A Fluorescent Carbon Nanoparticle for Photodynamic Cell Therapy via Rapid Non-Endocytic Uptake.

Although photodynamic therapy is a promising approach for cancer treatment, it has limited clinical application due to the poor performance of conventional photosensitizers. In this study, we present a carbon nanoparticle-based photosensitizer for efficient photodynamic cell therapy. The nanoparticles have been synthesized from a steel industry-based waste material, exhibiting strong fluorescence in the visible region, rapidly entering the cell via non-endocytic uptake, and localizing within the mitochondria. Light exposure of nanoparticle-labeled cells offers efficient photodynamic therapy and induces cytotoxicity. Overall, this study highlights the utility of carbon nanoparticles in efficient photodynamic therapy via rapid cellular uptake and subcellular targeting.

Synthesis of an industrial by-product-based polymeric additive for use with non-coking coal in metallurgical coke making and a combined density functional theory assessment of its molecular mechanism in fluidity development.

Recently, the utilization of inferior grade coal for the production of fuel-based materials, i.e., metallurgical coke, is an exciting research area in the industrial sector because of the limited reserves of prime coking coal worldwide. In the steel industry, coal tar is the most abundant and sustainable cost-effective by-product, which is a source of an adequate amount of aromatic components such as phenol or its derivative with polycyclic aromatic hydrocarbons. Therefore, for the first time, we developed a novel organic polymeric additive through a cross-linking polymerization technique using a coal-tar precursor and paraformaldehyde monomer with a glycol-tetraline-based plasticizing agent and explored its application for use as inferior coal in metallurgical coke production. Our synthesized polymer was a homogeneous flowable liquid material; the synthesis process was simple, easily scalable with a high production yield (∼90%), and economical. The interaction of the polymeric additive with the coal matrix was investigated via TGA and H2 evolution study to understand the role of the polymer in coal carbonization. The polymeric additive has significantly improved the crucible swelling number (CSN), fluidity, and plastic layer thickness property of coal. In this connection, we also performed a computational study to rationalize the mechanism of action of the polymeric additive. Exploration of the reaction features through density functional theory calculations offered significant insight into the role of the polymer in assisting coal fluidity development. Addition of the polymer prominently enhanced the coke strength after reaction (CSR) of a non-coking coal enriched blend during carbonization. This study discloses new prospects in the steel industry for the sustainable and bulk scale synthesis of a coal tar-based polymeric additive for the profitable production of metallurgical coke.

Development of an auto-phase separable and reusable graphene oxide-potato starch based cross-linked bio-composite adsorbent for removal of methylene blue dye.

In this work, we report the development of a cross-linked bio-composite consisting of graphene oxide, potato starch, cross-linker glutaraldehyde and its application to adsorption of the industrial dye, methylene blue, from aqueous solution. The inexpensiveness, non-hazardous nature and easy bio-degradability are the major reasons for the selection of starch material as one of the components of the bio-composite. The bio-composite has been characterized by FTIR, SEM, XRD, particle size and zeta potential analysis. The FTIR analysis reveals the nature of the binding sites and surface morphology of the bio-composite can be understood through SEM. The auto-phase separability of the adsorbent i.e., the precipitation of the adsorbent without any mechanical means is another factor which makes this particular material very attractive as an adsorbent. Parameters like adsorbent dosage, pH, temperature, rotation speed and salt concentration have been varied to find out the suitable dye adsorption conditions. Furthermore, the time dependence of adsorption process has been analyzed using pseudo-first and pseudo-second order kinetics. The adsorption isotherms have been constructed to suggest convincing mechanistic pathway for this adsorption process. Finally, desorption studies have been successfully performed in 3 cycles, establishing the reusability of the material, which should allow the adsorbent to be economically promising for practical application in wastewater treatment.

Anionically functionalized guar gum embedded with silica nanoparticles: An efficient nanocomposite adsorbent for rapid adsorptive removal of toxic cationic dyes and metal ions.

In the present work, a novel biodegradable nanocomposite has been developed (h-GG/SiO2) based on anionically modified guar gum and in-situ deposited SiO2 NPs through sol-gel technique. Here the anionically modified guar gum stimulates the silica polymerization process and hence acts as a unique template for the development of spherical SiO2 NPs. Batch adsorption studies indicate that h-GG/SiO2 nanocomposite shows remarkable adsorption capacity for cationic dyes/metal ions (Qmax: 781.25mgg-1for malachite green (MG), 281.69mgg-1 for safranin (SF); 645.16mgg-1 for Pb2+, 709.21mgg-1 for Cd2+) as well as it efficiently and selectively removes cationic MG from mixture of dye solutions. Finally the worthy regenerative efficacy of h-GG/SiO2 facilitates the adsorbent to be economically promising for practical application in the field of wastewater management.

Selective removal of toxic anionic dyes using a novel nanocomposite derived from cationically modified guar gum and silica nanoparticles.

A novel nanocomposite derived from cationically modified guar gum and in-situ incorporated SiO2 NP (cat-GG/SiO2) has been developed. The cat-GG has been synthesised by grafting poly(2-(diethylamino)ethyl methacrylate) on GG backbone. Various analyses endorse the suitability of cat-GG as well-organized template for the development of homogeneous SiO2 NPs. Dye adsorption studies predict that cat-GG/SiO2 efficiently and selectively adsorb anionic dyes (reactive blue-RB and Congo red-CR) from mixture of dye solutions. This is because of high surface area, multifunctional chelating H-bonding interactions and electrostatic interactions of cationic adsorbent with anionic dyes. Dyes adsorbed on the composite surface are desorbed reversibly using pH 10 stripping solution. Besides, cat-GG/SiO2 has been recycled efficiently with no prominent loss of dye uptake capacity, even after 4 adsorption-desorption cycles.

Efficient and rapid adsorption characteristics of templating modified guar gum and silica nanocomposite toward removal of toxic reactive blue and Congo red dyes.

The present study highlights the potentiality of sol-gel synthesized guar gum-graft-poly (acrylamide)/silica (g-GG/SiO2) hybrid nanocomposite toward the rapid removal of toxic reactive blue 4 (RB) and Congo red (CR) dyes from aqueous solution. Various physicochemical characterizations support the feasibility of the functionalized guar gum matrix as efficient template for the formation of homogeneous nanoscale silica particles. The composite demonstrates rapid and superior adsorption efficiency of RB (Qmax: 579.01 mg g(-1) within 40 min) and CR (Qmax: 233.24 mg g(-1) within 30 min) dyes from aqueous environment. Here, the pH driven adsorption process depends strongly on the ionic strength of the salt solution. The adsorption kinetics data predicts that pseudo second-order (surface adsorption) and intraparticle diffusion take place simultaneously. The adsorption equilibrium is in good agreement with the Langmuir isotherm, while the thermodynamics study confirms spontaneous nature of the adsorption process. Desorption study predicts the excellent regenerative efficacy of nanocomposite.

Modified amylopectin based flocculant for the treatment of synthetic effluent and industrial wastewaters.

Herein, we report the application of an efficient polymeric flocculant based on amylopectin grafted with poly (acrylic acid) (g-AP) for the treatment of synthetic effluent as well as various industrial wastewaters. The flocculation characteristics of g-AP have been explored in different pH conditions using silica suspension by measurement of residual turbidity as well as floc size. Results suggest that in acidic pH, patching mechanism is predominating while at neutral and alkaline pH, bridging is the main mechanism. In addition, aggregation of particles and particle collision models confirm that bridging mechanism is the key mechanism at alkaline condition. Further, g-AP demonstrates excellent potential as flocculant for the treatment of paper effluent, textile wastewater and shows better flocculation performance than that of commercially available flocculant. Besides, the pilot scale study of mine processwater suggests excellent efficacy of g-AP as flocculant.

Rapid adsorptive removal of toxic Pb(2+) ion from aqueous solution using recyclable, biodegradable nanocomposite derived from templated partially hydrolyzed xanthan gum and nanosilica.

This work studied the application of a novel biodegradable nanocomposite based on partially hydrolyzed polyacrylamide grafted xanthan gum and nanosilica (h-XG/SiO2) towards efficient and rapid removal of toxic Pb(2+) ions from aqueous environment. The uptake ability of Pb(2+) using h-XG/SiO2 has been studied in batch adsorption experiments with variation of adsorption parameters. The excellent removal rate (99.54% adsorption within 25min) and superior adsorption capacity (Qmax=1012.15mgg(-1)) of the composite material have been explained on the basis of synergistic and chelating effects of h-XG/SiO2 with Pb(2+) ion through electrostatic interactions. The kinetics, isotherm and thermodynamics studies reveal that Pb(2+) adsorb rapidly on nanocomposite surface, which is in agreement with pseudo-second-order kinetics and Langmuir adsorption isotherm models. In consequence of excellent adsorption as well as regeneration characteristics of nanocomposite, it has been found to be a promising adsorbent towards removal of Pb(2+) ions from battery industry wastewater.

Efficient removal of malachite green dye using biodegradable graft copolymer derived from amylopectin and poly(acrylic acid).

This article reports on the application of a high performance biodegradable adsorbent based on amylopectin and poly(acrylic acid) (AP-g-PAA) for removal of toxic malachite green dye (MG) from aqueous solution. The graft copolymer has been synthesized and characterized using various techniques including FTIR, GPC, SEM and XRD analyses. Biodegradation study suggests that the co-polymer is biodegradable in nature. The adsorbent shows excellent potential (Qmax, 352.11 mg g(-1); 99.05% of MG has been removed within 30 min) for removal of MG from aqueous solution. It has been observed that point to zero charge (pzc) of graft copolymer plays significant role in adsorption efficacy. The adsorption kinetics and isotherm follow pseudo-second order and Langmuir isotherm models, respectively. Thermodynamics parameters suggest that the process of dye uptake is spontaneous. Finally desorption study shows excellent regeneration efficiency of adsorbent.

Enhanced removal of methylene blue and methyl violet dyes from aqueous solution using a nanocomposite of hydrolyzed polyacrylamide grafted xanthan gum and incorporated nanosilica.

The synthesis and characterization of a novel nanocomposite is reported that was developed as an efficient adsorbent for the removal of toxic methylene blue (MB) and methyl violet (MV) from aqueous solution. The nanocomposite comprises hydrolyzed polyacrylamide grafted onto xanthan gum as well as incorporated nanosilica. The synthesis exploits the saponification of the grafted polyacrylamide and the in situ formation of nanoscale SiO2 by a sol-gel reaction, in which the biopolymer matrix promotes the silica polymerization and therefore acts as a novel template for nanosilica formation. The detailed investigation of the kinetics and the adsorption isotherms of MB and MV from aqueous solution showed that the dyes adsorb rapidly, in accordance with a pseudo-second-order kinetics and a Langmuir adsorption isotherm. The entropy driven process was furthermore found to strongly depend on the point of zero charge (pzc) of the adsorbent. The remarkably high adsorption capacity of dyes on the nanocomposites (efficiency of MB removal, 99.4%; maximum specific removal Qmax, 497.5 mg g(-1); and efficiency of MV removal, 99.1%; Qmax, 378.8 mg g(-1)) is rationalized on the basis of H-bonding interactions as well as dipole-dipole and electrostatic interactions between anionic adsorbent and cationic dye molecules. Because of the excellent regeneration capacity the nanocomposites are considered interesting materials for the uptake of, for instance, toxic dyes from wastewater.

Effective removal of Congo red dye from aqueous solution using modified xanthan gum/silica hybrid nanocomposite as adsorbent.

The aim of this work is to study the feasibility of XG-g-PAM/SiO2 nanocomposite towards its potential application as high performance adsorbent for removal of Congo red (CR) dye from aqueous solution. The surface area, average pore size and total pore volume of the developed nanocomposite has been determined. The efficiency of CR dye adsorption depends on various factors like pH, temperature of the solution, equilibrium time of adsorption, agitation speed, initial concentration of dye and adsorbent dosage. It has been observed that the nanocomposite is having excellent CR dye adsorption capacity (Q0=209.205 mg g(-1)), which is considerably high. The dye adsorption process is controlled by pseudo-second order and intraparticle diffusion kinetic models. The adsorption equilibrium data correlates well with Langmuir isotherm. Desorption study indicates the efficient regeneration ability of the dye loaded nanocomposite.

Amphoteric amylopectin: a novel polymeric flocculant.

Novel flocculant based on amphoteric amylopectin for wastewater and industrial effluents treatment has been developed in authors' laboratory. Amphoteric flocculants have anionic and cationic moieties on the same macromolecule and is used to remove both positively and negatively charged contaminant particles in suspensions. Amylopectin based flocculants have been found to be highly efficient flocculant and hence it has been chosen as base polysaccharide. By grafting of polyacrylamide and subsequent hydrolysis, anionic amylopectin has been synthesized. Afterwards, a cationic moiety has been inserted both by chemical/microwave processing. The flocculation efficiency of the amphoteric amylopectin has been tested in kaolin and iron ore suspensions. The results indicate its high efficiency in comparison with anionic, grafted, and base amylopectin. The amphoteric amylopectin prepared via microwave irradiation showed best flocculation efficiency.

Novel biodegradable nanocomposite based on XG-g-PAM/SiO2: application of an efficient adsorbent for Pb2+ ions from aqueous solution.

This article highlights the development of a novel nanocomposite based on nanosilica filled modified natural polymer (i.e. xanthan gum grafted with polyacrylamide:XG-g-PAM) for removal of Pb(2+) ions from aqueous solution. The chemical, structural, textural, and rheological characteristics of the nanocomposite (XG-g-PAM/SiO(2)) revealed stronger interaction of silica nanoparticles with polymer matrix and showed maximum adsorption capacity (Q(max)=537.634 mg g(-1)) of Pb(2+) ion, which is significantly higher than other reported adsorbents. This developed novel material also finds potential application as an efficient adsorbent for the treatment of battery industry wastewater. The enhanced adsorption efficiency may be because of its higher hydrodynamic radius and hydrodynamic volume. The adsorption kinetic parameters were best described by pseudo-second-order model. The adsorption equilibrium data fitted well with Langmuir isotherm. The thermodynamic studies confirm that the adsorption is spontaneous and endothermic. Desorption studies affirmed the regenerative efficacy of loaded Pb(2+).