Thanks to high sensitivity and linearity characteristics, the proposed sensor can be potentially employed in practical bio-sensing and chemical sensing applications.
•A circular lattice hollow-core PCF based plasmonic sensor is proposed.•Maximum wavelength sensitivity of 4200 nm/RIU is reported.•The sensor length can be extended due to very low confinement loss.•Insignificant impacts on performance due to the variation of structural parameters.•Detection process of analyte is straightforward because of external metal coating.
Tilapia Lake Virus (TiLV) is a disease that affects tilapia fish, causing a high rate of sudden death at any stage in their life cycle. Unfortunately, there are currently no effective antiviral drugs ...or vaccines to prevent or control the progression of this disease. Researchers have discovered that the CRM1 protein plays a critical function in the development and spreading of animal viruses. By inhibiting CRM1, the virus's spread in commercial fish farms can be suppressed. With this in mind, this study intended to identify potential antiviral drugs from two different tropical mangrove plants from tropical regions: Heritiera fomes and Ceriops candolleana. To identify promising compounds that target the CRM1 protein, a computer-aided drug discovery approach is employed containing molecular docking, ADME (absorption, distribution, metabolism and excretion) analysis, toxicity assessment as well as molecular dynamics (MD) simulation. To estimate binding affinities of all phytochemicals, molecular docking is used and the top three candidate compounds with the highest docking scores were selected, which are CID107876 (-8.3 Kcal/mol), CID12795736 (-8.2 Kcal/mol), and CID12303662 (-7.9 Kcal/mol). We also evaluated the ADME and toxicity properties of these compounds. Finally, MD simulation was conducted to analyze the stability of the protein-ligand complex structures and confirm the suitability of these compounds. The computational study demonstrated that the phytochemicals found in H. fomes and C. candolleana could potentially serve as important inhibitors of TiLV, offering practical utility. However, further in vivo investigations are necessary to investigate and potentially confirm the effectiveness of these compounds as antiviral drugs against the virus TiLV.
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