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In recent years, the continuously increasing demand for wastewater treatment has increased research on perovskite-based materials with narrow band gaps.

Polymer dielectric possess advantages of mechanical flexibility, low temperature processing, and cost. However, for practical applications dielectric constant of polymers is not high enough. To raise the dielectric constant, polymers are often composited with fillers of various morphologies (one-dimensional, two-dimensional, three-dimensional) and types (inorganic, organic, carbon, conductive, non-conductive). Recently discovered two-dimensional (2D) materials including graphene, transition metal dichalcogenides, MXenes, ferroelectric ceramics, etc. have been discovered. These materials have excellent electrical, mechanical, thermal properties and high specific surface area, which makes these ideal materials to reinforce the properties of polymers, especially dielectric properties. Here, in this review we summarize the latest developments regarding the use of 2D fillers to improve the dielectric properties of polymer composites. We have systematically discussed synthesis of 2D materials, processing of their 2D filler/polymer composites, theoretical background of dielectric properties of these composites, and literature summary of the dielectric properties of polymer composites with various type of 2D fillers.

Mixed matrix membranes (MMMs) of cellulose acetate/poly(vinylpyrrolidone) (CA/PVP) infused with acid functionalized multiwall carbon nanotubes (f-MWCNTs) were fabricated by an immersion phase separation technique for hemodialysis application. Membranes were characterized using FTIR, water uptake, contact angle, TGA, DMA and SEM analysis. The FTIR was used to confirm the bonding interaction between CA/PVP membrane matrix and f-MWCNTs. Upon addition of f-MWCNTs, TGA thermograms and glass transition temperature indicated improved thermal stability of MMMs. The surface morphological analysis demonstrated revealed uniform distribution of f-MWCNTs and asymmetric membrane structure. The water uptake and contact angle confirmed that hydrophilicity was increased after incorporation of f-MWCNTs. The membranes demonstrated enhancement in water permeate flux, bovine serum albumin (BSA) rejection with the infusion of f-MWCNTs; whereas BSA based anti-fouling analysis using flux recovery ratio test shown up to 8.4% improvement. The urea and creatinine clearance performance of MMMs were evaluated by dialysis experiment. It has been found that f-MWCNTs integrated membranes demonstrated the higher urea and creatinine clearance with increase of 12.6% and 10.5% in comparison to the neat CA/PVP membrane. Thus, the prepared CA/PVP membranes embedded with f-MWCNTs can be employed for wide range of dialysis applications.

Wearable sensors are the technology of the future and will become an integral part of daily life. These sensors can monitor the physical activities and biochemical information of an individual, organ functions, and environmental changes. A wearable sensor may comprise a sensing element, electrodes, substrate, power unit and data processing unit. Selectivity, sensitivity and reliability of a wearable sensor depend on the sensing element, electrodes and substrate, which can be designed/fabricated with a suitable material. A variety of materials including carbon materials, conductive polymers, metal oxides, metals, elastomers, and nanomaterials have been used depending on the applications of the sensor. In this review, we will summarize the recent developments regarding the use of advanced materials for applications in wearable sensor technologies.

Herein, an attempt has been made to investigate effect of C and Mn partitioning during quenching and partitioning heat-treatment process on microstructure, mechanical, and electrochemical properties of experimental 3 wt% Mn steel. The quenching and partitioning heat-treatment process was applied to the experimental steel with varying partitioning time periods ranging from 15 to 120 s at a constant partitioning temperature of 425 °C. The partitioning time period of 15 s resulted in a high volume fraction of supersaturated lath martensite with a small volume fraction of retained austenite. With increasing partitioning time period to 45–60 s, diffusion of C and Mn from martensite to retained austenite occurred resulting in the formation of decreased volume fraction of martensite phase with a reduced carbon and increased volume fraction of retained austenite phase with increased carbon. Partitioning for 90 s produced a moderate volume fraction of both lath martensite and retained austenite phases with nucleation of secondary phase, epsilon carbides. This phase transformation provided an optimum combination of 21% improved Vickers hardness and threefold improved impact toughness compared to as-received steel. Electrochemical properties of quenched and partitioned 3 wt% Mn steel were also evaluated in a 3 wt% NaCl solution. The highest corrosion resistance was achieved after prolonged partitioning of 120 s, whereas slightly low corrosion resistance was achieved after partitioning of 90 s.

Chitosan was grafted with polyorthoethylaniline through oxidative polymerization using ammonium persulfate as oxidant, resulting in the formation of a biocomposite of chitosan-grafted-polyorthoethylaniline (CH-g-POEA). The synthesized biocomposite (CH-g-POEA) was characterized by FTIR, SEM, and TGA. Adsorption of methyl orange (MO) dye by CH-g-POEA was studied, wherein the Langmuir isotherm model with a R2 of 0.9979 and adsorption capacity of 45.7 mg/g was evaluated.

With the increasing pressure of population, the energy demand is growing explosively. By 2050, it is expected that the world population may reach to about 9 billion which may result in the increase of energy requirement to about 12.5 trillion watts. Due to increasing pressures of population, industries and technology, concerns to find possibilities to cope with increasing demand of energy resources, arise. Although the renewable energy resources including fossil fuels, wind, water and solar energy have been used for a long time to fulfill the energy requirements, but they need efficient conversions and storage techniques and are responsible for causing environmental pollution due to greenhouse gases as well. It is thus noteworthy to develop methods for the generation and storage of renewable energy devices that can replace the conventional energy resources to meet the requirement of energy consumption. Due to high energy demands, the sustainable energy storage devices have remained the subject of interest for scientists in the history, however, the traditional methods are not efficient enough to fulfill the energy requirements. In the present era, among other variety of advanced treatments, nano-sciences have attracted the attention of the scientists. While talking about nano-science, one cannot move on without admiring the extraordinary features of carbon nanotubes (CNTs) and other carbon based materials. CNTs are on the cutting edge of nano science research and finding enormous applications in energy storage devices. Excellent adsorption capabilities, high surface area, better electrical conductivity, high mechanical strength, corrosion resistance, high aspect ratio and good chemical and physical properties of CNTs have grabbed tremendous attention worldwide. Their charge transfer properties make them favorable for energy conversion applications. The limitation to the laboratory research on CNTs for energy storage techniques due to low specific capacitance and limited electrochemical performance can be overcome by surface functionalization using surface functional groups that can enhance their electrical and dispersion properties. In this chapter, ways CNTs employed to boost the abilities of the existing material used to store and transfer of energy have been discussed critically. Moreover, how anisotropic properties of CNTs play important role in increasing the energy storage capabilities of functional materials. It will also be discussed how various kinds of materials can be combined along CNTs to get better results.

Management of coal fly ash as a particulate byproduct of coal burning has become an issue to be solved right away due to environmental concerns related to soil, water, and air pollution. Many attempts have been made by researchers for the conversion of coal fly ash into useful products while searching feasible avenues for its sustainable utilization. Wastewater remediation using coal fly ash is one such attempt solving both waste management and water quality issues. The characteristics like morphology, surface area, porosity, and chemical composition (silica, alumina, iron oxide, titania, etc.) make coal fly ash amenable material for potential application in wastewater treatment. Few reports have summarized the coal fly ash utilization in wastewater treatment but solely discussed the adsorption. Besides adsorption, the current paper aims to highlight the possibilities of using coal fly ash in wastewater treatment by different technologies that extend the utilization scope in the domains of filtration, Fenton process, photocatalysis, and coagulation. The promising use of coal fly ash as an adsorbent, membrane filter, Fenton catalyst, photocatalyst, and as an integral part of these structures is reviewed. Finally, the current trends and future prospects on utilization modes of coal fly ash in wastewater treatment are stated.

Ultra deep desulfurization of liquid fuels such as gasoline/diesel has attracted considerable attention of modern clean fuel research due to strict environmental regulations. Apart from that, SOx produced during combustion, poison the catalytic converter and exhaust emission system. Comparing to conventional catalytic and hydrodesulfurization techniques, adsorptive method for removal of sulfur bearing compounds e.g. thiophene derivatives is a promising approach which does not require hydrogen gas and high temperature. In this study, we used nickel sulfide nanoparticles incorporated poly(methyl methacrylate)-zirconia membranes as potential affinity material for adsorptive extraction of dibenzothiophene from n-hexane. The functionality and surface morphology of synthesized material was examined by Fourier transformation infrared (FTIR) spectroscopy and atomic force microscopy (AFM) images, respectively. The quantitative data regarding adsorptive removal of dibenzothiophene was determined by monitoring the shift in absorbance values of standard solutions before and after treating with synthesized material under ambient conditions. Nickel sulphide nanoparticles exhibited suitable rebinding response for removal of dibenzothiophene down to 1 ppm due to affinity interactions which is useful concerning ultra deep desulfurization. Finally, nickel sulphide nanoparticles were incorporated in poly(methyl methacrylate)-zirconia membrane which showed potential application for adsorptive desulfurization of dibenzothiophene at ambient conditions.

Sitagliptin is a hypoglycaemic agent used to reduce blood sugar levels in patients with type 2 diabetes mellitus (T2DM). Real time monitoring of sitagliptin levels is crucial to prevent overdose, which might cause liver, kidney and pancreatic diseases. As an alternative solution, a sitagliptin voltammetric sensor was fabricated using artificial receptors called electroactive molecularly imprinted polymer nanoparticles (nanoMIPs). The nanoMIP tagged with a redox probe (ferrocene) combines both the recognition and reporting functions. Traditional electrochemical sensors determine the redox activity of an analyte. Thus, they are influenced by interfering molecules and the nature of the sample. These innovative nanoMIPs allow us to easily design and customise sensors, increase their sensitivity and minimise the cross reactivity in biological samples. The present technology replaces the traditional enzyme–mediator pairs used in traditional biosensors. The polymer composition was optimized “in silico” using docking and screening methods. Nanoparticles were synthesized via free radical polymerization and a solid phase method and then characterized by infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and dynamic light scattering (DLS). The specific sitagliptin nanoparticles were covalently immobilized on platinum electrodes via silane and carbodiimide chemistry. The determination of sitagliptin in human plasma by a nanoMIP sensor was assessed by differential pulse voltammetry (DPV). The sensor current response was directly related to the change in nanoMIP conformation triggered by the analyte. The optimisation of the sensor response was made by adjusting (i) the silane concentration, (ii) nanoMIP concentration, and (iii) immobilization time. The sensor measurements in plasma revealed high selectivity and a sensitivity of 32.5 ± 0.6 nA pM−1 towards sitagliptin, and the limit of detection of the fabricated sensor was found to be 0.06 pM. The sensor displayed a satisfactory performance for the determination of sitagliptin in spiked human plasma, demonstrating the potential of this technology for drug monitoring and clinical diagnosis.

Chitosan and polyethylene glycol (PEG-600) membranes were synthesized and crosslinked with 3-aminopropyltriethoxysilane (APTES). The main purpose of this research work is to synthesize RO membranes which can be used to provide desalinated water for drinking, industrial and agricultural purposes. Hydrogen bonding between chitosan and PEG was confirmed by displacement of the hydroxyl absorption peak at 3237 cm−1 in pure chitosan to lower values in crosslinked membranes by using FTIR. Dynamic mechanical analysis revealed that PEG lowers Tg of the modified membranes vs. pure chitosan from 128.5 °C in control to 120 °C in CS-PEG5. SEM results highlighted porous and anisotropic structure of crosslinked membranes. As the amount of PEG was increased, hydrophilicity of membranes was increased and water absorption increased up to a maximum of 67.34%. Permeation data showed that flux and salt rejection value of the modified membranes was increased up to a maximum of 80% and 40.4%, respectively. Modified films have antibacterial properties against Escherichia coli as compared to control membranes.

Industrial effluent (from textile, fertilizer, paper industries, pharmaceuticals, soap, etc.) usually contains a wide variety of pollutants such as dyes, pesticides, surfactants, oil and grease, antibiotics, various metal ions, auxiliary chemicals, etc. The release of poisonous pollutants is extremely destructive to aquatic life. Hence, the wastewater contaminants need to be effectively treated and removed before being discharged into water bodies. Sustainable environmental remediation is currently one of the main global challenges. Heterogeneous photocatalysis plays a significant role in wastewater treatment. Photocatalytic semiconductor materials such as metal oxides (alone as well as binary/ternary nanocomposites) are being used efficiently for the degradation/removal of harmful organic pollutants from wastewater. In this chapter, recent studies related to wastewater treatment using metal oxides and their ternary nanocomposites have been presented. The main focus is on the versatility and combination of various semiconductor materials to get ternary arrangements, which are useful to increase the visible light response of photocatalysts as well as to avoid recombination of light-induced electrons and holes. The ternary metal oxide nanocomposites are considered as advanced photocatalytic materials for degradation of detrimental pollutants. Additionally, it is reported that the rational design of ternary nanocomposites shows the interaction between different metal oxides and helps in water remediation applications.

s Nanotechnology is an inspiring discipline with numerous cost-effective and novel applications. Nowadays, nanotechnology is being empowered in the field of medicine, agriculture, space science, food processing, etc. The superior behavior of nanomaterials over large particles results in their high and effective utilization. Therefore, the development of new nanomaterials with multidimensional applications is the current need of the scenario. Among various nanoparticles, the metal ferrite nanoparticles (MFNPs) emerged as an advanced class of magnetic nanomaterials owing to their fascinating physicochemical properties. These nanoparticles possess a wide range of applications in environmental remediation. The MFNPs due to their large surface area, high stability, facile synthesis strategies, and magnetic characteristics have been studied extensively for the water purification system. Additionally, decorating the MFNPS with silver nanoparticles (AgNPs) not only improves their photocatalytic degradation ability but also imparts antibacterial performance. This chapter holds the important characteristics of silver-doped metal ferrites nanoparticles (Ag-MFNPs) in wastewater treatment. The role of silver in properties enhancement of MFNPs, their synthesis method with reaction mechanism, and application in photocatalytic degradation and antibacterial activity have been presented.

In this study, volatile composition of leaves of Chorisia speciosa was studied first time. The oil was extracted by microwave-assisted oil extraction and constituents were separated and characterized by gas chromatography - mass spectrometry. A yield of 0.21% was obtained and a total of 25 constituents were identified. Most dominating constituents were: caryophyllene (32.26 %), bicyclogermacrene (9.88 %), humulene (9.26 %), α-selinene (9.18 %) and β-elemene (8.06 %). The anti-bacterial activity of volatile oil was also evaluated against four pathogenic strains. The oil showed different zones of inhibition against different microbes where strongest activity was found against S. aureus (25 mm), moderate activity (15 mm) against E. coli and no activity against S. typhi (9 mm) at the dose value of 3.64 mg. The observed antibacterial activity was due to the presence of various biologically active major and minor constituents.

Environmental remediation using hybrid nanomaterials (HNMs) has been highly acknowledged due to the synergistic effect of binary, ternary, support-based, and/or polymer-based moieties with those of nanomaterials. The fascinating properties of these HNMs such as a large surface area for adsorption, enhanced photocatalysis, tunable size, easy separation, low leaching, requirement of small amounts, reusability, etc., make them excellent candidates for wastewater treatment. These properties of HNMs ensure that the materials are environmentally friendly and efficient. In this chapter, the focus has been devoted to the synthesis (and application in wastewater) of HNMs and the factors that effect the properties of these HNMs. The photocatalytic behavior of different binary, ternary, etc., component HMNs has been described with the methods to provide improved visible light absorption behavior. Various synthesis approaches for HNMs have also been described briefly. Beside this, the use of potential supports such as fly ash and graphene with their photoactive hybrid nanocomposites, polymer-based nanomaterials, and nanomembranes in wastewater treatment has been described. The study proved that these nanocomposites play vital roles in lowering band-gap energies as compared to bare nanomaterials. Hence, it can be concluded that these emerging HNMs, due to their multifunctional properties, are potential materials to be used for wastewater remediation.

Deep frying with repeated use of same edible oil leads to the formation of lipid oxidation products. The presence of these oxidized products formed during frying at elevated temperature is hazardous for human health and therefore, requires prompt analysis for ensuring its fitness/quality. In this study, oxidative degradation of thermally stressed edible oils canola, sunflower and palm olein shortening was studied at 180&#176C ± 5&#176C up to 48 hours. Palm olein shortening remained stable during this period as the increase in its acid value was significantly less than canola and sunflower seed oils. The shortening samples were further studied by attenuated total reflectance Fourier transformation infrared (ATR-FTIR) and gas chromatography mass spectrometry (GC-MS) to evaluate the formation of various oxidation products due to thermal stress. ATR-FTIR indicates the formation of free fatty acids (FFAs), aldehyde groups and change in degree of unsaturation while GC-MS gives important information about profile of FFAs. The combination of these analytical techniques is useful for rapid and highly sensitive analysis of oxidized edible oil thus, ensuring its quality and fitness for safe use.

Extensive work has been done on the modification of multi-walled carbon nanotubes (MWCNTs) to improve their characteristics. Here, polystyrene (PS) was adsorbed on the surface of MWCNTs by dispersion process, using toluene as medium. PS modified MWCNTs (PS-MWCNTs) have been dispersed in polymethylmethacrylate (PMMA) matrix to prepare composite, PS-MWCNTs/PMMA. It is expected that PS adsorbed at the surface of the MWCNTs will help in improving the interaction between MWCNTs and PMMA which results uniform and homogeneous dispersion of the former in later. Thus, synthesized composites were characterized by UV-Vis and FTIR spectroscopy to monitor the functionality of developed product. Electrical parameters including conductivity and dielectric properties were measured with the help of LCR meter. Electrical characters of the composites were explored by investigating the effect of contents of PS-MWCNTs on conductivity and dielectric properties. Percolation behaviour was examined and calculated value of percolation threshold was 0.1wt%.

The synthetic industry has destroyed the life span of human beings due to environmental pollution. The discharged organic pollutants can be degraded by many physicochemical techniques, among them the heterogeneous photocatalysis is distinctive. Nano zero-valent iron (NZVI) doped bismuth ferrite (BiFeO3) nanoparticles were composited with g-C3N4 to fabricate ternary NZVI@BiFeO3/g-C3N4 semiconductor photocatalyst. The facile fabrication was achieved through the hydrothermal approach. The characterization techniques such as X-ray diffraction, Fourier transform infrared and Scanning electron microscopy equipped with energy dispersive X-ray was used. The analysis confirmed the successful fabrication of the photocatalysts. The energy bandgaps of the prepared photocatalysts were measured by the Tauc plot method using a UV–visible spectrophotometer. The energy bandgap values suggest that the insertion of g-C3N4 improves the optical response of catalysts under visible light. The NZVI@BiFeO3/g-C3N4 was employed against Rhodamine B dye for photocatalytic oxidative degradation under sunlight radiations. The influencing parameters like pH, NZVI@BiFeO3/g-C3N4 concentration, oxidant dose, reaction time were optimized to obtain the best-suited conditions. Under optimized conditions (i.e. pH = 9, NZVI@BiFeO3/g-C3N4 = 10 mg/100 mL, oxidant = 18 mM, Time = 120 min) the g-C3N4 based composite photocatalyst showed ~97% oxidative degradation of Rhodamine B. Response surface methodology was used as a statistical tool to check the combinational effect of influencing parameters.

Introduction Ciprofloxacin is a broad spectrum synthetic antibiotic that is frequently used against gram negative and gram positive bacteria. The increasing use of ciprofloxacin by humans has also results its release in environment as it is detected in different water bodies [1]. The presence of antibiotics in aquatic environment could result the development of antibiotic resistant strains [2], which is a serious concern. The current analytical tools for its sensitive detection are mainly based on spectrometric or chromatographic techniques. Nevertheless these methods are time consuming and require extensive sample preparation steps. It is imperative to design sensitive and robust sensor setups for its rapid detection in water bodies. In this study, we designed molecular imprinted polymeric layers incorporated with graphene derivatives for electrochemical sensing of ciprofloxacin using interdigitated capacitors as transducer. These devices offer rapid response and have low fabrication costs. The combination of reduced graphene oxide (rGO) with molecular imprinted polymer (MIP) has shown enhanced sensitivity and selectivity thus, developing smart sensor devices for straightforward detection of ciprofloxacin. Experimental Graphene oxide (GO) was synthesized by oxidation of graphite powder following modified Hummer’s method. For preparing reduced graphene oxide (rGO), the as-prepared GO was dispersed in distilled water and treated with sodium borohydride as reducing agent at 70°C for about 12 hours. The resultant product was subjected to several washings and dried overnight at 65°C. Molecular imprinted polymer (MIP) was prepared using methacrylic acid (MAA) and ethyleneglycol dimethacrylate (EGDMA) along with ciprofloxacin as template structure in dimethylformamide (DMF). The as-prepared GO/rGO powder was added to above pre-polymer mixture to prepare respective composite coatings. Azoisobutyrnitrile (AIBN) was used to carry out thermally initiated free radical polymerization at 60 °C for 30 minutes. The resultant polymer mixtures were integrated with IDCs by spin coating. The non-imprinted polymer was prepared under same manner without adding template. Moreover, its composite layers with GO/rGO were prepared under similar conditions and integrated with IDCs. Results and Conclusion The sensor response as capacitance shift for rGO-MIP, GO-MIP, MIP and their corresponding non-imprinted layers i.e., rGO-NIP, GO-NIP and NIP was measured for varying concentrations of ciprofloxacin as shown in figure 1. Comparing the response of imprinted layers, it can be noticed that rGO-MIP coated IDCs showed highest sensor shift i.e. 43 µF, while GO-MIP is second best (34 µF) and finally, the pristine MIP is at third place (25 µF). This suggests that incorporation of rGO in MIP [3] enhances the sensor shifts and thus, is a suitable strategy for improving the sensitivity. On other hand, all the non-imprinted layers i.e., rGO-NIP, GO-NIP and pristine NIP showed much lower sensor shifts. Moreover, these layers showed similar sensor shifts indicating that these layers does not possess any specific recognition sites and thus, can be taken as control surface. The selectivity of rGO-MIP sensor is tested by exposing the device against structurally analogous antibiotic drugs. The sensor shifts of rGO-MIP for ciprofloxacin, levofloxacin and moxifloxacin in the concentration range 10-50 ppm is shown in figure 2. It is evident that sensor response for ciprofloxacin is at least 3 times higher than levofloxacin and moxifloxacin. The significantly higher sensor shifts for ciprofloxacin is due to the presence of complementary interaction sites in MIP layer. While levofloxacin and moxifloxacin despite of their similar structures to ciprofloxacin showed much lower sensor shifts. The results suggested that the incorporation of rGO to MIP not only improves sensitivity but also contribute in enhanced selectivity as well. References [1] H. Chen, B. Gao, H. Li, Removal of sulfamethoxazole and ciprofloxacin from aqueous solutions by graphene oxide, Journal of hazardous materials 282 (2015) 201-207. https://doi.org/10.1016/j.jhazmat.2014.03.063 [2] B. Fantin, X. Duval, L. Massias, L. Alavoine, F. Chau, S. Retout, A. Andremont, F. Mentré, Ciprofloxacin dosage and emergence of resistance in human commensal bacteria, Journal of Infectious Diseases 200(3) (2009) 390-398. https://doi.org/10.1086/600122 [3] W. Zheng, M. Zhao, W. Liu, S. Yu, L. Niu, G. Li, H. Li, W. Liu, Electrochemical sensor based on molecularly imprinted polymer/reduced graphene oxide composite for simultaneous determination of uric acid and tyrosine, Journal of Electroanalytical Chemistry 813 (2018) 75-82. https://doi.org/10.1016/j.jelechem.2018.02.022 Figure 1

The present work is centered on the study of electrical properties of three different types of composites i.e. single layer carbon black (CB) and multi-walled carbon nanotubes (MWCNTs) based PMMA composites, CB/PMMA and MWCNTs/PMMA, and bilayer polymer composites CB/PMMA-MWCNTs/PMMA, prepared by solution mixing method using chloroform as dispersion medium. It is expected that two layers in bilayer polymer composites would show increased interfacial interactions resulting in improved electrical character especially dielectric properties. Prepared composites have been characterized by UV-Vis and FTIR spectroscopy for successful synthesis. Electrical properties, conductivity, dielectric constant and tangent loss of all composites were measured at frequency range of 40Hz to 1MHz by using LCR meter. Percolation threshold value was obtained by using data of electrical conductivity as a function of volume fraction of fillers. The obtained value of percolation threshold was much lower for bilayer polymer composites i.e. 0.01 vol% as compared to the single layer polymer composites. Observed data of dielectric constant encourages the synthesis of composites with this kind of structure.