Solvent-Selective Fluorescence Sensing of Mg2+ and Al3+ Ions by Pincer-Type NNO Schiff Base Ligand: An Experimental and DFT Optimized Approach.

A newly developed dual-functional fluorescence sensing probe (phenylhydrazinyl pyridine) Schiff base (SB) has been designed with good selectivity for distinguishing Mg2+ and Al3+ metal ions in different solvent solutions. SB exhibits quick and visual turn-on fluorescence enhancement in response to Mg2+ and Al3+ detection. The addition of Mg2+ in ACN-HEPES buffer (1:1, v/v, pH 7.2) at (λmax = 390 nm) and Al3+ in MeOH-HEPES buffer (1:1, v/v, pH 7.2) at  (λmax = 360 nm) resulted in significant enhancement of fluorescence, up to 7 - 9 times. These low detection limits of 7.1 × 10-6 M (7.1 µM) and 5.15 × 10-7 M (0.51 µM) for Mg2+ and Al3+, respectively, have been achieved by this solvent-controlled platform. Due to the sensing potential towards Mg2+, the probe was utilized as an imaging material for breast cancer cells. 1H-NMR studies were utilized to explore SB's sensing mechanism through turn-on fluorescence. Density functional theory (DFT) calculations were utilized to validate optimized SB and its intricate geometries, which govern the sensing mechanism in the solvent environment. Such a probe has extensive potential applications in bioimaging and the assessment of the quality of wastewater.

Stimuli-Responsive Chiral Cellulose Nanocrystals Based Self-Assemblies for Security Measures to Prevent Counterfeiting: A Review.

The proliferation of misleading information and counterfeit products in conjunction with technical progress presents substantial worldwide issues. To address the issue of counterfeiting, many tactics, such as the use of luminous anticounterfeiting systems, have been investigated. Nevertheless, traditional fluorescent compounds have a restricted effectiveness. Cellulose nanocrystals (CNCs), known for their renewable nature and outstanding qualities, present an excellent opportunity to develop intelligent, optically active materials formed due to their self-assembly behavior and stimuli response. CNCs and their derivatives-based self-assemblies allow for the creation of adaptable luminous materials that may be used to prevent counterfeiting. These materials integrate the photophysical characteristics of optically active components due to their stimuli-responsive behavior, enabling their use in fibers, labels, films, hydrogels, and inks. Despite substantial attention, existing materials frequently fall short of practical criteria due to limited knowledge and poor performance comparisons. This review aims to provide information on the latest developments in anticounterfeit materials based on stimuli-responsive CNCs and derivatives. It also includes the scope of artificial intelligence (AI) in the near future. It will emphasize the potential uses of these materials and encourage future investigation in this rapidly growing area of study.

Investigating the Reactive Reinforcement Ability of Maleic Anhydride-Modified Cellulose Nanocrystals via In-Situ Emulsion Polymerization.

CNC-based nanocomposites have gained substantial interest because of their enhanced thermomechanical properties for high-end engineering applications. The chemical modification of CNCs expands their applicability, making them suitable for use in hydrophobic polymer matrices. The current study investigates the reactive reinforcing ability of maleic anhydride-modified cellulose nanocrystals during the in situ polymerization of a vinyl monomer, i.e., styrene. Highly crystalline nanocellulose (CNCBG) was isolated from Lagenaria siceraria (Bottle gourd) peels via Hydrochloric acid, which was further modified to synthesize maleic anhydride-modified cellulose nanocrystals (MACNCBG) and characterized employing various techniques. MACNCBG exhibited higher suspension stability than CNCBG due to the introduction of carboxyl groups. Furthermore, polystyrene-based nanocomposites of 3 and 5 wt % filler loading were prepared, respectively. While PSMACNCBG (5 wt %) displayed a premature failure, PSMACNCBG (3 wt %) demonstrated enhanced mechanical properties compared to PSCNCBG (3 wt %) and PS. At the same filler loading, MACNCBG demonstrated a more remarkable reinforcing ability than CNCBG, owing to its reactive tendency. The appearance of a new peak between 3000-2800 cm-1 corresponds to the C-H stretching of the formed C-C bond (between C=C of MACNCBG and benzal carbon of PS) in the FTIR spectra, confirming the reactive nature of MACNCBG.

Harnessing the Flexibility of Lightweight Cellulose Nanofiber Composite Aerogels for Superior Thermal Insulation and Fire Protection.

Thermally insulating materials from renewable and readily available resources are in high demand for ecologically beneficial applications. Cellulose aerogels made from lignocellulosic waste have various advantages. However, they are fragile and breakable when bent or compressed. In addition, cellulose aerogels are flammable and weather-sensitive. Hence, to overcome these problems, this work included the preparation of polyurethane (PU)-based cellulose nanofiber (CNF) aerogels that had flexibility, flame retardancy, and thermal insulation. Methyl trimethoxysilane (MTMS) and water-soluble ammonium polyphosphate (APP) were added to improve the cross-linking, hydrophobicity, and flame-retardant properties of aerogels. The flexibility of chemically cross-linked CNF aerogels is enhanced through the incorporation of polyurethane via the wet coagulating process. The aerogels obtained during this study have exhibited low weight (density: 35.3-91.96 kg/m3) together with enhanced hydrophobic properties, flame retardancy, and decreased thermal conductivity (26.7-36.7 mW/m K at 25 °C). Additionally, the flame-retardant properties were comprehensively examined and the underlying mechanism was deduced. The aerogels prepared in this study are considered unique in the nanocellulose aerogel category due to their integrated structural and performance benefits. The invention is considered to substantially contribute to the large-scale manufacture and use of insulation in construction, automobiles, and aerospace.

Recent advances in hydrophobic nanocellulose aerogels for oil spill applications: A review.

In a rapidly growing world, petroleum is used extensively in various industries, and the extraction, processing, and transportation of petroleum generates large amounts of petroleum-containing wastewater. Conventional oil/water separation methodologies are often ineffective and costly. Nanocellulose-based aerogels (NA) have emerged as a possible solution to this problem. However, hydrophobic modification is required for effective use in oil/water separation. This review on materials commonly used in these processes and outlines the requirements for adsorbent materials and methods for creating unique lipophilic surfaces. New trends in hydrophobization methods for NA are also discussed. Additionally, it includes the development of composite nanocellulose aerogels (CNAs) and cellulose based membrane specially developed for oil/water (o/w) separation considering different separation requirements. This analysis also examines how CNAs have evolved by introducing special properties that facilitate oil collection or make the adsorbent recyclable. We also discuss the difficulties in creating effective NAs for these important applications in a changing society, as well as the difficulties in creating oil recovery equipment for oil spill cleanup.

Different nanocellulose morphologies (cellulose nanofibers, nanocrystals and nanospheres) extracted from Sunn hemp (Crotalaria Juncea).

Nanocellulose of different morphologies was extracted from Sunn Hemp (Crotalaria Juncea) using acid hydrolysis. The work focused on two objectives: first, to valorize the Sunn Hemp fibers for nanocellulose (NC) production, and second, to study the effects of acid concentration on different morphologies of NC and their properties. The study extracted nanocellulose at five different concentrations of H2SO4: 16 %, 32 %, 48 %, 64 %, and 72 %. Obtained nanocellulose was characterized by Scanning Electron Microscopy (FE-SEM), Atomic Force Microscopy (AFM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and Thermogravimetric Analysis (TGA). AFM and FE-SEM confirmed the production of three different morphologies of nanocellulose. The NC-32 had a web-like structure typically observed for cellulose nanofibrils (CNF), whereas NC-48 and NC-64 were observed as cellulose nanocrystals (CNC) with rod-like and needle-like shapes, respectively, and NC-72 displayed spherical particles termed cellulose nanospheres (CNS). The total crystallinity index of NC was calculated using FTIR, and a similar trend of crystallinity was also observed from XRD analysis. NC-32 was obtained with the highest yield of 94.83 %, followed by 91.40 % and 81.70 % for NC-48 and NC-64, respectively, whereas NC-72 yielded the lowest yield of 12.03 %. NC-72 had the highest thermal stability among other NC morphologies.

Magnetically recoverable sol-gel auto-combustion developed Ni1-xCuxDyyFe2-yO4 magnetic nanoparticles for photocatalytic, electrocatalytic, and antibacterial applications.

Copper and dysprosium doped NiFe2O4 magnetic nanomaterials, Ni1-xCuxDyyFe2-yO4 (x = y = 0.00, 0.01, 0.02, 0.03), was prepared by utilizing sol-gel auto-combustion approach to inspect the photodegradation of methylene blue (MB) pollutant and also, to perform the electrocatalytic water splitting and antibacterial studies. The XRD analysis reveal the growth of a single-phase spinel cubic structure for produced nanomaterials. The magnetic traits show an increasing trend in saturation magnetization (Ms) from 40.71 to 47.90 emu/g along with a decreasing behaviour of coercivity from 158.09 to 156.34 Oe at lower and higher Cu and Dy doping content (x = 0.0-0.01). The study of optical band gap values of copper and dysprosium-doped nickel nanomaterials decreased from 1.71 to 1.52 eV. This will increase the photocatalytic degradation of methylene blue pollutant from 88.57% to 93.67% under natural sunlight, respectively. These findings clearly show that under natural sunlight irradiation for 60 min, the produced N4 photocatalyst displays the greatest photocatalytic activity with a maximum removal percentage of 93.67%. The electrocatalytic characteristics of produced magnetic nanomaterials for both HER and OER were examined with a Calomel electrode taking as a reference in a 0.5 N H2SO4 and 0.1 N KOH electrolyte. The N4 electrode demonstrated considerable 10 and 0.024 mA/cm2 of current density, with onset potentials of 0.99 and 1.5 V for HER and OER and also, have tafel slopes of 58.04 and 295 mV/dec, respectively. The antibacterial activity for produced magnetic nanomaterials was examined against various bacteria (Bacillus subtilis, Staphylococcus aureus, S. typhi, and P. aeruginosa) in which N3 sample produced significant inhibition zone against gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) but no zone of inhibition against gram-negative bacteria (S. typhi and P. aeruginosa). With all these superior traits, the produced magnetic nanomaterials are highly valuable for the wastewater remediation, hydrogen evolution, and biological applications.

Investigation of electrical transport properties in solution-processed Bi2Se3-AgMnOOH nanocomposite.

In this paper, we report the fundamental electrical transport properties measured in Bi2Se3-AgMnOOH nanocomposite disc, which is prepared for the first time by convenient low temperature solution-phase chemistry in conjunction with redox-mediated methodology. The comparative structural and morphological analyses for the nanocomposite with pristine Bi2Se3 are comprehensively investigated by different material characterization techniques. The results demonstrate the successful in situ composite fabrication between the Bi2Se3, Ag and γ-MnOOH components. Besides, the present work introduces a systematic approach for the examination of electrical transport properties in Ohmic and non-Ohmic regimes over a wide temperature range. The results from the room temperature transport measurement exhibited that the nanocomposite demonstrated non-linearity after a certain current I0 (onset current), whereas Bi2Se3 was linear in the entire measured current range. An enhancement of the conductance was observed for Bi2Se3-AgMnOOH compared to the pure Bi2Se3 material, which is credited to the composite effect. The onset exponents xT (DC conductance) and xf (AC conductance) with phase-sensitive character demonstrate different values below and above 180 K separating two different phases with different conduction mechanisms. Also, flicker noise analysis established the correlation between the DC conductance in terms of Ohmic to non-Ohmic transition after the onset voltage V0. This transition phenomenon from Ohmic to non-Ohmic behaviour is explained from the structural point of view of the nanocomposite. The present investigation highlights the importance of using the bottom-up solution-phase strategy for the synthesis of high quality Bi2Se3-based nanocomposites for transport studies and their possible future applications.

Insights into thermal degradation kinetics and liquid crystalline behavior of cellulose nanocrystals from the waste of Cajanus cajan (pigeon pea).

Cellulose nanocrystals (CNCs) are essential for advancing nanotechnology and modern science. This work used the Cajanus cajan stem, an agricultural waste, as a lignocellulosic mass, which can serve as a supply of CNCs. After extraction from the Cajanus cajan stem, CNCs have been thoroughly characterized. FTIR (Infrared Spectroscopy) and ssNMR (solid-state Nuclear Magnetic Resonance) successfully validated eliminating additional components from the waste stem. The ssNMR and XRD (X-ray diffraction) were utilized to compare the crystallinity index. For structural analysis, the XRD of cellulose Iß was simulated to compare with the extracted CNCs. Various mathematical models inferred thermal stability and its degradation kinetics to ensure its high-end applications. Surface analysis established the rod-like shape of the CNCs. Rheological measurements were performed to gauge the liquid crystalline properties of CNC. The anisotropic liquid crystalline CNCs' birefringence proves that the Cajanus cajan stem is a promising resource for making CNCs for cutting-edge applications.

Influence of graphene oxide on rheology, mechanical, dielectric, and triboelectric properties of poly(vinyl alcohol) nanocomposite hydrogels prepared via a facile one step process.

The present investigation aims to develop hydrogels with higher mechanical stability for triboelectric applications by adopting a simple method to fabricate a graphene oxide (GO) incorporated poly(vinyl alcohol) (PVA) nanocomposite hydrogel. Instead of the traditional repeated freeze-thaw method, high-shear solution mixing followed by solvent exchange with deionized water was adopted. Morphological observations showed dense and undulated microstructures in the nanocomposite hydrogel with increased GO concentration. Attenuated Total Reflection Fourier Transform Infrared spectroscopy confirmed a higher degree of intermolecular H-bonding between the hydroxyl group of PVA and oxygenated groups of GO, which leads to a robust gel formation. The formation of a robust PVA/GO nanocomposite hydrogel was examined through rheological investigations at room temperature. Nanoindentation analysis estimated a significant increase in hardness and Young's modulus of the nanocomposite hydrogels. Broadband dielectric spectroscopy showed the variation of the dielectric properties of the PVA/GO nanocomposite hydrogels with increased GO concentration. The PVA/GO nanocomposite hydrogels exhibited a maximum output voltage of 3.65 V at 0.075 wt% GO content during finger tapping experiment suggesting the potential for triboelectric applications. The extensive analysis demonstrates the influence of a very low concentration of GO on the variation of the morphology, rheology, mechanical, dielectric, and triboelectric properties of PVA/GO nanocomposite hydrogels.

Surfactant Assisted In Situ Synthesis of Nanofibrillated Cellulose/Polymethylsilsesquioxane Aerogel for Tuning Its Thermal Performance.

Nanofibrillated cellulose (NFC) and polymethylsilsesquioxane (PMSQ) based aerogel are prepared by the sol-gel method. The objective of this work is to study the impact of surfactant and base catalyst on the thermal and mechanical performance of the corresponding aerogel. The rheological premonitory assists in predicting the bulk properties of the aerogel. The chemical structure of the aerogel is studied by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and solid-state nuclear magnetic resonance (NMR). X-ray microtomographic (XMT) analysis confirms the homogeneous and monolithic structure of the aerogel. The lowest thermal conductivity is achieved as 23.21 mW m-1 K-1 with V-0 and HBF rating through UL-94 test. Thermal performance of aerogels is cross-verified through modeling and simulation in COMSOL multiphysics platform. The mechanical properties of aerogel are evaluated by monolithic compression test in axial and radial compression test up to 90% strain, cyclic compression loading-unloading, and reloading test, flexural test, and dynamic mechanical analysis. The time-temperature analysis has shown around 5 °C temperature difference in the middle of the room after using the aerogel panel at the exposed surface, which assists in the practical application of the synthesized aerogel panel.

Mechanically durable green aerogel composite based on agricultural lignocellulosic residue for organic liquids/oil sorption.

Various oil spill cleanup sorbents have good hydrophobicity and oil separation efficiency, but their practical use has been limited due to the difficult and costly fabrication procedure. The research aims towards material development using the consumption of lignocellulosic agricultural residue for isolating cellulose nanofiber and its forward use to construct a 3D porous structure. A simple freeze-drying technique was used to assemble low-density porous structure. The biodegradable polylactic acid coating was used to alter the wettability from hydrophilic to hydrophobic and the maximum water contact angle value was around 120°. The prepared coated samples were testified for a series of oil/organic solvents-water mixtures. The sorption capacity was in the range of 28-70 g/g. The prepared aerogels were efficiently reused for at least 10 cycles. Developed material was used in continuous oil-water separation to remove oil from the water's surface. The cost analysis was estimated for scaleup production in the future.

Advanced packaging for distribution and storage of COVID-19 vaccines: a review.

The outbreak of the coronavirus disease 2019 global pandemic (COVID-19) has affected billions of lives, posing critical challenges to the healthcare system, vaccine manufacturers, packaging scientists, and daily public activity. Biotechnological advances have allowed to create rapidly vaccines, yet the success of an efficient immunization mainly depends on the safe and timely delivery of vaccines. In particular, packaging plays a crucial role in protecting, preserving, transporting, and distributing vaccines. Here, we review advanced packaging for distribution and storage of COVID-19 vaccines, with focus on innovative hybrid packaging materials, cyclic olefin polymers with nanolayer glass, and vials for vaccines. We present vaccine packaging, auto-disable syringes, stoppers, and closures. We discuss the chronology of the packaging system, and the labeling of the vaccine packages, with emphasis on bar codes, quick response codes, vaccine vial monitors, anti-counterfeiting and traceability measures.

Isolation of cellulose nanocrystals from different waste bio-mass collating their liquid crystal ordering with morphological exploration.

Cellulose nanocrystals (CNCs) have been recognized as one of the most promising nanofillers in modern science and technology owing to their outstanding characteristics of renewability, biodegradability, excellent mechanical strength, and liquid crystalline behavior. Interestingly, these properties are dependent on their genetic and also on the isolation process. Therefore, this research aimed to unveil how the biological variations of cellulose can influence on the physical properties of the extracted CNCs. A standard optimized extraction process was adopted to isolate the CNCs from different sources. Extracted CNCs were compared through characterization tools, including Fourier Transformation Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetry Analysis (TGA), Dynamic Light Scattering (DLS), Field Emission Scanning Electron Microscopy (FE-SEM), Atomic Force Microscopy (AFM), and Polarized Optical Microscopy (POM). Different self-assembly patterns were observed for different CNCs, owing to their biological variations. The resultant nanocrystals displayed variable morphologies such as spherical, rod, and needle shape. The hydrodynamic diameter, crystallinity index, decomposition temperature, liquid crystallinity, and storage modulus were varied. Nanocrystals isolated from non-wood feedstock have shown a higher degree of polymerization of 108.2 and a high Crystllinity Index (C·I.) of 55.1%. The rod-like morphology with the liquid crystalline pattern was obtained at 3 wt% concentration for SCNC.

Modified tamarind kernel polysaccharide-based matrix alters neuro-keratinocyte cross-talk and serves as a suitable scaffold for skin tissue engineering.

Advanced technologies like skin tissue engineering are requisite of various disorders where artificially synthesized materials need to be used as a scaffold in vivo, which in turn can allow the formation of functional skin and epidermal layer with all biological sensory functions. In this work, we present a set of hydrogels which have been synthesized by the method utilizing radical polymerization of a natural polymer extracted from kernel of Tamarindus indica, commonly known as Tamarind Kernel Powder (TKP) modified by utilizing the monomer acrylic acid (AA) in different mole ratios. These materials are termed as TKP: AA hydrogels and characterized by Atomic Force Microscopy (AFM), surface charge, and particle size distribution using Dynamic Light Scattering measurements. These materials are biocompatible with mouse dermal fibroblasts (NIH- 3T3) and human skin keratinocytes (HaCaT), as confirmed by MTT and biocompatibility assays. These TKP: AA hydrogels do not induce unwanted ROS signaling as confirmed by mitochondrial functionality determined by DCFDA staining, Mitosox imaging, and measuring the ATP levels. We demonstrate that in the co-culture system, TKP: AA allows the establishment of proper neuro-keratinocyte contact formation, suggesting that this hydrogel can be suitable for developing skin with sensory functions. Skin corrosion analysis on SD rats confirms that TKP: AA is appropriate for in vivo applications as well. This is further confirmed by in vivo compatibility and toxicity studies, including hemocompatibility and histopathology of liver and kidney upon direct introduction of hydrogel into the body. We propose that TKP: AA (1: 5) offers a suitable surface for skin tissue engineering with sensory functions applicable in vitro, in vivo, and ex vivo. These findings may have broad biomedical and clinical importance.

TRPM8 channel inhibitor-encapsulated hydrogel as a tunable surface for bone tissue engineering.

A major limitation in the bio-medical sector is the availability of materials suitable for bone tissue engineering using stem cells and methodology converting the stochastic biological events towards definitive as well as efficient bio-mineralization. We show that osteoblasts and Bone Marrow-derived Mesenchymal Stem Cell Pools (BM-MSCP) express TRPM8, a Ca2+-ion channel critical for bone-mineralization. TRPM8 inhibition triggers up-regulation of key osteogenesis factors; and increases mineralization by osteoblasts. We utilized CMT:HEMA, a carbohydrate polymer-based hydrogel that has nanofiber-like structure suitable for optimum delivery of TRPM8-specific activators or inhibitors. This hydrogel is ideal for proper adhesion, growth, and differentiation of osteoblast cell lines, primary osteoblasts, and BM-MSCP. CMT:HEMA coated with AMTB (TRPM8 inhibitor) induces differentiation of BM-MSCP into osteoblasts and subsequent mineralization in a dose-dependent manner. Prolonged and optimum inhibition of TRPM8 by AMTB released from the gels results in upregulation of osteogenic markers. We propose that AMTB-coated CMT:HEMA can be used as a tunable surface for bone tissue engineering. These findings may have broad implications in different bio-medical sectors.

Bio-extract amalgamated sodium alginate-cellulose nanofibres based 3D-sponges with interpenetrating BioPU coating as potential wound care scaffolds.

In this work, sodium alginate (SA) based "all-natural" composite bio-sponges were designed for potential application as wound care scaffold. The composite bio-sponges were developed from the aqueous amalgamation of SA and cellulose nanofibres (CNFs) in bio-extracts like Rice water (Rw) and Giloy extract (Ge). These sponges were modified by employing a simple coating strategy using vegetable oil-based bio-polyurethane (BioPU) to tailor their physicochemical and biological properties so as to match the specific requirements of a wound care scaffold. Bio-sponges with shared interpenetrating polymeric network structures were attained at optimized BioPU coating formulation. The interpenetration of BioPU chains within the sponge construct resulted in the formation of numerous micro-networks in the interconnected microporous structure of sponges (porosity ≥75%). The coated sponge showed a superior mechanical strength (compressive strength ~3.8 MPa, compressive modulus ~35 MPa) with appreciable flexibility and recoverability under repeated compressive loading-unloading cycles. A tunable degradation behaviour was achieved by varying BioPU coating concentrations owing to the different degree of polymer chain entanglement within the sponge construct. The physical entanglement of BioPU chains with core structural components of sponge improved their structural stability by suppressing their full fragmentation in water-based medium without affecting its swelling behaviour (swelling ratio > 1000%). The coated sponge surface has provided a suitable moist-adherent physical environment to support the adhesion and growth of skin cells (HaCaT cells). The MTT (3-(4,5-dimethyl thiazolyl-2)-2,5-diphenyltetrazolium bromide) assay and hemolytic assay revealed the non-toxic and biocompatible nature of coated sponges in vitro. Moreover, no signs of skin erythema or edema were observed during in vivo dermal irritation and corrosion test performed on the skin of Sprague Dawley (SD) rats. Our initial observations revealed the credibility of these sponges as functional wound care scaffolds as well as its diverse potential as a suitable substrate for various tissue engineering applications.

Zener-like electrical transport in polyaniline-graphene oxide nanocomposites.

The present study includes the fabrication and characterization and an investigation of the electrical transport properties of nanocomposites of n-PANI and graphene oxide (GO). The samples were prepared by loading different weight percentages D of GO during the chemical oxidative in situ polymerization of aniline monomers. Structural characterization by XRD, FTIR, FESEM, etc. confirmed that the nanocomposites exhibited superior morphology and thermal stability. The transport properties were studied by measuring the variation of conductivity with temperature T, V-I characteristics and the fundamental response V f at different temperatures T. The dc conductance Σ showed a transition from insulator type behavior to weakly temperature dependent behavior at temperature T D, which decreased with increasing D. The V-I characteristics were generally nonlinear and the nonlinearity increased with decreasing temperature. Moreover, at temperatures T ≥ T D, the characteristics showed saturation of voltage for higher values of current, similar to Zener diodes. At lower temperatures (T ≤ T D), a voltage maximum occurred, similar to thyristors. This behavior leads to the possibility of fabricating devices containing these nanocomposites. We have tried to analyze these results using the framework of scaling theory and the concept of inter-chain hopping conduction and tunneling between conducting grains separated by insulating regimes in the nanocomposite.

Ferrocenyl palladacycles derived from unsymmetrical pincer-type ligands: evidence of Pd(0) nanoparticle generation during the Suzuki-Miyaura reaction and applications in the direct arylation of thiazoles and isoxazoles.

A new family of ferrocenyl-palladacycle complexes Pd(L1)Cl (Pd1) and Pd(L2)Cl (Pd2) were synthesized and characterized by UV-visible, IR, ESI-MS, and NMR spectral studies. The molecular structures of Pd1 and Pd2 were determined by X-ray crystallographic studies. Palladacycle catalyzed Suzuki-Miyaura cross-coupling reactions were investigated utilizing the derivatives of phenylboronic acids and substituted chlorobenzenes. Mechanistic investigation authenticated the generation of Pd(0) nanoparticles during the catalytic cycle and the nanoparticles were characterized by XPS, SEM and TEM analysis. Direct C-H arylation of thiazole and isoxazole derivatives employing these ferrocenyl-palladacycle complexes was examined. The reaction model for the arylation reaction implicating the in situ generation of Pd(0) nanoparticles was proposed.

Esterified superhydrophobic nanofibrillated cellulose based aerogel for oil spill treatment.

The present work aims towards the structuring of a physically cross-linked aerogels based on nanofibrillated cellulose (NFC) and polyvinyl alcohol (PVA), i.e., NFC/PVA aerogels for oil spillage cleanup. Highly porous (98%) NFC/PVA aerogels having both meso-micro pores were achieved by freeze drying technique. To impart super-hydrophobicity to the composite aerogel, a simple dip coating process was adopted using stearic acid chloride (SAC) solution. The SAC conjugated aerogels combined both superhydrophobic and oleophilic characteristics showed a contact angle of ∼159° and ∼0° with water and oil respectively. FESEM and X-ray microtomography images revealed a self-assembled 3D porous cellular structure of the aerogels. The prepared aerogels were found to be very efficient in separating a series of oil/water mixtures and various organic solvents with excellent selectivity and recyclability. Absorption capacity of the aerogels was at least 35 times higher than their dry weight. Simple mechanical squeezing method was adopted for repetitive uses.