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The kinetics of ligand substitution reaction of Cu(methionine)2 complex by polyamines has been followed conductometrically above pH 9.0 at 25 oC. Millimolar solution of the Cu(NO3)2 and methionine in 1:2 molar ratio in water shows increase in conductance with time. When a polyamine (en, dien and trien) is added to the complex, the conductance increases at a rapid rate due to substitution of methionine by polyamine leading to the formation of [Cu(polyamine)2]. It was observed that the exchange of methionine by polyamine proceeds in a first order process. Since the rate of the reaction varies with the size of polyamines they can be placed in the following, en > dien > trien. In acidic pH range the absorption spectrum varies negligibly. However, the concentration of methionine does not have any influence on the absorption spectra.

In this study, zinc oxide (ZnO) as well as ZnO/GO (zinc oxide/graphene oxide) were successfully synthesized. The Carica papaya leaf extract was used to synthesize ZnO and oil palm empty fruit bunch biomass to obtain graphene, which was further used to obtain graphene oxide. The samples were characterized through a variety of analytical methods such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy and UV–Visible spectroscopy in order to understand their morphology, size, structural phase purity, functional groups and optical properties. Various peaks such as O-H, Zn-OH and Zn-O were found in the case of ZnO. Some additional peaks, such as C-C and C=C, were also been detected while analyzing the sample by Fourier-transform infrared spectroscopy. The results of the XRD and SEM studies demonstrated that the synthesized material shows the crystalline nature of the substance in the case of ZnO, and the crystallinity decreases for ZnO/GO. The average crystallite size was found to 80.0 nm for ZnO and 74.0 nm for ZnO/GO. Further, a red shift was shown in the case of ZnO/GO, which was indicated by the UV–Vis absorption spectrum. In the TEM analysis, the particles were shown to be nanosized. For instance, the highest number of particles was found in the range of 100 to 120 nm in the case of ZnO, while 80–100 nm sized particles were found for ZnO/GO. Using synthesized ZnO and ZnO/GO, the decolorization of methylene blue was found to be 64% and 91%, respectively.

Molecularly imprinted polymer (MIP) nanoparticles of Sudan III dye as template were synthesized by using non-covalent approach. The molecularly imprinted polymers were synthesized in a microemulsion contained Sudan III as a template, acrylic acid (AA) as a monomer, 1,4-butanediol dimethacrylate as a cross-linker and 2,2-azo-bisisobutyronitrile (AIBN) as an initiator. The synthesized beads were characterized by TEM and FTIR. The TEM results revealed the nanosize beads of polymers were produced. The efficiency of imprinted and non-imprinted polymers was evaluated by batch binding studies. The results showed that the MIP 3 (0.1: 6: 10, Sudan III: AA: 1,4-butanediol dimethacrylate) was best among all polymers with highest rebinding efficiency. The removal efficiency of selected MIP 3 in the spiked Sudan III dye river water sample was about 80%. This study was conducted to produce nanosized molecularly imprinted polymers by using microemulsion polymerization technique.

The use of agricultural by-products has been widely studied to develop effective and inexpensive adsorbent for heavy metal removal. In this study, sago (M.sagu) fly ash (FA) was chemically modified to afford an operational adsorbent for Pb (II) elimination from water. Chemical modification was carried out via acid-base treatment using NaOH and HCl. The chemically modified fly ash (MFA) was characterized via proximate, surface morphology, and functional groups' surface area analyses. The effects of adsorption parameters, namely, Pb (II) initial concentration, sorbent dosage and contact time on the eradication of Pb (II) by MFA was analyzed in batch experiments with Langmuir and Freundlich isotherms. Optimization of Pb (II) removal by MFA was studied via response surface methodology (RSM) approach. Results revealed that chemical modification has successfully enhanced the adsorptive properties of MFA (BET surface area: 231.4 m2/g, fixed carbon: 55.83%). MFA exhibits better Pb (II) removal efficiency (90.8%) compared to FA (63.6%) at the following adsorption condition: Pb (II) initial concentration (5 ppm), contact time (30 min) and agitation speed (150 rpm). The adsorption of Pb (II) by FA and MFA fitted well with Freundlich isotherm (R2>0.9). RSM study suggested that the optimum Pb (II) removal was 99.4% at the following conditions: Pb (II) initial concentration (20 ppm), contact time (2 h) and sorbent dosage (0.6 g/50 mL). The results concluded the potential optimum operational condition for Pb (II) removal from aqueous environment by MFA as a low cost adsorbent, at larger scale.

Electrical energy generation can be achieved in microbial fuel cells (MFCs) through the catalytic action of microorganisms which can oxidize organic matter and convert it into a biofilm. In MFCs, the exoelectrogens play a crucial role. MFCs is eco-friendly promising technology that produces electricity from various organic substrates. It is a novel and environmentally friendly approach for bioremediation and sustainable electricity production. The fact that heavy metals contributing adversely to the environmental pollution thus the microbial fuel cell technology has a solution for this as well, performing the removal and recovery of heavy metals by using both single and doublechambered MFCs. Many studies show that the new strains of microbes can produce power densities individually as high as strains from mixed communities. However, the implementation of this technology is just limited to the laboratory scale because of a few challenges like low efficiencies, low production rates. This review article focuses an introduction about the role and mechanism of different microorganisms towards energy production, biofilm formation, high power producing microbes inside the microorganisms, the electron transfer mechanism to the electrodes and vice-versa and the removal of heavy metals.

The molecularly imprinted polymers (MIPs) were prepared by using the non-covalent approach. In the polymerization process, xylenol orange was used as a template (T), acrylic acid as a functional monomer (M), divinylbenzene as a cross-linker (CL) and 2,2’-azobisisobutyronitrile (AIBN) as an initiator and microemulsion as a solvent. The synthesized polymers were characterized by using FTIR and SEM micrograph. The batch binding analysis was used to evaluate the rebinding efficiency of imprinted polymers. The highest rebinding efficiency was obtained from the MIP-R2 (0.1:0.6:2, T:M:CL). The selected MIP-R2 was used for the removal of xylenol orange from the water sample and have shown removal efficiency of about 80%.

Although regarded as environmentally stable, bioelectrochemical fuel cells or, microbial fuel cells (MFCs) continue to face challenges with sustaining electron transport. In response, we examined the performance of two graphene composite-based anode electrodes—graphene oxide (GO) and GO–polymer–metal oxide (GO–PANI–Ag)—prepared from biomass and used in MFCs. Over 7 days of operation, GO energy efficiency peaked at 1.022 mW/m2 and GO–PANI–Ag at 2.09 mW/m2. We also tested how well the MFCs could remove heavy metal ions from synthetic wastewater, a secondary application of MFCs that offers considerable benefits. Overall, GO–PANI–Ag had a higher removal rate than GO, with 78.10% removal of Pb(II) and 80.25% removal of Cd(II). Material characterizations, electrochemical testing, and microbial testing conducted to validate the anodes performance confirmed that using new materials as electrodes in MFCs can be an attractive approach to improve the electron transportation. When used with a natural organic substrate (e.g., sugar cane juice), they also present fewer challenges. We also optimized different parameters to confirm the efficiency of the MFCs under various operating conditions. Considering those results, we discuss some lingering challenges and potential possibilities for MFCs.

Recognition of sustainability issues around water resource consumption is gaining traction under global warming and land utilization complexities. These concerns increase the challenge of gaining an appropriate comprehension of the anthropogenic activities and natural processes, as well as how they influence the quality of surface water and groundwater systems. The characteristics of water resources cause difficulties in the comprehensive assessment regarding the source types, pathways, and pollutants behaviors. As the behavior and prediction of widely known contaminants in the water resources remain challenging, some new issues have developed regarding heavy metal pollutants. The main aim of this review is to focus on certain essential pollutants’ discharge from anthropogenic activities categorized based on land-use sectors such as industrial applications (solid/liquid wastes, chemical compounds, mining activities, spills, and leaks), urban development (municipal wastes, land use practices, and others), and agricultural practices (pesticides and fertilizers). Further, important pollutants released from natural processes classified based on climate change, natural disasters, geological factors, soil/matrix, and hyporheic exchange in the aquatic environment, are also discussed. Moreover, this study addresses the major inorganic substances (nitrogen, fluoride, and heavy metals concentrations). This study also emphasizes the necessity of transdisciplinary research and cross-border communication to achieve sustainable water quality using sound science, adaptable legislation, and management systems.

Silver nanowires and Ag@polycarbazole nanocables have been effectively fabricated. Polyol-reduction and ion adsorption process were used to fabricate pure silver nanowires and Ag@polycarbazole nanocomposite by using an oxidant (iron acetate). Ions of oxidant were adsorbed on the surface of pure silver nanowires to oxidize carbazole monomers for efficient polymerization. The morphology of nanowires and Ag@PCz composite were characterized by using SEM, FT-IR and photoluminescence analysis. The SEM shows the presence of a smooth polymeric sheath. FT-IR and photoluminescence analysis shows dominant peaks that indicate the presence of silver nanowires and polycarbazole (PCz) with a smooth polymeric coating. Nanoparticle analyzer was used to determine z-average and actual size of sample. UV-visible spectrum shows two bands that were dominant at 345 and 410 nm. These are π to π* transitions that indicates the presence of polycarbazole nanocables.

In present study, the molecular imprinting polymer (MIP) of p-coumaric acid was synthesized by using p-coumaric acid as a template, acetonitrile as solvent, 1,4-butanediol dimethacrylate as cross-linker, acrylic acid as monomer and 2,2-azobisisobutironitrile (AIBN) as the initiator. The synthesized polymers were characterized by FTIR and SEM. The results from SEM revealed that the polymer was in spherical shape with size in micro-range. The binding efficiency of polymers was analyzed by adsorption study. The highest rebinding efficiency for MIP was ~ 80% while for non-imprinted polymer (NIP) it was only 24%.

Background:2,4,6-Trichlorophenol (2,4,6-TCP) is one of the most significant pollutants among chlorophenols due to its harmful effects. It has been classified as priority pollutants by the U.S. Environmental Protection Agency. Therefore, highly selective separation and sensitive recognition of 2,4,6-TCP from complex samples are in great demand.Methods:For this purpose , the preparation of MIPs selective for 2,4,6-TCP was carried out by precipitation polymerization. A non-covalent approach was employed to establish an interaction between template and monomer (methacrylic acid).Results:The resulted polymers were characterized by scanning electron microscopy (SEM), EDX, Fourier-transform infrared spectroscopy(FT-IR) and BET. The batch binding assay was carried out to select the most selective polymer in terms of binding efficiency towards the target template. The adsorption parameters such as initial concentration, dosage of polymer, pH effect and selectivity with structural analogues were determined . The selectivity of MIP towards the 2, 4, 6-TCP was higher as compared to its structural analogue melamine with a good adsorption efficiency. Furthermore, the MIP as an extracting material was applied for extraction of 2, 4, 6-trichlorophenol from the spiked blood serum (88%) and river water sample (94%). The results showed that the optimized MIP could successfully extract 2,4,6-TCP from the blood serum and river water.Conclusion:The molecularly imprinted polymers for 2,4,6-TCP have been prepared by precipitation polymerization with a non-covalent approach. The optimized MIP has been successfully used for the extraction of 2,4,6-TCP from blood serum and river water.

In this article, molecularly imprinted polymer (MIP) of melamine was synthesized by non-covalent approach using microemulsion medium. In this study, melamine is used as a template molecule, acrylic acid as a functional monomer, N,N′-methylenebis(acrylamide) (MBAm) as a cross-linker and 2,2′-azobisisobutyronitrile (AIBN) as an initiator and microemulsion as a solvent. The produced polymers were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) and thermogravimetric analysis (TGA). The batch binding analysis was conducted for the evaluation of MIP and NIP rebinding efficiency with the melamine template. The adsorption studies including the adsorbent dosage of polymer, initial concentrations and pH of melamine solution were successfully carried out on both MIP and NIP. For selectivity test, 2,4,6-trichlorophenol was chosen as the competitive molecule against melamine template. A very good relative selectivity coefficient was achieved. The removal of melamine from different samples were conducted successfully by achieving a good removal efficiency in milk, river water and human blood serum 84.30, 94.26 and 93.32 %, respectively.

Molecularly imprinted polymers (MIPs) of melamine (MEL) were synthesized by non-covalent approach with precipitation polymerization. In this research, MEL was used as the template molecule,...

Molecularly imprinted polymers (MIPs) were prepared by precipitation polymerization using thymol as a template molecule, acrylamide as a functional monomer and N,N-methylbisacrylamide as the crosslinker with a non-covalent approach. The polymers were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), fourier-transform infra red spectroscopy(FT-IR) and Brunauer-Emmett-Teller (BET). The SEM results depicted that the shape of polymer particles is spherical with uniform size (micro-meters). The BET results also showed better surface area, pore size and pore volume of MIP as compared to non-imprinted polymer (NIP). A series of parameters such as initial concentration, polymer dosage, effect of pH and slectivity with structural analogue were conducted. The selectivity of MIP towards thymol was appreciable as compared to its structural analogue gallic acid with a relative selectivity coefficient of 3.59. Finally, MIP has been successfully used for extraction of thymol from the spiked blood serum (84 %) and river water sample (98 %).

Stimuli-responsive polymers are materials that can display remarkable changes in their properties with slight change in environmental conditions. Substantial change in the structure and properties can be made to the textiles by the incorporation of smart polymers into them. The following characteristics for intelligent polymers viz., thermal-, moisture-, and light-responsive polymers, and thermal- and pH-responsive hydrogels, have been incorporated into the fabrics to improve or achieve smart fabric functionalities. The functional components include esthetic appeal, comfort, drug release, fantasy design (color changing), wound monitoring, smart wetting properties, and protection against tough environmental alterations. In this chapter, the applications of stimuli-responsive polymer/composites in fabrics and the clothing field have been deliberated upon; the related issues on the fabrication of clothing and their potential applications in the years to come are elucidated.

Polymers have a sacred space in science. It is a well-known fact that due to some unique and specific properties polymers are used in a wide range of applications. Among them smart biopolymers have gained attention of researchers worldwide due to their unique properties such as biodegradability, biocompatibility, inexpensiveness, and renewability. Furthermore, these smart biopolymers show a characteristic property of responsiveness to stimuli such as temperature, pH, magnetic and electrical field, chemical, mechanical stress, and light. Consequently, succeeding chapter will briefly shed light about such smart biopolymers, their classification, and applications. Special attention is laid on the potential applicability of such smart biopolymers in the field of drug delivery, tissue engineering scaffolds, bioseparation, biotechnology, other medicinal fields, etc. The versatility and unique potential of these smart polymers make them one of the important parts of science, specifically medicine and drug delivery.

Microbial fuel cells (MFCs) are a sustainable approach for the remediation of metals and the simultaneous production of energy. This paper highlighted the usage of mango extract to produce electricity as an organic source for bacteria and reduce metal ions from wastewater. The observed results were 51 mV in 15 days with 500 Ω of external resistance. The whole operation was carried out at room temperature. The observed current and power density were 28.947 mA/m2 and 0.972 mW/m2, respectively. The internal resistance was 150 Ω, which is lower than external resistance. The remediation performance varied with the metal ions as follows: Pb (II) shows 75%, Cd (II) shows 74.11%, and Cr (III) shows 80.50%. Finally, the detailed working mechanism of the present study, MFC challenges, and future research directions are covered in this paper.

A new bioelectrochemical approach based on metabolic activities inoculated bacteria, and the microbial fuel cell (MFC) acts as biocatalysts for the natural conversion to energy of organic substrates. Among several factors, the organic substrate is the most critical challenge in MFC, which requires long-term stability. The utilization of unstable organic substrate directly affects the MFC performance, such as low energy generation. Similarly, the interaction and effect of the electrode with organic substrate are well discussed. The electrode-bacterial interaction is also another aspect after organic substrate in order to ensure the MFC performance. The conclusion is based on this literature view; the electrode content is also a significant challenge for MFCs with organic substrates in realistic applications. The current review discusses several commercial aspects of MFCs and their potential prospects. A durable organic substrate with an efficient electron transfer medium (anode electrode) is the modern necessity for this approach.

Graphene has obtained an excessive amount of interest and popularity from worldwide owing to its atypical physiochemical, chemical, thermal and mechanical stability-based properties. Graphene, a one atom thick plain sheet with sp2 bonding and the carbon atoms are compactly packed in structure to form crystal lattice. Many approaches are known to synthesize the graphene derivatives and therefore, it is essential to discuss a list of distinguished approaches like exfoliation and cleavage, thermal chemical vapor deposition etc. The most commonly used hybrid graphene nanocomposite synthesis approaches and their significant applications are also summarized in this chapter.

Polysaccharide nanocomposites have drawn attention for their peculiar property of being renewable and green alternatives. Starch is a naturally renewable polymer having great potential owing to properties such as total compostability, biocompatibility, biodegradability, and are without toxic residues, besides few limitations including low mechanical properties, high water sensitivity, and poor processability. However, insertion of nanofillers into starch nanocomposites results in substantial changes and improvements in the stability and applicability of starch-based nanocomposites. This chapter aims to provide the fundamental knowledge on the role of starch nanocomposite polysaccharides, as specific in the field of biomedical applications, especially in gene delivery, as well as recent developments in this area.

Enzymes play a vital role in a broad spectrum of fundamental physiological processes and therefore could be exploited as biological triggers to achieve a controlled release of cargo at the desired site. Enzyme-responsive materials are a class of stimuli-responsive materials with a variety of applications in biological systems. They have been proved to be potential biomaterials, biomedicine, and biosensing candidates. These types of smart materials undergo macroscopic changes when triggered by a selective action of enzymes. This idea has been applied successfully for the development of drug carrier systems where the tissue of interest is targeted by the release of cargo triggered by the catalytic action of an enzyme. This chapter mainly emphasizes on the few key enzyme-responsive nanomaterials such as proteases, lipases, and glucosidases and oxidoreductases for various biomedical applications.