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 pre‑carbonization and additional lignin extraction, reducing chemical usage and presenting a greener approach.

Highly conductive CNT aerogel synthesized via an inert FC-CVD technique: a step towards a greener approach

The accumulation of hydrogen gas molecules generated in situ as a byproduct of chemical reactions enhances the reducing ambient conditions of the otherwise inert FC-CVD reactor which improves the quality of the CNTs.

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 (X₂ = 0.254, Y₂ = 0.152 and X₃ = 0.233, Y₃ = 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.

Polyacrylonitrile/NaYF₄:Eu⁺³ nanophosphor composite nanofibers have been successfully prepared using the electrospinning technique.

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 (T_g) 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.

Highly purified CNTs: an exceedingly efficient catalyst support for PEM fuel cell

High performance in PEM fuel cells has been achieved using purified CNTs as catalyst support.

Excellent mechanical properties of carbon fiber semi-aligned electrospun carbon nanofiber hybrid polymer composites

The excellent mechanical properties of carbon fiber fabric hybrid polymer composites is achieved by integrating continuous semi-aligned carbon nanofiber layers in the interlaminar region between carbon fiber fabric plies.

Dynamic mechanical properties of multiwall carbon nanotube reinforced ABS composites and their correlation with entanglement density, adhesion, reinforcement and C factor

Herein, the dynamic mechanical properties of MWCNTs reinforced ABS composites have been studied using a DMA and the results have been correlated with entanglement density, adhesion, reinforcement and C Factor.

Fabrication of nanofiber stationary phases from chopped polyacrylonitrile co-polymer microfibers for use in ultrathin layer chromatography of amino acids

Polyacrylonitrile co-polymer microfibers of diameter 12.5 μm was used for electrospinning to produce nanofibers and then used as a stationary phase in UTLC for on-plate identification and separation of amino acid from drug sample.

Purification method dependent fluorescence from nitrogen-vacancy (NV) centers of nano-diamonds

Nanodiamonds purified through acid reflux and air oxidation methods shows difference in their water dispersibility, particle shape and fluorescence intensity deciding their selective preference for biophotonic and nanophotonic applications.

Graphene boosts thermoelectric performance of a Zintl phase compound

The nanocomposite of Mg₃Sb₂-based Zintl phase compound, fabricated by utilizing, GNS, as a nanocomposite additive, enhances significantly the thermoelectric performance.

Improved microwave absorption in lightweight resin-based carbon foam by decorating with magnetic and dielectric nanoparticles

Carbon foam (CFoam) decorated with Fe₃O₄–ZnO nanoparticles significantly improved electromagnetic radiation shielding effectiveness which is mainly dominated by absorption component.

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.