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1.
Int J Biol Macromol ; 268(Pt 2): 131762, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38657925

RESUMO

The present investigation describes the development of a novel Chitosan/Polyvinyl Alcohol/Montmorillonite Clay (CS/PVA/MMT) scaffold by adopting an electrospinning method, and their biocompatibility was evaluated in vitro with L929 fibroblast cell line to ascertain its use in wound healing applications. The fabricated scaffold was characterized using analytical techniques. FT-IR measurement exhibited the existence of relevant functional groups and XRD implies scaffolds' amorphous nature. The scaffold's morphology and pore diameter were assessed using TEM and SEM. The pore diameter of the as-prepared scaffold was approximately 125 nm. The antimicrobial assay of the scaffold was evaluated against selected pathogens which demonstrated higher antimicrobial efficacy. The scavenging activity tested using the DPPH assay showed remarkable scavenging capability. The wound healing properties were tested through the Cytotoxicity assay conducted on the L929 assay which proved the scaffold to be a suitable material for cell proliferation. Also, a Molecular docking investigation was carried out for CS/PVA/MMT ligand using human neutrophil elastase (HNE) 1H1B protein as a receptor in the CB-Dock server. Studies conducted in silico revealed strong interaction and high binding energy ratings of CS/PVA/MMT ligand with key residues of human neutrophil elastase (HNE) 1H1B proteins that help in tissue regeneration activity.


Assuntos
Bentonita , Proliferação de Células , Quitosana , Simulação de Acoplamento Molecular , Álcool de Polivinil , Alicerces Teciduais , Álcool de Polivinil/química , Quitosana/química , Quitosana/farmacologia , Bentonita/química , Bentonita/farmacologia , Proliferação de Células/efeitos dos fármacos , Alicerces Teciduais/química , Linhagem Celular , Camundongos , Animais , Humanos , Pele/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Regeneração/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Argila/química , Engenharia Tecidual/métodos
2.
Environ Res ; 204(Pt B): 112047, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34529967

RESUMO

Development of novel bionanomaterials for water and wastewater treatment has gained increased attraction and attention in recent times. The present study reports an effective biocomposite-based nano-photocatalyst comprised of nanochitosan (NCS), carboxymethyl cellulose (CMC), and titanium dioxide (TiO2) synthesized by sol-gel technique. The as-prepared NCS/CMC/TiO2 photocatalyst was systematically characterized by X-ray diffraction, Fourier Transform Infrared spectroscopy, Scanning Electron Microscopy with energy dispersive X-beam spectroscopy, Differential scanning calorimetry (DSC), and Thermogravimetric analysis (TGA). Photocatalytic degradation of the crystal violet (CV) dye using this nano photocatalyst was studied by varying the irradiation time, catalyst dosage, feed pH, and initial dye concentration. Further, the kinetic analysis of dye degradation was explored using the Langmuir-Hinshelwood model, and a plausible photocatalytic mechanism was proposed. The modification of TiO2 using NCS and CMC accelerated photocurrent transport by increasing the number of photogenerated electrons and holes. Overall, the study indicated the excellent photocatalytic performance of 95% CV dye degradation by NCS/CMC/TiO2 than the bare inorganic TiO2 photocatalyst under visible light irradiation.


Assuntos
Carboximetilcelulose Sódica , Violeta Genciana , Catálise , Cinética , Luz , Titânio , Difração de Raios X
3.
Chemosphere ; 271: 129426, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33482524

RESUMO

Biochar, created from Prosopis Juliflora (B-PJ) through an ionic polymerization route, was utilized as a sorbent to remediate turquoise blue (TB). The biochar was described utilizing Fourier change infrared spectroscopy. The effects of operating factors such as flow rate, bed depth, concentration, and solution pH were investigated in column mode. Thomas, Yoon-Nelson, and Adams-Bohart models were applied to examine the experimental column data and the correlation between operating factors. The greatest adsorption limit of the BPJ was discovered utilizing 200 mg/L of the adsorbate, B-PJ portion 3 g, at a contact time of 150 min and pH of 6. The adsorption energy and harmony isotherms were all around spoken to by the pseudo-second-request model and the Langmuir model, separately. The most extreme adsorption limit acquired from the Langmuir isotherm model was 0.005173 mg/g. The test energy information dissected utilizing various models featured that the pseudo-second request motor model created a prevalent depiction of the trial information. The adsorption energy followed a pseudo-second-request active model with high connection coefficients (R2 ˃0.98). These outcomes showed that alginate immobilized biochar is earth well-disposed locally accessible, powerful and practical adsorbent for the expulsion of TB color from modern wastewaters.


Assuntos
Prosopis , Poluentes Químicos da Água , Purificação da Água , Adsorção , Carvão Vegetal , Concentração de Íons de Hidrogênio , Cinética , Compostos Orgânicos , Poluentes Químicos da Água/análise
4.
Int J Biol Macromol ; 164: 1809-1824, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32750480

RESUMO

The aim of the present work was to evaluate the performance of polypropylene (PP)/sisal fiber (SF)/banana fiber (BF) and chitosan-based hybrid (chitosan(CS)/SF)/BF) composite materials for the adsorptive removal of cadmium (Cd) ions from water waste. Polypropylene is harnessed for its importance in forming strong composite materials for various applications. Chitosan biopolymer encloses a great deal of amino and hydroxyl groups, which provide effective removal of Cd ions from wastewater. The batch adsorption studies proved that the removal of Cd ions was pH-dependent and attained optimum at pH 5.5 for both the composites. Langmuir and Freundlich models were applied for the obtained experimental values. Based on the R2 values, it was evidenced that the adsorption process was best fitted with the Freundlich isotherm than Langmuir. The sorption capacity of CS/SF/BF hybrid composite (Cmax = 419 mg/g) is higher than PP/SF/BF composite (Cmax = 304 mg/g), and allows multilayer adsorption. Kinetics studies revealed that the pseudo-second-order model was followed during the removal of Cd ion from wastewater. The overall evaluation proved that though both the adsorbents are suitable for the removal of Cd ions, the efficiency of CS-based ternary composite material is better than PP-based composite.


Assuntos
Cádmio/isolamento & purificação , Quitosana/química , Polipropilenos/química , Purificação da Água/métodos , Adsorção , Biopolímeros/química , Cádmio/análise , Cádmio/toxicidade , Intoxicação por Metais Pesados , Concentração de Íons de Hidrogênio , Íons , Cinética , Musa/química , Nanocompostos , Águas Residuárias , Poluentes Químicos da Água/análise
5.
Int J Biol Macromol ; 104(Pt B): 1495-1508, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28472686

RESUMO

In the present work, the maleic anhydride and methacrylic acid monomers were grafted one after another onto chitosan by using ceric ammonium nitrate as the initiator. The optimum conditions for grafting were studied by varying the initiator concentration, monomer concentration and reaction temperature. The synthesized grafted samples were subjected to various analytical techniques such as FTIR, XRD, TGA and DSC methods The proof of formation of graft copolymer was ascertained from the results of FTIR analysis and XRD studies. The TGA and DSC results conclude the highly thermally stable behavior of the prepared graft copolymer sample. The prepared graft copolymer was utilized for removing copper and lead from aqueous solutions and optimum adsorption parameters were evaluated under various pH, adsorbent dose, contact time and initial metal ion concentration. The adsorption and kinetic studies have been explained by Langmuir, Freundlich and pseudo - first order, second order and intra particle diffusion models. From the results, it was seen that Freundlich isotherm was best fit in the case of adsorption studies which followed pseudo second order kinetics. The obtained results showed that the chitosan-g-maleic anhydride-g-methacrylic acid copolymer was very efficient in removing the heavy metals copper and lead from aqueous solution.


Assuntos
Quitosana/química , Cobre/química , Cobre/isolamento & purificação , Chumbo/química , Chumbo/isolamento & purificação , Anidridos Maleicos/química , Metacrilatos/química , Poluentes Ambientais/química , Poluentes Ambientais/isolamento & purificação , Cinética , Polímeros/química
6.
Int J Biol Macromol ; 104(Pt B): 1483-1494, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28472685

RESUMO

The feasibility of adsorption and desorption behavior of nanochitosan(NCS)/sodium alginate(SA)/microcrystalline cellulose (MC) bead prepared in 2:8:1 ratio for Pb(II) removal has been investigated through batch studies. The proof of adsorption of Pb(II) ions onto NCS/SA/MC beads was identified from FT-IR and EDX-SEM Studies. Studies of the effect of pH, adsorbent dose, metal ion concentration and temperature reveals that the optimum conditions for adsorption was found to be pH:6; adsorbent dose:4g; initial metal concentration: 62.5mg/L and temperature:50°C. Various equilibrium adsorption isotherm models namely Langmuir, Freundlich, Temkin and D-R applied for the analysis of isotherm data indicate that the Freundlich adsorption isotherm model was found to be followed. On the basis of kinetic studies, specific rate constants involved in the processes were calculated and the observed result shows that the pseudo second order kinetics was found to be a better fit. The desorption studies reveals that the recovery of Pb(II) from NCS/SA/MC bead was found to be effective by using 0.1M HCl solution. From the results it was evident that the NCS/SA/MC bead showed better Pb(II) uptake performance and regeneration for further use and hence it was found to be an efficient biosorbent for treating industrial effluent.


Assuntos
Alginatos/química , Celulose/química , Quitosana/química , Chumbo/química , Chumbo/isolamento & purificação , Purificação da Água/métodos , Água/química , Adsorção , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Concentração de Íons de Hidrogênio , Cinética , Microesferas , Nanoestruturas , Tamanho da Partícula , Soluções , Temperatura , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
7.
Int J Biol Macromol ; 104(Pt B): 1459-1468, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28551438

RESUMO

Removal of heavy metals from wastewater is essential to avoid water pollution. In the present study, the performance of Chitosan and Alginate nanocomposites was evaluated for the removal of chromium (VI) from water waste. The physicochemically characterized (FT-IR, XRD, SEM, DSC, and DLS) for wastewater treatment were studied. Batch adsorption experiments were performed to examine the removal process under various factors like the effects of initial concentration, adsorbent dose, pH, and agitation time. The metal ion removal was pH dependent and reached optimum at pH 5.0. Experimental data were analyzed by Langmuir and Freundlich adsorption isotherms. The isotherm study revealed that the adsorption equilibrium is well-fitted to the Freundlich isotherm and the sorption capacity of Chitosan and Alginate nanocomposites is very high, and the adsorbent favors multilayer adsorption. Pseudo-first- and -second-order kinetics models were used for describing kinetic data. It was determined that removal of Cr (VI) be well-fitted by second-order reaction kinetics. From the results, it was concluded that Chitosan and Alginate Nanocomposites is an excellent material as a biosorbent for Cr(VI) from water waste.


Assuntos
Alginatos/química , Quitosana/química , Cromo/química , Cromo/isolamento & purificação , Nanocompostos/química , Purificação da Água/métodos , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
8.
Int J Biol Macromol ; 104(Pt B): 1820-1832, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28185930

RESUMO

In this study, the anticancer drug letrozole (LTZ) was formulated using chitosan nanoparticles (CS-NPs) with the crosslinking agent sodium tripolyphosphate (TPP). The nano-formulation was optimized by varying the concentration of drug. The prepared particles were characterized using FTIR, TGA, XRD, SEM, TEM and DLS. From the FTIR results, the appearance of a new peak for CH, CC and CN confirms the formation of LTZ loaded chitosan nanoparticles. TEM images shows that the average particle size was in the range of 60-80nm and 20-40mm air dried and freeze dried samples respectively. Also the prepared formulation had been evaluated in vitro for determining its hemocompatability, biodegradability and serum stability. The preliminary studies supported that the chitosan nanoparticles formulation has biocompatibility and hemocompatible properties and it can act as an effective pharmaceutical excipient for letrozole.


Assuntos
Quitosana/química , Composição de Medicamentos , Íons/química , Nanopartículas/química , Nitrilas/química , Triazóis/química , Materiais Biocompatíveis , Portadores de Fármacos , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Humanos , Ligação de Hidrogênio , Cinética , Letrozol , Teste de Materiais , Estrutura Molecular , Nanopartículas/ultraestrutura , Nitrilas/administração & dosagem , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Triazóis/administração & dosagem , Difração de Raios X
9.
Int J Biol Macromol ; 104(Pt B): 1578-1585, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28174087

RESUMO

The present work was designed to remove toxic metals chromium and copper using the double grafted copolymer Chitosan-g-Maleic anhydride-g-ethylene dimethacrylate. The graft copolymer was synthesized through chain polymerization reaction using ceric ammonium nitrate as the initiator. Prepared Chitosan-g-Maleic anhydride-g-ethylene dimethacrylate was used in order to remove the heavy metals chromium and copper from aqueous solutions of 200ppm/L concentration proceeding batch adsorption process by varying the parameters such as adsorbent dose, contact time, pH and initial concentration of the metal solution. The experimental data were equipped with isotherm models such as Langmuir and Freundlich and pseudo-first order and pseudo-second order kinetics. The calculated results revealed that the adsorption favours Freundlich isotherm and follows pseudo-second order kinetics.


Assuntos
Quitosana/química , Cromo/química , Cromo/isolamento & purificação , Cobre/química , Cobre/isolamento & purificação , Malatos/química , Metacrilatos/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água
10.
Int J Biol Macromol ; 87: 545-54, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26952703

RESUMO

The present work deals with the preparation of the novel sorbent, glutaraldehye crosslinked silica gel/chitosan-g-poly(butyl acrylate) (Cs-g-PBA/SG) nanocomposite by sol-gel method for removal of toxic chromium ion. Prepared nanosorbent was then characterized by FTIR, XRD, DLS, SEM, BET isotherm for its formation and suitability. Its sorption capacity and sorption isotherms were brought under batch mode to suit the optimal parameters viz., contact time, pH, adsorbent dose and initial metal ion concentration which influence the sorption. The theoretical modeling such as Langmuir and Freundlich isotherm adsorption were applied to describe isotherm constants. Equilibrium data agreed well with the Langmuir isotherm model (R(2)=0.9763) with maximum adsorption capacity of 55.71 (mg/g). The kinetic studies showed that the adsorption follows the pseudo-second-order kinetics (R(2)=0.9999). From the results, it was concluded that Cs-g-PBA/SG nanocomposite is an excellent biosorbent for Cr removal from wastewater.


Assuntos
Acrilatos/química , Quitosana/química , Cromo/isolamento & purificação , Nanocompostos/química , Polímeros/química , Sílica Gel/química , Purificação da Água/métodos , Água/química , Adsorção , Cromo/química , Difusão , Glutaral/química , Concentração de Íons de Hidrogênio , Soluções , Fatores de Tempo , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
11.
Int J Biol Macromol ; 82: 440-52, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26434525

RESUMO

The present study was aimed to prepare the novel ternary biopolymeric beads of nanochitosan (NCS)/sodium alginate (SA)/microcrystalline cellulose (MC) for the removal of heavy metal copper from aqueous solution through batch adsorption mode. The polymeric beads were characterized before and after adsorption using FTIR, XRD and EDX-SEM studies. The efficiency of the adsorbent was analyzed by varying the parameters such as initial metal ion concentration, contact time, adsorbent dose and pH. The experimental data obtained were fitted in the isotherm models such as Langmuir, Freundlich and Tempkin models and in pseudo first and second order kinetics studies. The isotherm and kinetics models revealed that the adsorption was found to fit well with Freundlich isotherm and follows pseudo second-order kinetics.


Assuntos
Alginatos/química , Celulose/química , Quitosana/química , Cobre/química , Íons/química , Microesferas , Nanoestruturas/química , Adsorção , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Concentração de Íons de Hidrogênio , Cinética , Nanoestruturas/ultraestrutura , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
12.
Indian J Pharm Sci ; 77(1): 91-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25767323

RESUMO

Four major compounds were separated and identified from the methanol extracts of Nerium indicum flowers (Arali) using HPLC and mass spectral data. Through mass data, the chemical structures were elucidated as: trans5-O-caffeoylquinic acid (1), quercetin-3-O- rutinoside (2), luteolin-5-O-rutinoside (3) and luteolin-7-O-rutinoside (4). In addition, the cis isomers of 5-O-caffeoylquinic acid in Nerium indicum flowers were confirmed by Mass, HPLC and UV. The structures of these compounds confirmed with the help of liquid chromatography mass spectrometry.

13.
Int J Pharm ; 468(1-2): 214-22, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24742716

RESUMO

Nonobvious controlled polymeric pharmaceutical excipient, chitosan nanoparticles (CS-NPs) for lenalidomide encapsulation were geared up by the simple ionic cross linking method to get better bioavailability and to reduce under as well as overloading of hydrophobic and sparingly soluble drug lenalidomide towards cancer cells. Lenalidomide loaded chitosan nanoparticles (LND-CS-NPs) were in the size range of 220-295 nm and characterized by DLS, TEM, FT-IR, TGA and XRD. Encapsulation of lenalidomide over chitosan nanoparticles was observed about 99.35% using UV spectrophotometry method. In vitro release and the cytotoxic studies were performed using LND-CS-NPs. This study implies the new drug delivery route for lenalidomide and illustrates that the CS-NPs serves as the effective pharmaceutical carrier for sustained delivery of lenalidomide.


Assuntos
Inibidores da Angiogênese/química , Quitosana/química , Portadores de Fármacos , Excipientes/química , Talidomida/análogos & derivados , Sobrevivência Celular/efeitos dos fármacos , Química Farmacêutica , Reagentes de Ligações Cruzadas/química , Cristalografia por Raios X , Preparações de Ação Retardada , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lenalidomida , Luz , Células MCF-7 , Microscopia Eletrônica de Transmissão , Nanopartículas , Neoplasias/patologia , Tamanho da Partícula , Difração de Pó , Espalhamento de Radiação , Solubilidade , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Tecnologia Farmacêutica/métodos , Talidomida/química , Termogravimetria
14.
Int J Biol Macromol ; 67: 180-8, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24680901

RESUMO

The graft copolymerization of acrylonitrile onto cross linked chitosan was carried out using ceric ammonium nitrate as an initiator. The prepared cross linked chitosan-g-acrylonitrile copolymer was characterized using FT-IR and XRD studies. The adsorption behavior of chromium(VI), copper(II) and nickel(II) ions from aqueous solution onto cross linked chitosan graft acrylonitrile copolymer was investigated through batch method. The efficiency of the adsorbent was identified from the varying the contact time, adsorbent dose and pH. The results evident that the adsorption of metal ions increases with the increase of shaking time and metal ion concentration. An optimum pH was found to be 5.0 for both Cr(VI) and Cu(II), whereas the optimum pH is 5.5 for the adsorption of Ni(II) onto cross linked chitosan-g-acrylonitrile copolymer. The Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Adsorption isothermal data could be well interpreted by the Freundlich model. The kinetic experimental data properly correlated with the second-order kinetic model. From the above results it was concluded that the cross linked chitosan graft acrylonitrile copolymer was found to be the efficient adsorbent for removing the heavy metals under optimum conditions.


Assuntos
Resinas Acrílicas/química , Acrilonitrila/química , Adsorção , Quitosana/química , Cromo/química , Cobre/química , Íons/química , Cinética , Metais Pesados/química , Níquel/química , Espectroscopia de Infravermelho com Transformada de Fourier
15.
Int J Biol Macromol ; 66: 295-301, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24560947

RESUMO

Graft copolymerization of acrylonitrile on to cellulosic material derived from sisal fiber can be initiated effectively with ceric ammonium nitrate. The grafting conditions were optimized by changing the concentration of initiator and monomer. The change in crystallinity of the grafted polymeric samples was concluded from the XRD patterns. The prepared cellulose grafted acrylonitrile copolymer was used as an adsorbent to remove Cr (VI) ions from aqueous solutions. The efficiency of the adsorbent was identified from the variation in the percentage of adsorption with contact time, adsorbent dose and pH. From the observed results it was evident that the adsorption of metal ions increases with the increase in contact time and metal ion concentration. An optimum pH was found to be 5.0 for the removal of Cr (VI) from the aqueous solution. The results of the Langmuir, Freundlich, and pseudo first- and second-order studies revealed that the adsorption was found to fit well with Freundlich isotherm and follows pseudo second-order kinetics. From the above results, it was concluded that the cellulose-g-acrylonitrile copolymer was found to be an efficient adsorbent for the removal of Cr (VI) from aqueous waste generated from industries.


Assuntos
Acrilonitrila/química , Celulose/química , Cromo/química , Água/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Polímeros/química , Poluentes Químicos da Água/química , Purificação da Água/métodos
16.
Int J Biol Macromol ; 62: 59-65, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23994787

RESUMO

The extraction of cellulose from sisal fiber was done initially using the steam explosion method. The batch adsorption studies were conducted using the cellulose extracted from the sisal fiber and cellulose-g-acrylic acid as an adsorbent for the removal of Cu(II) and Ni(II) metal ions from aqueous solution. The effect of sorbent amount, agitation period and pH of solution that influence sorption capacity were investigated. From the observed results, it was evident that the adsorption of metal ions increases with the increase in contact time and adsorbent dosage. The optimum pH was found to be 5.0 for the removal of copper(II) and nickel(II) for both the extracted cellulose and cellulose-g-acrylic acid copolymer. The adsorption data were modeled using Langmuir and Freundlich isotherms. The experimental results of the Langmuir, Freundlich isotherms revealed that the adsorption of Cu(II) and nickel(II) ion onto cellulose extracted from the sisal fiber and cellulose-g-acrylic acid copolymer was found to fit well with Freundlich isotherm. The kinetics studies show that the adsorption follows the pseudo-second-order kinetics. From the above results, it was concluded that the cellulose-g-acrylic acid copolymer was found to be an efficient adsorbent.


Assuntos
Resinas Acrílicas/química , Agave/química , Celulose/química , Cobre/química , Cobre/isolamento & purificação , Níquel/química , Níquel/isolamento & purificação , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Termodinâmica , Fatores de Tempo
17.
Int J Biol Macromol ; 59: 165-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23603073

RESUMO

The removal of Pb (II) ions from aqueous solution by crosslinked (glutaraldehyde-chitosan/Nylon6/Polyurethane foam) and non crosslinked (chitosan/Nylon6/Polyurethane foam) blends has been investigated. Chitosan solution was blended with Nylon6 and Polyurethane foam in the ratio of 2:1:1 with and without crosslinking agent (glutaraldehyde), in order to obtain sorbents that are insoluble in aqueous acidic and basic solution. Batch adsorption studies were performed as a function of pH, contact time and adsorbent dose. The optimum pH required for maximum adsorption of lead was found to be 5. The equilibrium adsorption data has been tested for the Langmuir, Freundlich and Temkin isotherms. The data were suitable to Freundlich isotherm model for both the blends. The kinetic parameters of the adsorption process were estimated using the pseudo-first and pseudo-second order models. These data indicated that the adsorption process followed the pseudo-first-order kinetics.


Assuntos
Caprolactama/análogos & derivados , Quitosana/análogos & derivados , Quitosana/química , Glutaral/química , Chumbo/isolamento & purificação , Polímeros/química , Poliuretanos/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Caprolactama/química , Cátions Bivalentes , Concentração de Íons de Hidrogênio , Cinética , Termodinâmica
18.
Int J Biol Macromol ; 57: 204-12, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23500442

RESUMO

Chitosan nanorod with minimum particle size of <100 nm was prepared by crosslinking low molecular weight chitosan with polyanion sodium tripolyphosphate and physicochemically characterized (FT-IR, XRD, SEM, AFM, TGA and DSC) for waste water treatment. Its sorption capacity and sorption isotherms for chromium (Cr) were studied. The effect of initial concentration of Cr ions, sorbent amount, agitation period and pH of solution that influence sorption capacity were also investigated. It was found that nanochitosan in the solid state was rod shaped which could sorb Cr (VI) to Cr (III) ions effectively. Based on the Langmuir, the Freundlich and the Temkin sorption isotherms, the sorption capacity of chitosan nanoparticles is very high and the adsorbent favors multilayer adsorption. The kinetics studies show that the adsorption follows the pseudo-second-order kinetics, which infers the transformation of Cr (VI) to Cr (III). From the results it was concluded that nanochitosan is an excellent material as a biosorbent for Cr removal from water.


Assuntos
Quitosana/química , Cromo/química , Nanotubos/química , Águas Residuárias/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Nanotubos/ultraestrutura , Polifosfatos/química
19.
Artigo em Inglês | MEDLINE | ID: mdl-23291196

RESUMO

Chitosan/nylon6/polyurethane foam (CS/Ny6/PUF) ternary blend was prepared and chemically cross-linked with glutaraldehyde. Structural, thermal and morphological studies were performed for the prepared ternary blends. Characterizations of the ternary blends were investigated by Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM). The FTIR results showed that the strong intermolecular hydrogen bonds took place between CS, Ny6 and PUF. TGA and DSC studies reveal that the thermal stability of the blend is enhanced by glutaraldehyde as crosslinking agent. Results of XRD indicated that the relative crystalline of pure CS film was reduced when the polymeric network was reticulated by glutaraldehyde. Finally, the results of scanning electron microscopy (SEM) indicated that the morphology of the blend is rough and heterogeneous, further it confirms the interaction between the functional groups of the blend components.


Assuntos
Caprolactama/análogos & derivados , Quitosana/química , Reagentes de Ligações Cruzadas/química , Glutaral/química , Polímeros/química , Poliuretanos/química , Varredura Diferencial de Calorimetria , Caprolactama/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios X
20.
Int J Biol Macromol ; 53: 67-71, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23148945

RESUMO

Contamination of water by toxic heavy metals due to urbanization is a world-wide environmental problem, which changes chemical and biological properties of both surface and ground water. The heavy metals render the water unsuitable for drinking and are also highly toxic to human beings. Removal of heavy metals is therefore essential. Thus, in my present work batch adsorption studies have been used to remove the Cr(VI) from aqueous solution using chitin composite. The data obtained from batch method at optimized conditions have been subjected to Freundlich and Langmuir isotherm studies. The data were suitable for both models indicating favorability.


Assuntos
Bentonita/química , Quelantes/química , Quitina/química , Cromo/química , Adsorção , Algoritmos , Concentração de Íons de Hidrogênio , Modelos Químicos , Soluções , Poluentes Químicos da Água/química , Purificação da Água
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