Low-cost Chemicals Research Articles

Synthesis and luminescence study of the rare earth ion (Nd3+) doped Sr3Bi(PO4)3 phosphor

Results of a first investigations on luminescence in Nd[Formula: see text] doped Sr3Bi(PO4)3 are presented. Typical emission is in near infrared (NIR) region consisting of lines attributable to f–f transitions. The excitation also comes from f–f transitions involving higher energy levels, spanning a broad spectral range starting from near ultraviolet (nUV) running through NIR. As much as 5[Formula: see text]mol.% of Nd[Formula: see text] could be doped before concentration quenching of luminescence set in. The quenching was attributed to energy transfer between Nd[Formula: see text] ions taking place through a multipolar mechanism; the critical distance being 21.64[Formula: see text]Å. An easy synthesis method involving low-cost chemicals and favorable luminescence properties makes this phosphor a potential candidate for NIR applications.

Overcoming the performance limitations of hybrid redox flow batteries with modular operation

To help solve the energy trilemma, energy storage technologies must demonstrate low cost and high efficiency to avoid inflating the cost of renewable power. Hybrid redox-flow batteries are a promising multi-hour storage technology, as they use low cost chemicals in an easily recyclable format. However, they suffer from low efficiency at low power output, and require periodic maintenance downtime to remove metal from the anode. Here, we show that a modular system can overcome these challenges with appropriate control. A novel optimisation model for modular operation with periodic maintenance is parametrised from a commercial zinc‑bromine hybrid RFB. Independent module control was predicted to improve operational efficiency, with six modules achieving 73 % compared to the peak efficiency of 80 %. A non-obvious schedule for maintenance was determined algebraically, where energy is transferred from a module due maintenance to one that is fresh. It is found that staggering the strip cycles across several days and performing them when PV and load are roughly in balance in the morning is the optimal timing. The findings are significant as they show that maintenance does not preclude hybrid RFB from firm power provision, and that high efficiency is possible during operation through modular control.

Experimental study on glycerol/aldehyde or ketone binary nanofluids for thermal management

Glycerol is a bio-based low-cost chemical, which has been widely studied in the field of heat conduction because of its wide working temperature range and superior thermopysical. However, high viscosity of glycerol is a prominent problem that limit the application of glycerol. In this work, low viscosity and high thermal conductivity of glycerol nanofluids are prepared under the dual role of nanoparticles, in which nanoparticles work as the nanoadditives enable an enhancement of thermal conductivity and specific heat capacity of nanofluids and the catalyst make a decline of viscosity of nanofluids. The thermal and viscosity properties of the nanofluid were investigated, and the addition of 15% acetylacetone and 2% TiO2 increased the thermal conductivity of the nanofluid to 0.3194 W/m·K, which was 8.12% higher than that of the glycerol. Meanwhile, the viscosity was reduced to 357.4 mPa (30 °C) with 15% acetylacetone and 0.5% TiO2 nanoparticles, which was 47% lower than that of glycerol at the same temperature. Additionally, results of fourier transform infrared spectrometer and proton nuclear magnetic resonance demonstrate that acetal reaction plays an important role in reducing the viscosity of nanofluids, meanwhile, the tests of X-ray diffraction show that nanoparticles can be utilized circularly.

Tunable resistive nature of LaMnO3 / Nd0.7Sr0.3MnO3 interfaces: Role of swift heavy ion irradiation

In the present communication, high crystalline quality LaMnO3/Nd0.7Sr0.3MnO3/SrTiO3 (LMO/NSMO/STO) structures were fabricated using low cost chemical solution deposition (CSD) technique to perform swift heavy ion (SHI) irradiation using 100 MeV O+7 ions. X–ray diffraction (XRD) θ–2θ, XRD φ–scan and XRD ω–scan results show a single phase nature having finite and ion fluence influenced strain state, four–fold lattice symmetry with epitaxial growth and an effective influence of ion fluence on the crystalline granular structure of LMO/NSMO/STO structure. Atomic force microscopy (AFM) images suggest an effect of ion fluence on the surface morphology through the creation of defects and local annealing effect. Zero field cooled (ZFC) protocol based LMO/NSMO interface resistivity suggests that transport nature of the LMO/NSMO interface of all studied LMO/NSMO/STO structures is strongly governed by lattice strain between LMO//NSMO layers and STO substrate, strain across LMO and NSMO manganite layers, crystalline granular structure, grain size, grain boundary density and grain boundary nature of the LMO and NSMO manganite thin layers. ZFC protocol followed by field cooled cooling (FCC) and field cooled warming (FCW) protocols for the realization of LMO/NSMO interface resistivity behaviors have been understood on the bases of freezing and trapping of tiny high temperature high resistive insulating clusters within the coexisting low temperature low resistive metallic phase fraction. Observed LMO/NSMO interface resistivity behaviors have been understood using the percolation model fits to the recorded experimental LMO/NSMO interface resistivity data in addition to irradiation influences. Obtained fitting parameters have been discussed in detail based on their variations with different employed resistivity measurement protocols for all pristine and irradiated LMO/NSMO/STO structures.

Rational Design and Lead Optimisation of Potent Antimalarial Quinazolinediones and Their Cytotoxicity against MCF-7.

Quinazolinedione is one of the most outstanding heterocycles in medicinal chemistry thanks to its wide ranges of biological activities including antimalarial, anticancer, and anti-inflammatory. TCMDC-125133 containing a quinazolinedione pharmacophore displays promising antimalarial activity and low toxicity, as described in the GlaxoSmithKline (GSK) report. Herein, the design and synthesis of novel quinazolinedione derivatives is described on the basis of our previous work on the synthesis of TCMDC-125133, where low-cost chemicals and greener alternatives were used when possible. The initial SAR study focused on the replacement of the valine linker moiety; according to the in silico prediction using SwissADME, concise four-step syntheses toward compounds 4-10 were developed. The in-house synthesized compounds 4-10 were assayed for antimalarial activity against P. falciparum 3D7, and the result revealed that only the compound 2 containing a valine linker was tolerated. Another round of lead optimization focused on the replacement of the m-anisidine moiety in compound 2. A library of 12 derivatives was prepared, and the antimalarial assay showed that potent antimalarial activity could be maintained by replacing the methoxy group in the meta position of the phenyl side chain with a fluorine or chlorine atom (21: IC50 = 36 ± 5 nM, 24: IC50 = 22 ± 5 nM). Further lead optimization is underway to enhance the antimalarial activity of this class of compound. The compounds included in the study possess little to no antiproliferative activity against MCF-7 cells.

Versatile superhydrophobic sponge for separating both emulsions and immiscible oil/water mixtures

Much effort in resource recycling and recovery has been devoted to developing durable materials for separation, but their versatility for emulsions and immiscible oil/water mixtures was far from ideal. In this work, a superhydrophobic sponge (MS-EP-APT) was developed using asphaltene (APT), melamine sponges (MS) and polyethyleneimine (PEI) for demulsification and water-oil mixture separation. These three easily obtained materials came from either oil refinement residue or low cost chemicals. The surface wettability, chemical stability, and mechanical durability of the sponge were analyzed to determine its separation potential. This sponge exhibited great separation efficiency for immiscible oil/water mixtures (> 96.0%), surfactant stabilized water-in-oil (W/O) emulsions (> 96.0%) and anionic surfactant-stabilized oil-in-water (O/W) emulsions (> 98.0%). It demonstrated good reusability and salt tolerance even in seawater. The separation mechanisms were proposed to be related to the hydrophobicity, positive charge, and torturous channels of the sponge. These superior performances make our sponge a strong candidate for green manufacturing and engineering in resource recovery and environmental remediation.

Facile synthesis and characterisation of Mn0.5Zn0.5Fe2O4/Fe2O3 as a novel nanocomposite for studying analytical parameters affecting on photocatalytic degradation of basic fuchsin dye

ABSTRACT Restricted biodegradability, toxicity, and carcinogenicity of basic fuchsin dye are the principal reasons that motivate scientists to find methods to remove it. Photocatalytic degradation technology is simple, environmentally friendly, inexpensive, efficient, and does not yield secondary pollution. Most of the catalysts used to degrade basic fuchsin dye require expensive chemicals to prepare. Therefore, the novelty in our work comes from the utilisation of low-cost chemicals for the facile synthesis of Mn0.5Zn0.5Fe2O4/Fe2O3 nanocomposite using the pechini sol-gel method. The synthesised samples at 300, 600, and 900°C were encoded as F300, F600, and F900, respectively. The XRD confirmed that the average crystallite size of the F300, F600, and F900 samples is 95.08, 122.32, and 160.21 nm, respectively. Hence, as the calcination temperature increases, the crystallite size increases as a result of coagulation that occurs at higher temperatures. The FE-SEM images showed that the F300, F600, and F900 samples consist of spherical, (polyhedral and spherical), and (hexagonal and spherical) shapes with an average diameter of 258.64, 470.12, and 625.32 nm, respectively. This change in morphology at different temperatures is due to the discrepancy in the rate of liberation of organic matter at different temperatures. In the presence of hydrogen peroxide, 0.05 g of the Mn0.5Zn0.5Fe2O4/Fe2O3 nanocomposite degrade 100% of 25 mL of 25 mg/L of basic fuchsin dye at pH = 8 within 25 min. Consequently, the other side of the novelty of our work is the ability of the synthesised nanocomposite to effectively degrade a high concentration of the basic fuchsin dye in a short time.

Facile synthesis and characterization of β-cobalt hydroxide/hydrohausmannite/ramsdellitee/spertiniite and tenorite/cobalt manganese oxide/manganese oxide as novel nanocomposites for efficient photocatalytic degradation of methylene blue dye

In this paper, our research team has synthesized new nanocomposites by simple precipitation/ignition method and using low-cost chemicals. Hence, β-cobalt hydroxide/hydrohausmannite/ramsdellitee/spertiniite and tenorite/cobalt manganese oxide/manganese oxide new nanocomposites were synthesized by precipitation of Mn(II)/Co(II)/Cu(II) solution using sodium hydroxide and ignition of precipitate at 700 °C for 3 hrs, respectively. The synthesized nanocomposites were characterized using different instruments such as energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), nitrogen gas sorption analyzer, and UV–vis spectrophotometer. Energy dispersive X-ray analysis revealed that the nanocomposite formed as a result of precipitation consists of copper, cobalt, manganese, and oxygen where the weight percentages are equal to 31.73, 27.01, 17.26, and 24 %, respectively. Also, the nanocomposite formed as a result of ignition consists of copper, cobalt, manganese, and oxygen where the weight percentages are equal to 31.26, 23.87, 14.56, and 30.31 %, respectively. Transmission electron microscope revealed that the nanocomposites formed as a result of precipitation and ignition consist of polyhedral and spherical shapes with an average diameter of 34.50 and 28.56 nm, respectively. The synthesized nanocomposites were used as new photocatalysts for the efficient degradation of methylene blue dye. 0.05 g of the synthesized nanocomposites degrade 100 % of 50 mL of 15 mg/L of methylene blue dye solution within 25 min in the presence of H2O2 under UV light.

Porous Silicon Nano-Quill Anodes for Lithium-Ion Batteries

The growing population and increasing demands for energy are overwhelming our supply of fossil fuels and limiting the availability for future generations. Technologies for energy storage devices are emerging to replace conventional fuel-based technologies to meet emissions goals set by world governments and the rapid electrification of the transportation sector. Lithium-ion batteries (LIBs) are widely used for energy storage in devices across many commercial applications. LIB electrodes are continuously evolving due to demands for higher energy density and long cycling life. Among the recent developments in anode electrode materials, silicon (Si) is regarded as the most promising replacement for graphite due to its high theoretical specific capacity (~4200 mAh g-1), which is over 10 times greater than that of conventional graphite anodes (~372 mAh g-1). Despite the advancements, persisting challenges hinder the commercialization of Si for LIB anodes. Si-based electrodes are susceptible to rapid degradation due to the large volume change (approx. 400%) of Si particles during lithium insertion and extraction. The repeated volume change leads to the pulverization of the Si material, ultimately leading to decreased cycling stability from the loss of contact with the current collector. To overcome this obstacle, 3-dimensional porous and hollow nanostructures have been employed to provide sufficient void space to accommodate the volume change during electrochemical cycling. However, with the demands for material cost-reduction from industry, Si structures' strategic engineering must be cost-effective for commercial viability.Our team has developed a patent-pending cost-effective, scalable, and green methodology to use bio-renewable templates to synthesize a 3-dimensional Si architecture, called Si nano-quills (SiNQs). We innovated a two-step, cost-effective process that yields SiNQs with a porous morphology and hollow interior structure. First, in a scalable sol-gel process, silica gel particles were prepared using commonly available low-cost chemicals. The unique mesoporous SiNQ morphology was engineered using surfactant-modified cellulose nanocrystals as a bio-renewable sacrificial template. The templates were removed via thermal treatment to form silica nanoparticles. These particles, called silica nano-quills (SilicaNQs), possess a 3-dimensional bulk structure comprised of hollow quill-like arms and a high degree of porosity. In the second step, we employed a low-temperature magnesiothermic reduction method to convert SilicaNQs into SiNQs with a relatively large surface area. Anode electrodes were fabricated using SiNQs as the active material for electrochemical testing. The slurry was prepared using the active material, carbon black, and PVDF with a mass ratio of 60:20:20 coated onto an ion-permeable Bucky Paper (BP, a flexible and conductive paper made of carbon nanotubes). The 2032-type coin cells were assembled for battery testing using SiNQ electrodes (with an active mass loading of 1 mg cm-2) and a lithium metal chip as the counter electrode. The coin cells were cycled at a current rate of 0.1C (420 mA g-1) over the potential range of 0.01 – 1.0 V at room temperature. The SiNQ anode offered superior battery capacity retention of 73% of the initial reversible capacity of 963 mAh g-1 after 220 cycles. In comparison, batteries fabricated from the Mg reduction of commercially available mesoporous silica, SBA-15, offer capacity retention of only 52.6% after 100 cycles. The SiNQ precursor is engineered to possess porous walls with a superior BET surface area (1265 m2 g-1) compared to SBA-15 (550 m2 g-1). After Mg reduction, the SiNQs retain a BET surface area of 232 m2 g-1, whereas the surface area of reduced SBA-15 is 74 m2 g-1. The superior performance of SiNQs is due to their unique morphology that offers high surface area and porosity for effective diffusion of lithium ions and more sites for interactions with lithium ions, leading to a higher reversible capacity. Moreover, the porous architecture of SiNQs can effectively mitigate the volume change issue during lithiation and delithiation processes, thus providing a good cycling performance.

Magnetic cellulose nanocrystals as efficient support for indium(III) in the synthesis of tetrazoles and phthalazines

Catalysts, especially heterogeneous catalysts, play an essential role in organic transformation reactions. Hence, we use a composite of cellulose nanocrystals (CNC) and Fe3O4 NPs as new support for indium(III) and evaluate the performance of fabricated Fe3O4/CNC-In(III) catalyst in the synthesis of two different heterocyclic compounds: Tetrazole and phthalazine derivatives. Although metal oxides and metal NPs are in the spotlight due to their excellent catalytic activity, they are limited in application due to their self-agglomeration in the reaction mixture, resulting in reduced performance. The addition of CNC to Fe3O4 NPs due to rich-hydroxyl sites on the CNC surface and its interaction turns Fe3O4/CNC into a stable and appropriate substrate for the immobilization of indium(III). The formation and physicochemical properties of the catalyst were endorsed by FT-IR, SEM, TEM, EDS, XRD, TGA, and elemental mapping analysis. In addition, the synthesis of substituted 2-(1H-tetrazole-5-yl) acrylonitrile and 2H-indazolo[2,1-b]phthalazinetriones was performed under solvent-free conditions; this feature is another advantage of the current procedure. Utilization of sustainable natural materials and low-cost chemicals, short reaction time, high catalytic activity, magnetic feature and easy separation with external magnet, excellent reusability without showing substantial activity loss for six runs, and uniform distribution are some of the significant advantages of this catalyst.

Investigations on interface charge conduction mechanisms for chemically grown manganite – Manganite structure: Hysteretic current – Voltage characteristics

In the present study, high quality LaMnO3–δ/La0·7Ca0·3MnO3/LaAlO3 (LMO/LCMO/LAO) manganite – manganite structure was successfully prepared using low cost chemical solution deposition (CSD) method. Temperature dependent resistive switching (RS) was performed across the manganite – manganite structure and various electronic processes have been employed to understand observed RS behavior. Various theoretical models have been used to understand the charge conduction involved in the hysteretic current – voltage (I–V) characteristics at different temperatures. Charge carrier conduction processes have been investigated for separate I–V cycles of RS characteristics where thermionic emission and space charge limited conduction mechanisms have been identified as appropriate charge carrier conduction mechanisms. Temperature dependent barrier height and other obtained fitting parameters have been discussed in detail.

Facile preparation of melamine foam with superhydrophobic performance and its system integration with prototype equipment for the clean-up of oil spills on water surface

A simple and efficient method was developed to rectify the surface properties of commercial melamine foam. The process was based on the siloxane coating originated from the silanization of methyltrimethoxysilane and tetraethoxysilane. The foam can be easily scaled up by employing low-cost chemicals and devices. The studies on the properties of the material showed that the wettability of melamine foam was changed to superhydrophobic with a water contact angle of 156° due to the presence of alkylsilane. The modified foam exhibited excellent oil/water selectivity and high oil absorption capacities of 77–163 times its own weight. The retention of absorption capacity was greater than 97% after 5000 cycles compression. These fascinating characteristics made the modified foam exceptional recyclability for commonly organic solvents and oils without obvious dissolution/swelling. Based on these inspiring results, the material can be employed for the continuous separation of various oil compounds floating on water surface with the assistance of a vacuum pump. Moreover, the prepared material was integrated with an apparatus to develop a prototype oil collector for the remediation of oil spills in a larger open-air environment. The devices could be readily used in a range of real-world applications, including industrial oil spill clean-up.

Electric Field Effects on Charge Conduction for LaMnO3 Controlled La0.7Ca0.3MnO3 Manganite

Control over the different electronic states in mixed valent manganites advances the development of oxide based electronic devices. In this context, carrier density is one of the key aspects that controls the electronic ground states of manganites in a sparkling way since it does not create any impurity within the manganite lattice, unlike chemical doping process. LaMnO3–δ / La0.7Ca0.3MnO3 / LaAlO3 (LMO / LCMO / LAO) manganite based heterostructure was fabricated by low cost chemical solution deposition (CSD) method where thickness of LMO ∼ 50 nm and LCMO ∼ 100 nm were grown on (100) single crystalline substrate. Structural quality and epitaxial nature of heterostructure was verified by performing X–ray diffraction (XRD) ϕ–scan measurement on grown La0.7Ca0.3MnO3 / LaAlO3 (LCMO / LAO) 100 nm thin film and LMO / LCMO / LAO heterostructure. Understanding of few other structural, morphological and chemical aspects of presently studied LMO / LCMO interface and LMO / LCMO / LAO heterostructure has been presented through grazing incidence X–ray diffraction (GIXRD), Rocking curve XRD, cross sectional scanning electron microscopy (SEM), atomic force microscopy (AFM) and X–ray photoelectron spectroscopy (XPS) measurements. Electric field modulated charge conduction for LCMO manganite channel has been understood in the context of field effect configuration (FEC) based transport measurements where temperature dependent LCMO channel resistance was recorded under different control electric fields applied across LMO / LCMO interface in LMO / LCMO / LAO heterostructure. Thermal hysteretic resistance measurements for LCMO manganite channel under zero control electric field exhibit metal to insulator phase transition at TP with finite width of the hysteretic resistance behaviours between two thermal cycles, i.e. cooling and heating. This has been understood on the basis of phase separation scenario, freezing effect and non–reversible electronic phase transformation. Applied control electric field induced improvement in resistance of LCMO manganite channel and reduction in value of TP have been understood on the basis of charge injection process, strain induced disorder dependent charge conduction, phase separation based movements of metal–insulator interface and negligibly small Joule heating effect. Realization of insulating phase fraction, arrested during thermal cycles, has been discussed for the explanation of reduced width of the hysteretic resistance behaviours of LCMO channel upon increase in control electric field applied across LMO / LCMO interface. Possible charge conduction mechanisms have been understood on the basis of Zener double exchange (ZDE) polynomial law for obtained metallic state of LCMO channel. Variation in electroresistance (ER) of LCMO manganite channel with temperature under different control electric fields (applied across LMO / LCMO interface) has been discussed on the basis of charge injection process with an effective role of phase separation scenario of LCMO channel in LMO / LCMO / LAO heterostructure.

Electrical Conductivity and Compressive Strength of Cement Paste with Multiwalled Carbon Nanotubes and Graphene Nanoplatelets

Many studies have been conducted using carbon-based nanomaterials (CBNs) for improving the electrical conductivity and mechanical properties of cementitious composites, but their practical use is yet to be achieved. Several methods have been attempted to secure the dispersibility in the cementitious composite matrix of CBNs, such as multiwalled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs). In this study, MWCNTs and GNPs were noncovalently functionalized using melamine, a low-cost chemical, and ball milling, a simple process commonly used in industrial fields. Additionally, MWCNTs and GNPs having one- and two-dimensional shapes were mixed with the cement paste to examine their effect on electrical conductivity and compressive strength. Following the experiment, it was shown that the electrical conductivity was improved via the noncovalent functionalization of MWCNT and GNP. The compressive strength increased up to approximately 0.30–0.60% of the CBNs content; however, for CBN content higher than 0.60%, the compressive strength decreased. The hybrid MWCNT and GNP mixture had a negligible effect on the electrical conductivity and compressive strength.

Thiourea and hydrogen peroxide priming improved K+ retention and source-sink relationship for mitigating salt stress in rice

Plant bioregulators (PBRs) represent low-cost chemicals for boosting plant defense, especially under stress conditions. In the present study, redox based PBRs such as thiourea (TU; a non-physiological thiol-based ROS scavenger) and hydrogen peroxide (H2O2; a prevalent biological ROS) were assessed for their ability to mitigate NaCl stress in rice variety IR 64. Despite their contrasting redox chemistry, TU or H2O2 supplementation under NaCl [NaCl + TU (NT) or NaCl + H2O2 (NH)] generated a reducing redox environment in planta, which improved the plant growth compared with those of NaCl alone treatment. This was concomitant with better K+ retention and upregulated expression of NaCl defense related genes including HAK21, LEA1, TSPO and EN20 in both NT and NH treated seedlings. Under field conditions, foliar applications of TU and H2O2, at vegetative growth, pre-flowering and grain filling stages, increased growth and yield attributes under both control and NaCl stress conditions. Principal component analysis revealed glutathione reductase dependent reduced ROS accumulation in source (flag leaves) and sucrose synthase mediated sucrose catabolism in sink (developing inflorescence), as the key variables associated with NT and NH mediated effects, respectively. In addition, photosystem-II efficiency, K+ retention and source-sink relationship were also improved in TU and H2O2 treated plants. Taken together, our study highlights that reducing redox environment acts as a central regulator of plant’s tolerance responses to salt stress. In addition, TU and H2O2 are proposed as potential redox-based PBRs for boosting rice productivity under the realistic field conditions.

Experimental Studies on Demulsification of Heavy Crude Oil-in-Water Emulsions by Chemicals, Heating, and Centrifuging

Summary The development of concentrated and highly stable oil-in-water (O/W) emulsion is considered to be a cost-effective alternative for the transportation of produced heavy crude oils. However, the demulsification of a transported O/W emulsion is necessary once it reaches the destination. This article experimentally investigates the performance of four low-cost chemicals of varying water solubility as potential demulsifiers, independently and in combinations, for demulsifying two Indian heavy crude O/W emulsions prepared for pipeline transportation. The chemical demulsifiers used, in order of their higher water solubility, are: polyethylene glycol 400 (PEG) > polyoxyethylene (20) sorbitan monooleate (Tween-80) > linear alkylbenzene sulfonic acid (LABSA) > n-octylamine (OA). For this study, stable O/W emulsions (in the 60:40 ratio) of two Indian heavy crude oils were prepared using high-frequency ultrasonic waves in the presence of Triton X-100 as a surfactant. Both crude oils were characterized at first based on their physicochemical properties, infrared (IR) spectrum, and rheological properties. Prepared O/W emulsions were characterized based on rheological properties and droplet size. A bottle test method with heating (using a water bath) and enhanced gravity (by centrifuge) has been used to study the demulsification efficiency of used chemicals. Complete demulsification of both emulsions was achieved as desired. The synergetic effect of the interaction between two suitable demulsifiers provided remarkably better performance than that of independent returns, leading to minimization of the amount of demulsifier and the energy requirement for complete demulsification of both emulsions.

One-Step Hot Microembossing for Fabrication of Paper-Based Microfluidic Chips in 10 Seconds.

In recent years, microfluidic paper-based analytical devices (µPADs) have been developed because they are simple, inexpensive and power-free for low-cost chemical, biological and environmental detection. Moreover, paper is lightweight; easy to stack, store and transport; biodegradable; biocompatible; good for colorimetric tests; flammable for easy disposal of used paper-based diagnostic devices by incineration; and can be chemically modified. Different methods have been demonstrated to fabricate µPADs such as solid wax printing, craft cutting, photolithography, etc. In this study, one-step hot microembossing was proposed and demonstrated to fabricate µPADs. The processing parameters like embossing temperature, pressure and time were systematically investigated. It was found that, at 55 °C embossing temperature, the embossing pressure ranging from 10 to 14 MPa could be applied and the embossing time was only 5 s. This led to the overall processing time for fabrication of µPADs within 10 s. Glucose detection was conducted using the µPADs as fabricated, and a linear relationship was obtained between 5 and 50 mM.

Development of C3 symmetric triaminoguanidine-2-naphthol conjugate: Aggregation induced emission, colorimetric and turn-off fluorimetric detection of Co2+ ion, smartphone and real sample applications

Herein, a simple aggregation induced emissive star shaped organic compound LH3 with 2-naphthol moiety was prepared by simple one-pot condensation reaction from low-cost chemicals. Aggregation induced emission (AIE) features of LH3 was established in DMF-H2O mixtures. Further, the cation sensing capability of the probe LH3 was examined towards various metal ions in DMF-H2O (Tris−HCl buffer solution pH 7.4, 8:2, and v/v) by using UV–vis and emission spectral experiments. The probe LH3 exhibits high selective and sensitive detection towards Co2+ ions over different metal ions via colorimetric as well as turn-off fluorometric fashion. Job’s plot analysis and mass spectral measurement confirms the formation of LH3-Co2+ complex (L-Co3) with 1:3 stoichiometric ratio. When the probe LH3 binds with Co2+ in 1:3 ratio, turn-off emission behavior was observed via chelation enhanced quenching (CHEQ) mechanism. To establish the practical application of the probe LH3, the detection of Co2+ ions present in real water was established. The visual noticeable color variation of probe LH3 upon addition of Co2+ ions have been clearly incorporated with a smartphone app via variation in RGB color values to build an on-site analysis of Co2+ ions.

Efficient and recyclable palladium enriched magnetic nanocatalyst for reduction of toxic environmental pollutants

In this paper, highly stable, powerful, and recyclable magnetic nanoparticles tethered N-heterocyclic carbene-palladium(II) ((CH3)3-NHC-Pd@Fe3O4) as magnetic nanocatalyst was successfully synthesized from a simplistic multistep synthesis under aerobic conditions through easily available low-cost chemicals. Newly synthesized (CH3)3-NHC-Pd@Fe3O4 magnetic nanocatalyst was characterized from various analytical tools and catalytic potential of the (CH3)3-NHC-Pd@Fe3O4 magnetic nanocatalyst was studied for the catalytic reduction of toxic 4-nitrophenol (4-NP), hexavalent chromium (Cr(VI)), Methylene Blue (MB) and Methyl Orange (MO) at room temperature in aqueous media. UV-Visible spectroscopy was employed to monitor the reduction reactions. New (CH3)3-NHC-Pd@Fe3O4 magnetic nanocatalyst exhibited excellent catalytic activity for the reduction of toxic environmental pollutants. Moreover, (CH3)3-NHC-Pd@Fe3O4 magnetic nanocatalyst could be easily and rapidly separated from the reaction mixture with the help of an external magnet and recycled minimum five times in reduction of 4-NP, MB, MO and four times in Cr(VI) without significant loss of catalytic potential and remains stable even after reuse.

Vesicle-Templated Polymerization, a Review

Vesicle-templated polymerization has developed into a mature research area over the last 35 years. The main purpose of this approach was to produce hollow polymeric nanocapsules from low-cost chemicals, utilizing a simple emulsion-polymerization-like process. Over the years, understanding of the different varieties of the approach has grown. In retrospect, the characterization methods utilized to determine the morphologies are essential to draw the right conclusions. In this Review, first, an overview of the earlier attempts to produce nanocapsules with uniformous wall thickness will be given, looking at the results with the current understandings, greatly enhanced by quantification of the different morphologies through cryo-TEM images. The latest approach, reactive oligomer assisted transcriptive synthesis, seems to be able to fulfill the initial purpose and almost 100% of nanocapsule morphologies can be formed under the right conditions.