Direct conversion of lignin-rich black liquor to activated carbon for supercapacitor electrodes.

The escalating industrialization trend underscores the imperative for sustainable waste management practices. The present investigation explores a sustainable methodology for managing the waste generated from the kraft process by directly converting it into activated carbon (BLAC) through a cost-effective hydrothermal-assisted activation method. The research involved a comparative analysis of BLAC with acid-washed black liquor lignin-derived activated carbon (ABLAC) and commercial lignin-derived activated carbon (SALAC). The analysis revealed that BLAC possesses a well-developed micro and mesoporous structure, yielding a significantly higher surface area of 2277.2 m2/g as compared to ABLAC (1260 m2/g) and SALAC (1558.4 m2/g). The presence of inherent alkali in the black liquor is the main factor influencing the surface area of the BLAC. Furthermore, it demonstrated impressive electrochemical performance, showing a specific capacitance value of 871.4 F/g at 1 A/g current density, positioning it as a formidable electrode material for supercapacitor applications. The proposed direct conversion strategy will eliminate the need for high-temperature pre­carbonization and additional lignin extraction, reducing chemical usage and presenting a greener approach.

Carbon nanotube incorporated eucalyptus derived activated carbon-based novel adsorbent for efficient removal of methylene blue and eosin yellow dyes.

Carbon nanotube (CNT) incorporated eucalyptus derived activated carbon-based novel adsorbent is synthesized by a novel route. This adsorbent is investigated for the removal of two different dyes; methylene blue (MB) and eosin yellow (EY) from the waste water. The effect of pH, adsorbent dose, contact time and initial concentration, has been used to measure the dye removal efficiency of the adsorbent. Langmuir isotherm, Freundlich isotherm and D-R isotherm models were used to fit the experimental dye adsorption data, with the D-R model providing the best fit. The maximum adsorption efficiency of adsorbent for MB and EY removal is 49.61 and 49.15 mg/g, respectively. Reaction kinetics studies were also established to further investigate the dye adsorption mechanism. It is observed that pseudo second order model define the reaction kinetics involved in the reaction. This activated carbon adsorbent based on CNTs is shown to be highly promising for water decontamination applications.

Trimetallic composite nanofibers for antibacterial and photocatalytic dye degradation of mixed dye water.

Membrane technology is an advanced approach to making a healthier and cleaner environment. Using such catalytic membrane technology to get clean, usable water by removal of dye impurities as well as pathogenic microbes is the main goal behind the research work. Here, we present the synthesis and efficacy study of polymethyl methacrylate (PMMA)-based Ag/ZnO/TiO2 trimetallic bifunctional nanofibers with antibacterial and photocatalytic activity. The nanofibers have been proven to be effective for the degradation of methylene blue (MB 93.4%), rhodamine B (Rh 34.6%), auramine-O (Au 65.0%) and fuchsin basic (FB 69.8%) dyes individually within 90 min in daylight. The study is further extended in abating a mixture of these dyes from contaminated water using composite nanofibers. Also, in the case of a mixture of these dyes (3 ppm each), nanofibers show dye degradation efficiency (DDE) of 90.9% (MB), 62.4% (Au) and 90.3% (FB and Rh) in 60 min. The role of Ag nanoparticles with a synergic photocatalytic effect on ZnO and TiO2 is also demonstrated. Also, PMMA/ZnO/TiO2 composite fiber membrane in synergy with silver particles shows better antibacterial activity against Gram-negative bacteria E. coli, making PMMA/Ag/ZnO/TiO2 fibers a promising candidate in water purification.

A novel fabrication of electrospun polyacrylonitrile/NaYF4:Eu+3 light emitting nanofibers.

Polyacrylonitrile/NaYF4:Eu+3 nanophosphor composite nanofibers have been successfully prepared using the electrospinning technique. The electrospun nanofibers exhibited intense emission of gradient blue (X 2 = 0.254, Y 2 = 0.152 and X 3 = 0.233, Y 3 = 0.139) with different concentrations of nanophosphor under the excitation wavelength of 239 nm. The morphological and structural characterization of the nanofibers confirms the uniform dispersion of nanophosphor, while photoluminescence spectroscopy confirms tunability in luminescence properties.

Improved thermomechanical and electrical properties of reduced graphene oxide reinforced polyaniline - dodecylbenzenesulfonic acid/divinylbenzene nanocomposites.

HYPOTHESIS: Various efforts are going on to improve the electrical properties of carbon fiber reinforced polymer (CFRP) composites. Conducting polymer is one the promising material to achieve the desired electrical properties of CFRP composites without compromising the mechanical properties as a lighting sticking material. EXPERIMENTS: In present study, in addition to conducting polymer polyaniline (PANI), another conducting phase reduced graphene oxide (RGO) was incorporated in PANI based system. The RGO was synthesized and incorporated in different weight (0-0.5 wt%) fraction in dodecylbenzenesulfonic acid (DBSA) doped PANI-divinylbenzene (DVB) polymer to get PANI-DBSA/DVB nanocomposite. The mechanical and interfacial interaction was analyzed by universal testing machine (UTM) and transmitted electron microscopy (TEM). FINDINGS: The addition of optimum 0.3 wt% RGO improved flexural strength and modulus of PANI-DSBA/RGO-DVB composite by 153% and 32% respectively over neat PANI-DBSA/DVB nanocomposite. The maximum electrical conductivity 0.301 S/cm, glass transition temperature (Tg) and thermal stability of nanocomposite realized at 0.3 wt% of RGO. Raman spectroscopy and HRTEM confirmed the improvement of interfacial bonding by H-bonding and π-π interaction. For the 1st time we are reporting RGO utilisation for the improvement of thermomechanical and electrical interfacial properties of PANI-DBSA/DVB nanocomposite for the structural applications.

In vivo wound healing performance of drug loaded electrospun composite nanofibers transdermal patch.

Acute injuries or wound is required the fast delivery of drug to control infections without any side effect. In this direction in the present investigation, antibiotic ciprofloxacin loaded hydrophilic biodegradable poly vinyl alcohol (PVA) and sodium alginate (NaAlg) electrospun composite nanofiber based transdermal patch was developed for local delivery of antibiotic drug. The antibiotic drug ciprofloxacin was loaded in it by active loading. The drug entrapped in the composite nanofibers was confirmed by the scanning electron microscopy and swelling behavior. The in vivo studies were carried on male rabbits by using the drug loaded and unloaded composite nanofibers transdermal patch and marketed one. It is observed that, in vitro activity provides a sustained and controlled release pattern of the drug from transdermal patch. The mechanism of drug release was also studied using different models. The nanofiber transdermal patch follows the Higuchi and Korsmeyer-Peppas model for drug release. The in vivo studies demonstrate that, wound healing takes place in less time as compared drug unloaded patch. Hydroxyproline produced in wound bed with time shows that it content is maximum in case drug loaded PAV-NaAlg patch. This demonstrates that wound healing rate is higher in case drug loaded PVA-NaAlg transdermal patch.

Electrospun composite nanofiber-based transmucosal patch for anti-diabetic drug delivery.

The intention of the present investigation was to develop an oral formulation for an anti-diabetic drug that not only could deliver it in the active form but also provide a sustained and controlled release profile. A biodegradable poly(vinyl alcohol) (PVA) and sodium alginate (NaAlg) electrospun composite nanofiber based transmucosal patch was developed and the anti-diabetic drug insulin was loaded in it by active loading. The drug entrapment in the composite nanofibers during the processing was confirmed by scanning electron microscopy, atomic force microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The in vivo studies were carried on male Wistar rats by the sublingual route. The mucoadhesive strength results confirmed that the drug loaded PVA-NaAlg nanofiber patch had the highest strength among the PVA, PVA-NaAlg and drug loaded PVA-NaAlg samples, due to its higher water holding capacity. The in vitro activity provided a sustained and controlled release pattern of the drug from the nanofiber patch. In vivo activity validated the fact that insulin was delivered in its active state and showed appreciable results when compared to the commercial formulation. The insulin release follows first order kinetics followed by an initial burst release necessary to produce the desired therapeutic activity. Furthermore an encapsulation efficacy of 99% of the experimental formulation provides sufficient indication that the composite nanofibers serve as an ideal carrier for the delivery of insulin via the sublingual route. Thus the present investigation gives impetus to work in the direction of delivering anti-diabetic drugs (proteins and peptides) via the oral route using electrospun composite nanofiber transmucosal patches.