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Carfentrazone-ethyl is embedded in guar gum to prepare a polymer-herbicide conjugate gel formulation for a sustained release of the active ingredient (a.i.). The sprayable gel formulation was optimized at 0.5% (w/v) concentration. Strong interactions of the prepared composition of the polymer-herbicide conjugate system are shown through spectroscopic techniques, depicting the peak broadening of hydrophilic -OH bonds in the herbicide at 1743 cm

BACKGROUND: Synthetic biopolymers have been widely used to manage bone effects in recent years. The study aims to analyse the ability to repair artificially created ulnar bone defects with the scaffold made of Polycaprolactone (PCL) and investigate the material's feasibility as a bone graft substitute. METHOD: We have tested a novel 3D biodegradable Polycaprolactone Poly-l-Lactide polymer scaffold in an experimental animal model. 14 adults New Zealand white rabbits were used to create the ulnar defect model of 10 mm in length, and randomly divided into group A (test-12 rabbits), group B (control-3 rabbits). The defect area was implanted with the PCL scaffold in the test group, whereas it was left as such in the control group. The repairing effect was observed by gross, histology, radiology, and the Scanning electron microscopy (SEM) at 4, 8, and 12 weeks. Cook's scoring was used to assess the radiological parameters. RESULTS: Histological and radiological results showed better quality of bone regeneration in the defect area at 12 week follow-up period. The SEM image at that period showed impregnation of the osteogenic cells in the surface and pores of the scaffold material. It was evident that the scaffold was thoroughly degraded, corresponding with osteogenesis. New bone formation was statistically significant in the test group than in the control group. CONCLUSION: The Polycaprolactone Poly-l-Lactide polymer scaffold is biodegradable in-vivo at a suitable half-life. It has an excellent porous structure, no tissue toxicity, excellent mechanical strength, high osteogenesis potential, and osteoconductivity. Therefore, it can be used as bone graft material in the gap non-union and as a void filler in bone defects.

Graphene oxide was chemically tagged with thermoplastic polyurethane, chain extended using butanediol to obtain the varying molecular weight of the polymer. Graphene-tagged polyurethane was functionalized using propane sultone to introduce the polar sulphonate groups in the main chain. The chain extension, tagging of GO and functionalization have been verified through spectroscopic techniques such as NMR, FTIR, UV and gel permeation chromatography. Thermal stability and the nature of the interaction were explored through thermal measurements to understand the effect of GO and functionalization. Electrical conduction was improved by the chemical attachment of graphene with the polymer (5.08 × 10

The current review article provides deep insight into the fluoropolymers and their applications in energy technology, especially in the field of energy harvesting and the development of fuel cell electrolyte polymeric membranes. Fluoropolymers have gained wide attention in the field of energy applications due to their versatile properties. The incorporation of nanofillers within the fluoropolymer to develop the nanohybrid results in an enhancement in the properties, like thermal, mechanical, gas permeation, different fuel cross-over phenomena through the membrane, hydrophilic/hydrophobic nature, ion transport, and piezo-electric properties for fabricating energy devices. The properties of nanohybrid materials/membranes are influenced by several factors, such as type of filler, their size, amount of filler, level of dispersion, surface acidity, shape, and formation of networking within the polymer matrix. Fluoropolymer-based nanohybrids have replaced several commercial materials due to their chemical inertness, better efficacy, and durability. The addition of certain electroactive fillers in the polymer matrix enhances the polar phase, which enhances the applicability of the hybrid for fuel cell and energy-harvesting applications. Poly(vinylidene fluoride) is one of the remarkable fluoropolymers in the field of energy applications such as fuel cell and piezoelectric energy harvesting. In the present review, a detailed discussion of the different kinds of nanofillers and their role in energy harvesting and fuel cell electrolyte membranes is projected.

With the depletion of the conventional energy sources, measures are being taken to create an alternate energy sources for the future. Energy harvesting from different sources are one of the better steps taken in this direction. Mechanical energy harvesting from the waste mechanical source is gaining profound investigation. Here, a nanohybrid of poly(vinylidene fluoride) and lead zirconia titanate (PZT) is prepared through solution route for energy harvesting applications. PZT is synthesized using solid state route and its concentration was varied in the nanohybrid to get the best properties from the hybrid. Structural and morphological aspects of the nanohybrid have been explored for their suitable application. Device has been fabricated using the nanohybrid to convert the waste mechanical energy from various human motions to the useful electrical energy. The device is able to generate a maximum output voltage of 55 V and a power density of 36 μ Wcm−2. The device is able to produce voltage output from different human motions such as finger tapping, feet tapping and bending. The mechanism of charge conversion is also discussed which explains the generation of such a high electrical output from waste mechanical source.

The present work is focused on the synthesis of morphology-controlled vertically aligned Zinc oxide (ZnO) nanosheets (NSs) using a high power low-temperature sonochemical process. The synthesis process is a facile and low-temperature process, which can be able to produce large-area, homogeneously-grown, vertically-aligned ZnO NSs with high surface to volume ratio. Also, using the same process, we have developed a low-temperature in-situ method of the magnesium (Mg), doped ZnO NSs with identical structure and morphology. The process is versatile, scalable and can be adopted for synthesizing various other doped morphology controlled nanosheets synthesis. The morphology and structure were confirmed using X-ray diffraction technique, FESEM, TEM/HRTEM while surface composition, bonding and doping were confirmed using XPS and UV–VISIBLE spectroscopy. We obtained 2D few layered thick ZnO nanosheets of flake size 2–5 μm with bandgap ∼3.38 eV, which was increased to ∼3.7 eV due to the Mg doping. Furthermore, we demonstrated the comparative photocatalytic activity of the as-synthesized pristine and doped ZnO nanosheets and found that Mg-doping promotes the faster catalytically active redox reaction, hence; the dye degradation time was 15 min faster compared to the pristine ZnO NSs under identical conditions. We believe that the rate-enhancement in photocatalytic dye degradation of Mg-doped ZnO NSs is obtained due to the faster hole transport properties and low recombination rate.

Despite 60% oral absorption, high first-pass metabolisms resulted in 2% oral bioavailability of raloxifene and also suffer poor water solubility. In this study, we developed the penetration enhancer rich hydrogel containing raloxifene-loaded solid lipid nanoparticles (RL-SLNs) for transdermal route. Interestingly, SLN offers higher solubility and thermodynamic activity due to amorphization of drug and evasion of first-pass metabolism by transdermal route. Cumulative effect will contribute to enhanced permeation flux, controlled drug release and enhanced bioavailability. Nanoparticles were synthesized using solvent emulsification–evaporation method and evaluated further for various physicochemical properties, ex vivo permeation and hydration studies. RL-SLN3 with particle size 227.9 ± 12.6 nm, polydispersity index 0.283 ± 0.021, zeta potential 15.4 ± 1.7 mV and entrapment efficiency 77.04 ± 5.08% was selected for further studies as optimized formulation. Differential scanning calorimetric method revealed that 54.75% of RL had changed to amorphous state adding to enhanced solubility. Furthermore, the results of ex vivo permeation studies on human skin elucidated that 10% d-limonene in combination with RL-SLN had excellent permeation flux (7.24 ± 0.49 µg/cm2 h) compared to RL-SLN alone and other penetration enhancers tested. Thus, the output of above studies suggested that transdermal delivery of RL-SLN using d-limonene as penetration enhancer can be a promising approach to evade the first-pass metabolism and increase the systemic bioavailability of RL.

In this current scenario, there is a broad range of use of resins in both domestic and industrial applications. Especially the importance of resins for adhesive in the wood industry is inevitable. But most of the commercially available resins for adhesive application are prepared of formaldehyde or fossil fuel-based resources which possess serious health issues. Henceforth, development of environmentally friendly resin from renewable resources through a cost-effective technique is a challenging task. Motivated by these facts and prospects, we present a novel technique for addressing non-renewability difficulties while also improving adhesive strength of the material. In this study, lignin-based composite resin with enhanced sustainability and adhesion strength have been achieved by a simply mixing of high concentration of poly (itaconic acid)-functionalized-lignin (P(IA)-f-Lignin) and aqueous emulsion of polyvinyl acetate. The P(IA)-f-Lignin was synthesized by in-situ free radical polymerization of partly neutralized IA in the presence of aqueous lignin dispersion at 90 °C using ammonium persulfate as initiator. The formation of P(IA)-f-Lignin was confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), field emission scanning electron microscope (FESEM) and thermogravimetric analysis (TGA). Here, we have been fabricated 20, 30, 40, 50, and 60 wt% of P(IA)-f-Lignin containing composite resin with desired amount of aqueous emulsion of polyvinyl acetate (PVAc). The changes in physico-chemical interactions were established by FTIR analysis. Various properties like viscosity, thermo-stability, and adhesive properties of all the formulated composite resin were inspected thoroughly. The composite containing 40 wt% of P(IA)-f-Lignin shows excellent improvement of adhesion strength from 3.32 ± 0.12 MPa to 7.83 ± 0.45 MPa. These fabricated composite resin with a high concentration of bio-based P(IA)-f-Lignin content and strong adhesion strength is very promising for fabrication of biobased adhesives with improved sustainability. publishedVersion

Cationic polymer-based gene delivery vectors suffer from several limitations such as low DNA-loading capacity, poor transfection, toxicity, environmental degradations, etc. Again, very limited works are available addressing the binding interactions in detail at the atomic level explaining the loading capacity, protection ability against harsh environments, and controlled release behavior of the DNA-encapsulated vehicles. Here, a poly(l-lactide) (PLA) nanoparticle-based controlled DNA release system is proposed. The developed vehicle possesses a high DNA-loading capacity and can release the loaded DNA in a controlled manner. Spectroscopic, physicochemical, and molecular simulation techniques (AM1 and atomistic molecular dynamics) have been employed to understand the binding interactions between PLA and DNA molecules enabling high DNA loading, protection against external harsh environments, and controlled DNA release behavior. Methyl thiazolyl tetrazolium (MTT) assay experiments confirm the biocompatible nature of the vehicle. Cellular uptake efficiency and endo-lysosomal escape capabilities have been investigated against HeLA cells. This study, therefore, demonstrates the development of a promising nonviral DNA delivery vector and includes a detailed investigation of the atomic-level interaction behavior between PLA and DNA molecules.

Passive radiative cooling is an emerging field and needs further development of material. Hence, the computational approach needs to establish for effective metamaterial design before fabrication. The finite difference time domain (FDTD) method is a promising numerical strategy to study electromagnetic interaction with the material. Here, we simulate using the FDTD method and report the behavior of various nanoparticles (SiO2, TiO2, Si3N4) and void dispersed polymers for the solar and thermal infrared spectrums. We propose the algorithm to simulate the surface emissive properties of various material nanostructures in both solar and thermal infrared spectrums, followed by cooling performance estimation. It is indeed found out that staggered and randomly distributed nanoparticle reflects efficiently in the solar radiation spectrum, become highly reflective for thin slab and emits efficiently in the atmospheric window (8–13 µm) over the parallel arrangement with slight variation. Higher slab thickness and concentration yield better reflectivity in the solar spectrum. SiO2-nanopores in a polymer, Si3N4 and TiO2 with/without voids in polymer efficiently achieve above 97% reflection in the solar spectrum and exhibits substrate independent radiative cooling properties. SiO2 and polymer combination alone is unable to reflect as desired in the solar spectrum and need a highly reflective substrate like silver.

Novel biocompatible and brush copolymers have been developed for cancer treatment using its controlled drug-release potential. Polyurethane graft on linear dextrin has been synthesized to control the hydrophilic–hydrophobic balance for regulated drug delivery. The properties of the graft copolymers have been tuned through graft density. The prepared grafts are thermally stable and mechanically strong. An injectable hydrogel has been developed by embedding the drug-loaded brush copolymers in methyl cellulose to better control the release for a prolonged period, importantly by keeping the drug release at a constant rate. Cellular studies indicate the biocompatible nature of the brush copolymers whose controlled and slow release of drug exhibit significant cytotoxic effects on cancer cells. Endocytosis of drug tagged contrast agent indicates greater transport of biologically active material inside cell as observed through cellular uptake studies. In vivo studies on melanoma mice exhibit the real efficacy of the controlled drug release from the injectable hydrogel with significant melanoma suppression without any side effects as opposed to severe toxic effects observed in conventional chemotherapy. Special application method of drug-loaded hydrogel just beneath the tumor makes this system incredibly effective through confinement. Thus, brush copolymer injectable hydrogel is a promising vehicle for control release of drug for cancer treatment in future.

A bio-based piezoelectric egg shell membrane (ESM) is used for energy harvesting applications in the form of two and three-component nanohybrids. A bio-waste piezo-filler in a piezoelectric polymer matrix was designed through an induced β-phase nucleation in the matrix using an organically modified two-dimensional nanoclay. Structural alteration (α to β-phase) in the presence of the nanoparticles was also manifested by morphological changes over spherulite to a needle-like morphology; thus, these nanohybrid materials are suitable for energy harvesting applications. ESM-based nanogenerators were fabricated with local ordering of piezo phases, as revealed via atomic force microscopy, leading to the generation of mostly electroactive phases in the whole nanohybrid. The voltage outputs from the optimized device were measured to be ∼56 and 144 V in single and multiple stacks (five), respectively, with corresponding power densities of 55 μW cm−2 and 100 μW cm−2. The efficiency of the device was verified using a variety of body movements, e.g. bending, twisting, walking, and foot tapping, causing mechanical energy dissipation, which eventually transformed into energy storage. The underlying mechanism of high conversion of energy is explained by the synergistically induced piezo-phase in the polymer matrix together with the floppy piezo-filler. The mechanical stability, durability and repeated energy conversion of the hybrid device make it a robust nanogenerator. The biocompatibility of the nanogenerator was verified through cellular studies, demonstrating its appropriate use in powering biomedical devices/implants.

Correction for ‘Nanochannel conduction in piezoelectric polymeric membrane using swift heavy ions and nanoclay’ by Karun Kumar Jana et al., RSC Adv., 2013, 3, 6147–6159. DOI: 10.1039/C3RA23176C

Single phase equi-atomic (Al0.2Co0.2Fe0.2Mn0.2Ni0.2)3O4 high-entropy oxide (HEO) having spinel structure was synthesised employing simple and cost effective microwave assisted co-precipitation technique, followed by calcination at 500 °C. The material obtained was highly crystalline and stable at higher temperatures. The uniformity in elemental distribution was apprehended through STEM-EDS elemental mapping. The X-ray photoelectron spectroscopy confirmed +3 ionic state for Fe and Al, while other elements oxidised to higher ionic states to maintain charge neutrality. Ferrimagnetic behaviour was confirmed for the obtained HEO through magnetic characterisations.

The wide range of applicability of poly(ethylene terephthalate) (PET) in various fields such as packaging, automobile parts, sports and textile due to its transparent nature, light weight and mechanical properties creates strong case to enhance its mechanical properties. By embedding nanofillers and thereby improving the mechanical properties, this spectrum can further be widened. The effect of addition of nanofiller in terms of stress concentration is a crucial phenomenon to understand the mechanical property enhancement. The nanohybrids of poly(ethylene terephthalate) (PET) and organically modified nanoclay have been prepared through solution casting route to enhance the properties significantly without any trade-off of deteriorating other properties. The dispersion of nanoclays in the polymer matrix has been observed through TEM images. Good level of dispersion has been achieved in nanohybrids due to specific interactions between nanoclay and PET matrix explored through XRD and FTIR spectroscopic measurements. Thermal stability of the nanohybrids has been tested through TGA and DSC analyses. The mechanical properties have been tested and found to be enhanced in the presence of nanoclay with increasing filler concentrations. The modulus has been increased for nanohybrids up to 93%, while the optimum value of modulus and toughness has been observed at 4 wt% filler percentage. The improvement in mechanical properties has been predicted using different models for randomly dispersed filler and has been found to be fitted in acceptable range. The hardness of the nanohybrids has been tested using Vickers hardness test and is found to be increasing continuously with filler loading. The structural formations upon uniaxial stretching have been contemplated through two-dimensional small-angle X-ray scattering as well as through wide-angle XRD. The nanohybrids have shown short-range ordering on uniaxial stretching in comparison with pristine PET. Blob size has been found out using Debye–Bueche model and is found to be increased upon stretching the samples. The polymer nanohybrids have been prepared for the mechanical property improvement without imparting high brittleness for practical applications. The behavior of nanoclay on stretching the polymer nanohybrids has also been studied in detail.

The present investigation is focused on the in-situ synthesis of Graphene oxide (GO)-ferrite nanoparticle hybrid framework by gel-combustion method followed by fabrication of homogeneous, structurally stable thin (~100–120 μm) hybrid-polyurethane coating on a metallic aluminum substrate and its application on the properties of broadband absorption over the microwave frequency region. Microstructure studies of hybrid materials illustrated that small sized ferrite nanoparticles (~17 nm) are grafted on and through the graphene layers, which forms a homogeneous coating thereby. The hybrid-nanocomposite coating demonstrated superior broadband absorption properties with absorptivity higher than 90% throughout a bandwidth of ~6 GHz, and moreover, it was found that with increased loading of GO in the nanocomposite, the bandwidth range of absorption frequency increases with enhanced absorptivity. The real part and imaginary part of the surface impedance values of the coating was obtained as 377 Ω and 0 Ω, respectively, which imply that the free-space impedance of the hybrid-nanocomposite coating is matching correctly. The nanocomposite coating showed ultra-high absorptivity over the frequency band of 8–12 GHz, which has numerous practical applications as radar absorbing materials (RAM), stealth technology, electromagnetic shielding, and radiated electromagnetic interference (EMI) management in onboard spacecraft and many more.

In-situ inclusion of different nanoclays during synthesis results in different level of dispersion of nanoclays in the polymer matrix depending upon the surface modification of the nanoclay. Higher intercalation of the polymer chains within the galleries of organically modified nanoclay results better dispersion as compared to pristine nanoclay. The spectroscopic measurement shows that the extent of interaction between the nanoclay and polymer chains is higher in modified nanoclay nanocomposite which decreases the crystallinity considerably as compared to pristine clay nanocomposite. Interestingly, shape memory behavior measured at physiological temperature (37 °C) improves significantly in presence of organically modified nanoclay while it decreases in presence of unmodified nanoclay in same polyurethane matrix. Complete melting of soft segment along with restricted flipping of hard segment with temperature in presence of extensive interaction in nanocomposite with modified nanoclay helps it to achieve better shape memory behavior against flipping induced stacking of hard segment with temperature along with poor interaction decreases its shape memory behavior in nanocomposite with unmodified nanoclay. Temperature dependent nanostructure reveals the cause of variation in shape memory behavior in presence of organically modified nanoclay. Further, the cell culture studies like cell adhesion, cell viability assay and fluorescence imaging, suggest superior biomaterial of the nanocomposite with modified nanoclay as compared to other composite. Better biodegradable nature of the modified nanocomposite makes it suitable candidate for its potential biomedical applications.

Process and nanoparticle induced piezoelectric super toughened poly(vinylidene fluoride-co-hexafluoro propylene) (HFP) nanohybrids have been developed for device application. The nanohybrids have been prepared by incorporating organically modified nanoclay through solution route. The nanohybrids show improvement in toughness and modulus along with piezoelectric phases compared to pure HFP. Piezoelectric phase has further enhanced to 75% in nanohybrid after uniaxial stretching of the thin film at moderately high temperature as compared to meager 18% beta-phase before stretching. The structural changes including quantitative measurements have been confirmed through X-ray diffraction, spectro-scopic and thermal studies. The structural and morphological origins of super toughening phenomena have been worked out. The piezoelectric and pyroelectric coefficients (d33 and p) exhibit significant increase after stretching at high temperature and the relative improvements are more in nanohybrid than that of pure HFP, arising from the presence of greater amount of b-phase in nanohybrid. The effect of structure on ferroelectricity has been studied through polarization-electric field hysteresis loop confirming greater maximum polarization, remnant polarization and coercive field for nanohybrid against pure HFP. Finally, fabrication of the unimorph has been performed using the high piezoelectric coefficient materials. The greater voltage generation under impulse load is demonstrated for nanohybrid along with longer time response vis-a-vis pure HFP clearly indicating the superior piezoelectric device made using nanohybrid where the extent of piezoelectric phase is considerably higher. (C) 2016 Elsevier Ltd. All rights reserved.

Thermoreversible gelation of three different isotactic linear poly(N-isopropylacrylamide) (PNIPAM)s having meso dyad (m) values 62, 68 and 81% has been observed in benzyl alcohol. All the gels were transparent in nature. SEM image of the dried gels showed fibrillar network morphology. Melting temperature of the gels gradually increased with the increase in the concentration. XRD data of dry polymers and their corresponding dry gels showed shifting in the peak positions. Rheological study showed that stronger gels were formed with increasing isotacticity of PNIPAM while lower isotactic sample exhibited typical polymer melt rheology. The formation of a plunge in the storage modulus as well as in the viscosity plot at the same frequency range indicates the reversible nature of the structure breaking/reformation under frequency sweep. Moreover, the mechanical strength of the gel decreased with increase in temperature. UV-Vis kinetic study also indicated the change in the conformation and aggregation of PNIPAM chains during gelation. Molecular modelling calculation showed that the number of solvent molecules involved in forming gel (polymer-solvent compound) decreased with the increase in the isotacticity of the polymer. Gelation rate of these gels was studied as a function of temperature, concentration and isotacticity using test-tube tilting method. It increased with the increase in the concentration and isoacticity of the polymer, and with the decrease in the temperature. Critical gelation concentration of the gel gradually increased with the decrease in the isotacticity and with the increase in the temperature. All these experimental results indicated that gelation occurs presumably through polymer-solvent compound formation.

Passive photonic radiative cooling is used to make sky exposed surfaces sub-ambient with recent development in metamaterials throughout the day and night cycle. Daytime radiative cooling depends on the intensity of solar radiation, and both daytime and nighttime radiative coolings have a function of environmental factors like ambient temperature, humidity, wind velocity, cloud fraction, etc. Hence, the passive radiative coolers have location-specific performance and need analysis individually for a location before implementation. In this paper, the potential of passive radiative cooling for Indian cities of various climatic conditions covering maximum climate diversity is evaluated for different (ideal, broadband and selective) emissive radiative cooler surfaces. The effects of various environmental parameters on the cooler performance are studied. The cooling energy-saving potentials of various photonic radiative coolers as roof envelope integrated with the conventional air conditioning system are evaluated as well. Results reveal that the selective radiative cooler performs better in low humidity locations, namely Jaisalmer and Delhi, with maximum temperature drops of 20.6 °C and 17.3 °C, respectively. However, it is less likely to recommend for monsoon season and high humid cities. The cooling load reduction of 36% observed for low humidity locations with an integrated system.

We report the synthesis of Mg0.5Zn0.5Fe2O4 (MZF) nanoparticles by gel combustion technique followed by fabrication of thin layer (~ 100 μm) of ferrite–polymer nanocomposite on aluminum substrate and its application on broadband absorption properties over the microwave frequency range of 4–15 GHz. The particle size of ferrite powder was controlled by changing citrate to nitrate molar ratios of precursors, which exhibit different adiabatic isotherms. XRD analysis showed that ferrite phase formation occurred for all systems and the system with lowest crystallite size (~ 30 nm) was obtained for the stoichiometric citrate to nitrate molar ratio. The nanocomposite coating showed excellent broadband absorption properties with absorptivity greater than 88%. This implied that the real and imaginary part of the surface impedance values of the nanocomposite coatings are close to 377 Ω and 0 Ω respectively, which is impedance of free space over the significant region of the frequency band of interest. The stoichiometric fuel based MZF of smallest average particle size showed best microwave absorption properties. The as-developed MZF nanocomposite coating showed minimum reflection from the coating over this frequency band, which can solve various electromagnetic interference issues, stealth technology, and the radiated EMI management in on board spacecraft and several others.

Hydrophilicity of cyclodextrin is controlled through grafting of polyurethane of varying graft density, thereby maintain the hydrophilic-hydrophobic balance, to sustain the drug delivery rate for better tumor treatment. Grafting is verified through nuclear magnetic resonance (1H NMR) and other spectroscopic techniques along with the hydrodynamic volume measurement of grafted species and the degree of substitution has been calculated from the integrated peak areas. Thermal and mechanical stability of the graft copolymers have improved significantly with respect to cyclodextrin and the formation of smaller blobs having larger in number has been obtained from small angle neutron scattering, atomic force microscopy and optical images. Sustained drug delivery has been achieved using graft copolymer as opposed to burst release in pure cyclodextrin and polyurethane and the phenomenon is understood from the specific interactions, as observed though spectroscopic and thermal measurement, between graft copolymer and drug followed by this novel architecture of the graft copolymers. Biocompatibility of graft copolymers has been checked using cellular studies through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cell adhesion. Importantly, the cell killing efficiency has been demonstrated by embedding anti-cancer drug in polymer matrices causing mortality rate of 80% using graft copolymer against meagre 20% using pure drug or drug embedded in cyclodextrin and the result is realised from the sustained release of drug from the graft copolymer vis-a-vis burst release in other systems. Cellular studies have been translated into an animal model showing the efficacy of newly developed patch, made of drug embedded in copolymer, towards the significant suppression of tumors in mice as compared to control. Histopathological images and biochemical parameters indicate the normal body organ/blood in copolymer treated mice against severely damaged organ especially liver/blood in the mice treated with pure drug or drug embedded in cyclodextrin arising from burst release. Thus, graft copolymer with unique architecture is found to be an effective drug delivery vehicle for melanoma cancer treatment without side effect.

Although conventional chemotherapy has been successful to some extent, the main drawbacks of chemotherapy are its poor bioavailability, high-dose requirements, adverse side effects, low therapeutic indices, development of multiple drug resistance, and non-specific targeting. The main aim in the development of drug delivery vehicles is to successfully address these delivery-related problems and carry drugs to the desired sites of therapeutic action while reducing adverse side effects. In this review, we will discuss the different types of materials used as delivery vehicles for chemotherapeutic agents and their structural characteristics that improve the therapeutic efficacy of their drugs and will describe recent scientific advances in the area of chemotherapy, emphasizing challenges in cancer treatments., Cancer therapeutics: Special delivery Improving the delivery of cancer therapies to tumor sites is crucial to reduce unwanted side effects and patient mortality rates. Pralay Maiti and colleagues at the Indian Institute of Technology in Varanasi, India, review the latest developments in drug delivery vehicles and treatment approaches designed to enhance the effectiveness of current cancer therapies. New nanoparticle-based carriers, hydrogels and hybrid materials that offer controlled and sustained drug release are showing great promise in animal models. Furthermore, materials that respond to stimuli such as heat, light, magnetic or electric fields are also being tested to aid target-specific drug delivery and, thus, avoid damage to healthy tissues. Although there are some challenges in translating these findings to the clinic, there is no doubt that technological advances are shaping better and safer treatment options.

Amine-functionalized graphene has been chemically tagged within long-chain polyurethane molecules, using graphene as a chain extender to prepare a nanohybrid, and its novelty has been explored by comparing its properties with those of physically dispersed functionalized graphene in polyurethane based on di-ol as a chain extender. Chemical tagging has been confirmed through NMR studies and the nature of the interaction between the polymer matrix and graphene (nanofiller) is stronger in the chemically tagged nanohybrid compared to a nanohybrid prepared through physical mixture, as revealed from FTIR, UV-visible and PL spectroscopic measurement. A homogeneous dispersion of graphene platelets is achieved through a chemically tagged nanohybrid as against the agglomerated nanostructure found in a physically mixed nanohybrid. Enhancement of thermal properties and toughening of the nanohybrids is observed, whose extent is significantly higher in the chemically tagged nanohybrid due to greater interactions between the components and the uniform dispersion of nanofiller. Graphene-induced self-assembly from the nanometer scale to the micron level (step by step) was investigated through X-ray diffraction, small angle neutron scattering, atomic force microscopy and optical images in the order of nanometer, tens of nanometer, hundreds of nanometer and micron size, respectively. The effects of self-assembly on drug release and the biocompatible nature of the nanohybrids were monitored using HeLa cells, looking at cell viability, cell adhesion and fluorescence imaging. Significant sustained release of an anti-cancer drug was obtained using the chemically tagged nanohybrid and understanding gained of its kinetic behavior and mechanism. The greater biocompatibility of the chemically tagged nanohybrid was revealed through cell adhesion and fluorescence imaging, demonstrating a superior biomaterial which delivers the anti-cancer drug in a sustained manner. Hence, the developed nanohybrid is a potential biomaterial for drug delivery and tissue engineering.

The disposal of non-degradable plastics has increased exponentially as a result of poor recycling efficacy. The development of biodegradable plastics has become indispensable over the last two decades because of their origin from renewable resources. The potential interest in biodegradable plastics comes from the eco-friendly obliteration via microbial action which transforms the plastics into carbon dioxide and water resulting in a pollution-free natural system. Even though the lucrative interest lies in multiple areas, some of the properties such as brittleness, and poor thermal, mechanical and low gas barrier properties restrict their practical uses. The incorporation of nanoparticles in the polymer matrix or the fabrication of nanocomposites overcomes the shortcomings of the biodegradable polymers. To improve the aforementioned properties further, several approaches have been utilized, especially the incorporation of nanoparticles in the polymer matrix to prepare nanocomposites. One of the great advantages of nanoparticles is the ability to tune the rate of biodegradation (it is possible to both increase and decrease the rate as compared to that of the pure polymer) depending upon the need. Thus, chemical, physical and biological properties of the biodegradable polymers can be modified and controlled for sustainable applications in medicine and other areas. This review considers the major concerns of biodegradable polyesters and their nanocomposites, great details about the mechanism of their biodegradation, factors influencing their biodegradation and their applications in biomedical and packaging industries.

Through nanochannels are fabricated in poly(vinylidene fluoride-co-hexafluoro propylene) films by bombarding swift heavy ions ( SHI ) of energy 80 MeV and thereby creating latent tracks in the ion passage followed by chemical etching of the amorphous track. The dimension of the nanochannel is varied from 34 to 65 nm using different fluences and by dispersing organically modified nanoclay in polymer matrix. The nanochannels are grafted with polystyrene using the free radicals caused by SHI irradiation followed by their sulfonation. Nanoclay nucleates piezoelectric β -phase in copolymer whose extent gets enhanced after irradiation, grafting and sulfonation leading to a better material. The efficiency of functionalized nanochannel conduction is studied through dc conductivity of the bulk film in the semiconducting range against the insulating nature of the pristine copolymer. Current-voltage (I–V) characteristic of the membrane exhibits strong fluence dependency and shows superior conduction in functionalized nanohybrid. Proton conductivity of the functionalized nanohybrid is 6.2 × 10 −2 S cm −1 , while methanol permeability drastically reduces indicating higher values of the selective parameter of the developed membrane as compared to Nafion. Membrane electrode assembly studies of functionalized nanohybrid show 0.63 V as open circuit voltage leading to power density of 30.8 mW/cm 2 , considerably higher than the functionalized copolymer.

Steady state and time-resolved spectroscopic measurements are carried out to understand the fluorescent optical properties of the conjugated polymer poly(9,9-di-(2-ethylhexyl)-9H-fluorene-2,7-vinylene) (PFV) in liquid phase and solid phase. Quite significant color tuning is observed in the fluorescence emission of PFV in the blue side of the spectra in the solid phase, especially in powder form, when the polymer is doped with 30B nanoclay (organically modified Montmorillonite) and graphene nanoparticles. Interestingly, the average fluorescence lifetime of PFVgraphene nanocomposite in thin film is found to be much higher (8.1 ns) compared to that for PFV only in thin film (3 ns). These novel nanocomposites may have potential applications in polymer optoelectronics industry.

Functionalization of poly(vinylidene fluoride) (PVDF) nanohybrid has been performed in template system using two-dimensional layered silicate and superior fuel cell membrane has been demonstrated. Sulfonation of nanohybrid has been carried out at control condition to maintain the mechanical stiffness and toughness of the membrane using chlorosulfonic acid and the results have been compared with pure PVDF. The sulfonation and its relative extent have been confirmed through NMR, FTIR and UV–vis measurements showing greater degree of functionalization in nanohybrid which arises from the specific arrangement of polymer chains on top of nanoplatelets. The structural change over from common crystallized form α- to piezoelectric β-phase in nanohybrid has been established and the amount of β-phase has been enhanced after sulfonation as evident from deconvoluted XRD patterns and DSC measurement. A plausible mechanism has been proposed for this improvement which led to the formation of smart membrane. Essential criteria of an ideal membrane have been verified through high water uptake, low permeability and hydrophilic nature by measuring contact angle. The molecular level clustering due to the attachment of sulfonate group in main chain has been explored which in turn explain the higher barrier property both for gas and liquid (fuel). Proton conductivity of functionalized nanohybrid has been found to be quite high along with significantly low methanol cross over as compared to standard Nafion membrane. I–V characteristics of the nanohybrid membrane show high potential at low current density with considerably lower value of slope. Membrane electrode assembly using functionalized nanohybrid exhibit significantly high value of current density and prove its worth for superior fuel cell membrane using common thermoplastic polymer.

Tadpole-shaped β-cyclodextrin-tagged poly(N-vinylpyrrolidone) (β-CD-PNVP) has been synthesised via the click reaction of alkyne-terminated PNVP and azide-functionalized β-CD. The formed polymer is characterized by 1H NMR, FTIR, and TGA study. The complexing ability of such a polymer with phenolphthalein is considerably lower with respect to that with β-CD alone. Doxorubicin (DOX)-loaded β-CD-PNVP (DOX-β-CD-PNVP) exhibits higher tumoricidal activity against a panel of tumor cell lines derived from sarcoma (U2-OS) and carcinomas (MCF-7 and HEPG2), causing significant lysis of tumor cells compared to free DOX. The formulation also demonstrates significantly higher uptake by the tumor cells and enhances apoptosis compared to free DOX.

PVDF has been reinforced with different amount of CaCu3Ti4-5x/4NbxO12 with x=0.05 powder prepared by solid state ceramic method. Composites were prepared by melt extrusion method. Phase composition was studied using powder X-ray diffraction (XRD). Microstructural, dielectric, and mechanical properties have also been studied. These composites have Young’s modulus more than that of pure PVDF. Two dielectric relaxations, one at low frequency and the other at high frequency, have been observed in these composites. Dielectric relaxation at low frequencies is of Maxwell-Wagner type while the one observed at high frequency is due to hopping of electrons among different valent states of transition metal ions. Nature of dielectric relaxation has been analysed using H-N function.