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Due to the amphiphilic structure of surfactants, aqueous surfactant solutions can behave like very good solvents and dissolve both polar and non-polar solutes. This study reports on the solubilisation of a direct dye (Direct Blue 86) in a micellar medium using the cationic surfactant cetyltrimethylammonium bromide (CTAB). Solubilisation of dyes is important for their subsequent removal from aqueous media. UV spectroscopy and conductometry, among others, were used to quantitatively evaluate this process. The extent of solubilisation, the interaction between the molecules and the stability of the processes were checked using the partition coefficient (K x), the binding constant (K b) and the corresponding thermodynamic parameters. From the results, it could be concluded that the solubilisation of Direct Blue 86 is a spontaneous process supported by an increase in entropy. It was also found that the micellar medium CTAB is efficient for solubilisation and binding of the dye and can be used economically.

Background: Betti bases are pharmaceutically and synthetically important scaffolds due to their diverse range of biological activities and applications in key synthetic transformations in organic synthesis. Objective: This work has been sought to contribute to the development, design, and implementation of an improved green methodology with higher atom economy and lower E-factor values for the synthesis of Betti bases. Method: To realize our objectives, we screened out different catalysts and reaction conditions using one-pot multicomponent modified Mannich reaction/Betti reaction by employing 2-naphthol, benzaldehyde and pyrrolidine as model substrates. Results: The developed methodology afforded functionalized Betti bases in 60-100% yields via FeCl3•6H2O catalyzed one-pot multi-component Betti reaction under neat conditions at 110 °C (5-15 min) using several aromatic aldehydes and secondary amines. Conclusion: A facile synthetic methodology with higher atom economy and lower E-factor values to synthesize Betti bases via FeCl3•6H2O catalyzed one-pot multicomponent Betti reaction of 2-naphthol, aromatic aldehydes, and secondary amines under neat conditions at 110 °C has been reported. The developed methodology offers various advantages, such as excellent yields (60-100%), short reaction time (5-15 min), wide substrate scope (12 examples), green reaction conditions, use of readily available catalyst, and easy purification (without column chromatography).

Data Availability: Data will be made available on request. Appendix A. Supplementary material available online at https://www.sciencedirect.com/science/article/pii/S2211285522011909?via%3Dihub#sec0065 Copyright © 2022 The Author(s). High-specification nanofluids can potentially enable cost-effective and highly efficient solar-to-thermal energy conversion. However, their implementation is adversely affected by poor absorption spectral range and stability challenges of the nanoparticles. Here we demonstrate the synthesis, full characterization and application of Cu-oxide nanoparticles with high optical absorption and long-term stability over many months. The synthesis method, based on a hybrid plasma-liquid non-equilibrium electrochemical process, ensures a very limited environmental impact as it relies on a solid metal precursor while avoiding the use of additional chemicals such as surfactants and other reducing agents. We further investigate the fundamental links between the nanofluid performance and the material and optical properties and produce a theoretical model to determine the energy conversion efficiency. The results show that nanofluids produced with our Cu-oxide nanoparticles can achieve exceptional solar thermal conversion efficiencies close to ∼90% and can provide a viable solution for an efficient solar thermal conversion technology. EPSRC (award no. EP/M024938/1, EP/V055232/1, EP/R008841/1).

The present study was focused on the preparation of cobalt oxide (CoO) and barium doped cobalt oxide (Ba doped CoO) by following co-precipitation method for the degradation of Emamectin benzoate pesticide in aqueous medium. The prepared catalysts were characterized using SEM, EDX and XRD to confirm the formation of catalysts and to observe the variation in the composition of catalysts during degradation study. The degradation of Emamectin benzoate pesticide was studied under the influence of different factors like solution pH, dose of catalyst, contact time, temperature and initial concentration of pesticide. It was observed that solution pH affects the degradation of pesticide and maximum degradation was found at pH 5 and 6 using CoO and Ba doped CoO respectively. The degradation of pesticide was found to be increases continuously with time of contact and decreases with increase in temperature. Likewise, at the beginning, degradation was observed to be increases up to some extent with dose of catalyst and initial concentration of pesticide but started decreases with further augmentation in the dose of catalyst and initial concentration of pesticide. It may be concluded from this study that doping of Ba considerably enhanced the photocatalytic ability CoO for Emamectin benzoate pesticide.

Growing industry and its effluents create a serious environmental concern. Various industrial wastes such as toxic dyes and volatile organic compounds are posing a threat to a clean environment because of their non-biodegradable nature and high chemical stability. In recent years, the degradation of toxic dyes and drugs by photo-catalysts has gained much importance and proved a successful approach to capture light by hybrid photo-catalysts for decomposing toxic organic molecules. This work presents the synthesis of a poly(o-anisidine)-based composite with graphitic carbon nitride and zinc oxide (POA/g-C3N4/ZnO) and its utilization as a photo-catalyst. Various analytical techniques investigated the synthesized photo-catalysts’ chemical structure, crystallinity, and morphology. The degradation of Congo red dye evaluated the efficiency of the photo-catalyst in an aqueous medium under ultraviolet light. It was revealed that the photo-catalytic activity of the synthesized POA/g-C3N4/ZnO composites show 81.43%, 92.28%, and 87.05% degradation. This sustainable composite will be highly beneficial to treat industrial wastewater to make our environment clean.

The supply chain structure of the pharmaceutical industry in Pakistan was investigated in this research study. It was hypothesized that supply chain systems were failing because they lacked adequate architecture to handle the demands of the business environment in which they operate. Because of global sourcing and distribution, manufacturing has become more interdependent, dynamic, and unpredictable. Pharmaceutical supply chains have become more complicated as a result, increasing the number of parties involved and the degree of uncertainty that may be placed on the networks that deliver pharmaceutical goods. Only when it comes to timely delivery and the correct location at the right time is this sector truly relevant. A difficult and competitive business environment has resulted from this reality; pharmaceutical businesses are now looking for operational status that will help them improve their supply chain operations. The impact of SCR (Supply Chain Reliability) in Pakistan's pharmaceutical business is the focus of this article. It is the goal of this study to identify approaches and generate information about the degree of supply chain resilience and the determinants of relational competences of upstream and downstream supply chains, as well as the role of internal integration in making the pharmaceutical supply chain robust.

The research was supported by EPSRC (Award Nos. EP/R023522/1, EP/R023603/1, EP/R023921/1, EP/R023638/1, EP/R008841/1, and EP/V055232/1) and financial support from the UK Catalysis Hub funded by EPSRC Grant reference EP/R027129/1. J.W. and S.C.P. gratefully acknowledge support from the EPSRC (EP/P007821/1) and also thank the U.K. ARCHER HPC facility and the THOMAS HPC (the UK Materials and Molecular Modelling Hub, partially funded by EPSRC EP/P020194) for providing computation resources, via the membership of the UK's HEC Materials Chemistry Consortium (funded by the EPSRC Grant Nos. EP/L000202, EP/709 P007821/1, EP/R029431, and EP/T022213). High‐performance nanoparticle platforms can drive catalysis progress to new horizons, delivering environmental and energy targets. Nanoparticle exsolution offers unprecedented opportunities that are limited by current demanding process conditions. Unraveling new exsolution pathways, particularly at low‐temperatures, represents an important milestone that will enable improved sustainable synthetic route, more control of catalysis microstructure as well as new application opportunities. Herein it is demonstrated that plasma direct exsolution at room temperature represents just such a step change in the synthesis. Moreover, the factors that most affect the exsolution process are identified. It is shown that the surface defects produced initiate exsolution under a brief ion bombardment of an argon low‐pressure and low‐temperature plasma. This results in controlled nanoparticles with diameters ≈19–22 nm with very high number densities thus creating a highly active catalytic material for CO oxidation which rivals traditionally created exsolved samples. Publisher PDF

The disposal of dye-contaminated wastewater is a major concern around the world for which a variety of techniques are used for its treatment. The photocatalytic treatment of dye-contaminated wastewater is one of the treatment methods. Semiconductor-assisted photocatalytic treatment of dye-contaminated wastewater has gained pronounced attention recently. This review outlines the recent advancements in the photocatalytic treatment of dye-contaminated wastewater. The photocatalytic degradation of dyes follows three types of mechanisms: (1) dye sensitization through charge injection, (2) indirect dye degradation through oxidation/reduction, and (3) direct photolysis of dye. Several experimental parameters like initial concentration of dyes, pH, and catalyst dosage significantly affect the photocatalytic degradation of dyes. The photocatalytic materials can be categorized into three generations. The single-component (e.g., ZnO, TiO2) and multiple component semiconductor metal oxides (e.g., ZnO–TiO2, Bi2O3–ZnO) are categorized as first-generation and second-generation photocatalysts, respectively. The photocatalysts dispersed on an inert solid substrate (e.g., Ag–Al2O3, ZnO–C) are classified as third-generation photocatalysts. Finally, we reviewed the challenges that affect the photocatalytic degradation of dyes.

In this study, micellar enhanced ultrafiltration, MEUF, being an active methodology, has been employed to remove Procion Blue MxR (PBM) from synthetic effluent. MEUF is being applied to reduce the toxicity level of aqueous system using the micellar media of cationic surfactants i.e. Cetyl trimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC). Subsequently, the effect of addition of nonionic surfactant, Triton X-100 (TX-100), on solubilizing power of cationic surfactants is investigated. The values of partition coefficient and free energy of partition reflect the extent of interaction of the dye with the surfactants. Initially molecules of pollutants i.e. dye form ion pairs with ionic surfactants and, later on, the same is incorporated within micelle. Maximum value of free energy of partition ΔG

This study reports the fabrication of Fe2O3, Bi2O3, and BiFeO3, characterization and evaluation of the photocatalytic performances for methylene blue dye degradation. The materials were synthesized by precipitation method and characterized by scanning electron microscopy, X-ray diffraction, energy dispersive X-rays analyses, and Fourier transform infrared analyses. The photocatalytic activities of Fe2O3, Bi2O3, and BiFeO3 were compared by performing degradation experiments with 50 mL of 100 mg/L methylene blue solution. The as-prepared BiFeO3 was found as 2.4 times and 1.7 times more effective than Fe2O3 and Bi2O3, with a 79, 47, and 57% catalytic activity, respectively. The degradation of methylene blue over the BiFeO3 catalyst was optimized in terms of pH, catalyst dosage, temperature, and methylene blue concentration. The Eley–Rideal mechanism was proposed to describe the reaction kinetics in terms of the first order and second order kinetics model. Activation energy E (kJ/mol), enthalpy ΔH (kJ/mol), entropy ΔS (J/mol) and free energy ΔG (kJ/mol) were calculated as 20.8, 18.2, 197.5 and −45.3 respectively. The negative value of free energy shows that photodegradation is favored in present conditions.

The current investigation was designed to remove halosulfuron methyl from aqueous media by means of neem seed powder (NSP) in batch modes. Characterizations of NSP were carried out by using EDX, SEM, FTIR, point of zero charge and surface analysis. Optimum operation conditions were scrutinized by studying the influence of different factors like solution pH, dose of NSP, contact time, initial halosulfuron methyl concentration and temperature. Result indicates the dependency of the removal of halosulfuron methyl on solution pH and maximal removal (54%) was achieved in acidic medium (i.e. pH 3.0). To identify the chemical surface of NSP, point of zero charge of NSP was determined and was found to be 6.5 which imply that the surface of NSP is positively charged below pH 6.6 and favored the anionic sorption. Kinetics of halosulfuron methyl were demonstrated well by pseudo second order due to highest R2 (0.99) owing to the nearness between experimental and calculated sorption capacities. Isotherm results imply that Langmuir was found to the principal model to explain the removal of halosulfuron methyl and maximum monolayer sorption capacity was determined to be 200 mg g−1. Thermodynamic parameters like ΔH°, ΔG° and ΔS° were calculated from van’t Hoff plot and were found negative which suggest that removal of halosulfuron methyl is exothermic and spontaneous at low temperature. These outcomes insinuate that neem seed power may be a valuable, inexpensive and ecofriendly biosorbent for the removal of pesticides.

Ring expansion reactions fascinate synthetic chemists owing to their importance in synthesizing biologically active compounds and their efficacy in medicinal chemistry. The present review summarizes a number of synthetic methodologies, including stereoselective and regioselective pathways adopted by scientists, for framing medium- to large-size carbo- and heterocycles involving lactams, lactone, azepine and azulene derivatives via ring expansion of six-membered carbo- and heterocycles that have been reported from 2007–2022. Numerous rearrangement and cycloaddition reactions involving Tiffeneau–Demjanov rearrangement, Aza–Claisen rearrangement, Schmidt rearrangement, Beckmann rearrangement, etc., have been described in this regard.

The gamma ray induced degradation of moxifloxacin in aqueous media has been evaluated. The drug solutions (50 & 100 mg/L) were irradiated to absorbed doses of 0.3, 0.6, 0.9, 1.2, 1.5, 2, 3 and 4 kGy using Cs-137 gamma radiation source. The parameters such as drug initial concentration, oxidant (H2O2) concentration and gamma ray absorbed doses were optimized. The efficiency of Advanced oxidation processes (AOP) was evaluated on the basis of degradation, reduction in chemical oxygen demand (COD) and toxicity reduction of the drug. The maximum degradation of 94.01 and 88.30% was achieved when drug solutions were exposed to gamma irradiation absorbed dose of 4 kGy which enhanced to 100 and 99.06% in the presence of H2O2 (0.5 mL/L) for 50 and 100 mg/L respectively. A significant reduction in COD 72 and 75% for 50 mg/L while 65 and 69% in case of 100 mg/L was noted using gamma and gamma/H2O2 respectively at absorbed dose of 4 kGy. The parameters such as dose constant (k), removal efficiency (G-value), gamma ray absorbed doses required for 50, 90 and 99% degradation (D 0.50, D 0.90 and D 0.99) have been calculated. The radiolytic degradation was monitored by UV–Vis spectrophotometer and HPLC, FT-IR studies were performed to investigate the change in functional groups before and after treatment, while GC-MS analysis was carried out to monitor intermediates/degraded end-products. The FT-IR spectra has shown complete destruction of aromatic rings after radiation treatment but a minor peak appeared at 1216 cm−1 corresponding to CO stretching. The GC-MS study for the drug samples treated with gamma/H2O2 has shown no any significant peak which confirms the complete degradation. The cytotoxicity of treated samples was carried out by hemolytic assay and mutagenicity using Ames test before and after each treatment. The hemolytic test showed 73.92% hemolysis, while gamma/H2O2 treatment reduced the mutagenicity to 74.08 and 65.66% against TA98 and TA100 bacterial strains respectively. The response surface methodology (RSM) was employed to optimize the data. The obtained data elaborate that gamma/H2O2process is promising approach for the remediation of pharmaceutical waste effluent.

Fe3O4 known as magnetite is one of the oxides of iron which plays a major role in various fields of sciences. Fe3O4 was synthesized by precipitation method using NH3.H2O, FeCl2.4H2O and FeCl3.6H2O as precursor materials. For synthesis of 5% Ag-Fe3O4, the green synthetic method was used for immobilization of Ag nanoparticles on Fe3O4 using leaves extract of Calotropis gigantea plant. The synthesized Fe3O4 and 5% Ag-Fe3O4 were employed as catalyst in degradation of methylene blue. The photo catalytic activity of Fe3O4 was remarkably enhanced by doping of Fe3O4 with Ag nanoparticles. Advanced instrumental techniques including XRD, EDX, TGA and SEM were used for characterization of synthesized particles. The immobilization of Ag on Fe3O4 enhanced the photo degradation of methylene blue from 40 to 72% at 40 °C which confirms that 5% Ag-Fe3O4 is an active catalyst for treatment of dye contaminated water. Ag-Fe3O4 exhibited almost same catalytic activity in two successive cycles. Bull. Chem. Soc. Ethiop. 2020, 34(1), 123-134. DOI: https://dx.doi.org/10.4314/bcse.v34i1.11

In this study, we are presenting the effect of three ripening stages of air-dried bitter gourd fruit extracts on phenolic acid composition, antioxidant, antibacterial, and anticancer activities. The results showed mature bitter gourd fruit extract in 100% methanol showing 78% DPPHº scavenging activity. Immature dried fruit extract in 80% and 100% methanol showed promising antibacterial activities, i.e., >18.5 ± 0.21 mm zone-of-inhibition against Staphylococcus aureus, while mature dried fruit extract in 80% methanol showed 18.4 ± 0.17 mm zone-of-inhibition against Escherichia coli. Anticancer activity results of 100% methanol extracts of ripened fruit possess showed 6.72 ± 1.81 and 3.55 ± 0.51 mg/mL IC50 values with HeLa and MDBK cancer cell lines, respectively. The overall results indicate that the immature and ripen fruits of BG could be extracted in pure methanol as an antibacterial and anticancer phytomedicine.

Water pollution is one the fundamental problems that have got the serious concerns of the researchers. Water poluution arises due to a number of reasons including domestic, industrial, agricultural, scinec and technology. The textile industry is the main industry that releases the dyes contaminated wastewater to the environment. A varities of protocols have been attempeted for the removal of dyes from aqueous body. Photocatalysis is one of the effective techniques which offer opportunities to overcome the aqueous pollution caused by rapid industrialization and urbanization. The semiconductor metal oxides used as photocatalysts are capable to provide a sustainable and clean ecosystem due to the tunable physiochemical characteristics of semiconductor metal oxides. Titanium dioxide (TiO2) is one of the metal oxides that can be effectively employed as a photocatalyst in the abatement of aqueous pollution due to organic compounds. The catalytic performance of titanium dioxide depends on several parameters like its crystallinity, surface area, and morphology. Titanium dioxide has shown good performance in the different photocatalytic systems, however, the characteristics like wide band gap and low conductivity limit the photocatalytic performance of titanium dioxide. Various attempts have been made to improve the photocatalytic performance of titanium dioxide. Herein, we summarize the various attempts to improve the photocatalytic performance of titanium dioxide in the abatement of aqueous pollution. The attempts made for the improvement of photocatalytic performance of titanium dioxide include modifications in composition, doping of other metal, and formation of heterojunctions with other metal oxides.

Betti bases are pharmaceutically and synthetically important scaffolds due to their diverse range of biological activities and applications in key synthetic transformations in organic synthesis.This work has been sought to contribute to the development, design, and implementation of an improved green methodology with higher atom economy and lower E-factor values for the synthesis of Betti bases.To realize our objectives, we screened out different catalysts and reaction conditions using one-pot multicomponent modified Mannich reaction/Betti reaction by employing 2-naphthol, benzaldehyde and pyrrolidine as model substrates.The developed methodology afforded functionalized Betti bases in 60-100% yields via FeClA facile synthetic methodology with higher atom economy and lower E-factor values to synthesize Betti bases via FeCl

Visible light induced photo catalytic degradation of dyes is an inviting approach in wastewater treatment techniques. In this study, silver loaded alumina was synthesized by immobilization of Ag nanoparticles on Al2O3 by facile green method with Azadirachta indica leaves extract and characterized by different advanced techniques. The prepared Ag-Al2O3 particles were tested as photo catalyst on degradation of methylene blue under visible irradiation. Ag-Al2O3 showed improved photo catalytic performance on photo degradation of methylene blue. The deposition of Ag enhanced the photo catalytic activity of Al2O3 from 35 to 95% degradation of methylene blue. Effect of various parameters on catalytic activity were investigated. Curve Expert computer program was used for kinetics analyses of the data according to Langmuir–Hinshelwood and Eley–Rideal mechanism. A 100 mg L−1 solution (50 mL) completely degraded in 120 min of reaction duration at 50 °C over 0.1 g of 3% Ag-Al2O3 as catalyst. 0.01, 0.06 and 0.08 min−1 were calculated as average rate constants at 30, 40 and 50 °C respectively. 25.7 kJ mol−1 was calculated as average activation energy.

Synthetic dyes are persistent pollutants with poor biodegradability. The present study is about the degradation of direct Congo red dye in aqueous media using the Co-60 gamma radiation source. The experimental conditions such as gamma-ray absorbed doses, amount of oxidant (H2O2) and pH conditions were evaluated. The λmax of dye solution was noted as 498 nm, and then, decrease in absorbance and reduction in chemical oxygen demand (COD) were examined. The complete colour removal of dye was observed at 5 kGy, while a significant COD removal was observed at 15 kGy gamma-ray absorbed dose in conjunction with oxidant for 50 mg/L concentration. It was found that pH has no influence on degradation efficiency. A possible degradation pathway was proposed. The radiolytic end products were monitored by Fourier transform infrared (FTIR) and gas chromatography coupled with mass spectrometry (GC-MS) to explore the degradation mechanism. It was imperative to study the oxidative degradation pathway to provide directions for potential applicability of advanced oxidation process (AOP) in industrial wastewater treatment.

Functional surfaces have great significance for improving the performance of bio-devices. The selection of appropriate ways to functionalise the surfaces of the polymers used for bio-devices are in great demand. In particular, cyclic olefin copolymer (COC) and cyclic olefin polymers (COP) are emerging substrates for bio-devices and possess superior chemical resistance than other polymeric substrates such as polycarbonate (PC). These polymer substrates often require surface modification to provide the functionality required. Here, we present a means to functionalise the surfaces of these polymers by a corona discharge treatment method. The water contact angle (WCA) of as received PC, COC and COP was found to be around 80°, 96° and 93°, respectively. The WCA of PC, COC and COP is reduced by 40%, 46% and 44%, respectively when treated with corona dose of 95 W min/m2. The WCA of PC, COC and COP was further reduced by increasing the corona dosage. The reduction of WCA is found mainly due to the incorporation of oxygen-related functionalities (such as carboxylic, carbonyl or aldehyde groups) as confirmed by high-resolution X-ray photoelectron spectroscopy (XPS) and Time-of-flight secondary mass spectrometry (ToF-SIMS). The oxygen to carbon (O/C) ratio is clearly increased after the corona treatment confirming the depletion of carbon on the functional surfaces. The functionality of surfaces obtained by corona treatment could be useful in the development of new bio-devices.

In this study, Co3O4and Ag-Co3O4were synthesized by a novel and green method using leaves extract ofHelianthus annuusfrom cobalt nitrate and silver nitrate. The synthesized particles were characterized using X-ray powder diffraction, thermal gravimetric analyses, scanning electron microscopy, particle size analyses and UV-Visible spectroscopy. The photo catalytic activities of synthesized Co3O4and Ag-Co3O4were appraised by degrading methyl orange dye and after 120 minutes of reaction a degradation of 53 and 87% was achieved using 100 mg/L (50 mL) solution of methyl orange and 0.1 g Co3O4and Ag-Co3O4as catalyst respectively. This green synthesis of Ag-Co3O4proves to be an eco-benign, environmental benign, simple and effective approach for degradation of dyes in aqueous medium.