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1.
Chemosphere ; : 142537, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38844101

RESUMO

The discharge of heavy metals into the environment has adversely affected the aquatic ecology due to their toxic and non-biodegradation nature. In this research, a three-dimensional graphene oxide/carboxymethylcellulose/aluminium sulphate (GOCAS) aerogel was synthesised and evaluated as a novel means for lead and zinc removal. The GOCAS aerogel was synthesised via ice-templating of graphene oxide with carboxymethylcellulose and aluminium sulphate as the crosslinking and functionalisation additives. Characterisation of the aerogel by various analytical techniques confirmed the successful integration of the substrates. The hydroxyl and sulphate groups in the aerogel were found to participate in the adsorption of both metals. The equilibrium of lead adsorption was found to correlate well to the Freundlich isotherm, while zinc adsorption better fitted to the Langmuir isotherm. The adsorption kinetic of both metals was found to be best described by the pseudo-second-order model. The interactive influences of concentration, temperature, contact time and dose on the metal elimination were explored by a central composite design, and the optimum adsorption capacity for lead was found to be 138.7 mg/g at a GOCAS dose of 20 mg, initial concentration of 100 mg/L, temperature of 50 °C and contact time of 45 min. The optimum adsorption capacity for zinc was 52.69 mg/g at 30 mg, 65 mg/L, 45 °C and 40 min. Furthermore, regeneration studies with hydrochloric acid eluant were successfully conducted for up to four adsorption-desorption cycles. Overall, this work demonstrates that GOCAS aerogel is a viable nanosorbent for the adsorption of lead and zinc from water systems.

2.
Polymers (Basel) ; 15(18)2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37765612

RESUMO

Wearable energy storage devices require high mechanical stability and high-capacitance flexible electrodes. In this study, we design a flexible supercapacitor electrode consisting of 1-dimensional carbon nanotubes (CNT), cellulose nanofibrils (CNF), and manganese dioxide nanowires (MnO2 NWs). The flexible and conductive CNT/CNF-MnO2 NWs suspension was first prepared via ultrasonic dispersion approach, followed by vacuum filtration and hot press to form the composite paper electrode. The morphological studies show entanglement between CNT and CNF, which supports the mechanical properties of the composite. The CNT/CNF-MnO2 NWs electrode exhibits lower resistance when subjected to various bending angles (-120-+120°) compared to the CNT/CNF electrode. In addition, the solid-state supercapacitor also shows a high energy density of 38 µWh cm-2 and capacitance retention of 83.2% after 5000 cycles.

3.
Nanomaterials (Basel) ; 11(10)2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34684908

RESUMO

Recent advancements in nanotechnology have improved our understanding of cancer treatment and allowed the opportunity to develop novel delivery systems for cancer therapy. The biological complexities of cancer and tumour micro-environments have been shown to be highly challenging when treated with a single therapeutic approach. Current co-delivery systems which involve delivering small molecule drugs and short-interfering RNA (siRNA) have demonstrated the potential of effective suppression of tumour growth. It is worth noting that a considerable number of studies have demonstrated the synergistic effect of co-delivery systems combining siRNA and small molecule drugs, with promising results when compared to single-drug approaches. This review focuses on the recent advances in co-delivery of siRNA and small molecule drugs. The co-delivery systems are categorized based on the material classes of drug carriers. We discuss the critical properties of materials that enable co-delivery of two distinct anti-tumour agents with different properties. Key examples of co-delivery of drug/siRNA from the recent literature are highlighted and discussed. We summarize the current and emerging issues in this rapidly changing field of research in biomaterials for cancer treatments.

4.
Polymers (Basel) ; 13(16)2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34451170

RESUMO

Poly(N-isopropylacrylamide) (polyNIPAm) microspheres were synthesized via the suspension polymerization technique. Thermal and redox initiators were compared for the polymerization, in order to study the effect of initiator type on the surface charge and particle size of polyNIPAm microspheres. The successful polymerization of NIPAm was confirmed by FTIR analysis. Microspheres of diameter >50 µm were synthesized when a pair of ammonium persulfate (APS) and N,N,N',N'-tetramethylene-diamine (TEMED) redox initiators was used, whilst relatively small microspheres of ~1 µm diameter were produced using an Azobis-isobutyronitrile (AIBN) thermal initiator. Hence, suspension polymerization using a redox initiator pair was found to be more appropriate for the synthesis of polyNIPAm microspheres of a size suitable for human embryonic kidney (HEK) cell culturing. However, the zeta potential of polyNIPAm microspheres prepared using an APS/TEMED redox initiator was significantly more negative than AIBN thermal initiator prepared microspheres and acted to inhibit cell attachment. Conversely, strong cell attachment was observed in the case of polyNIPAm microspheres of diameter ~90 µm, prepared using an APS/TEMED redox initiator in the presence of a cetyl trimethyl ammonium bromide (CTAB) cationic surfactant; demonstrating that surface charge modified polyNIPAm microspheres have great potential for use in cell culturing.

5.
Nanomaterials (Basel) ; 10(6)2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-32545513

RESUMO

: Hydrogen (H2) is a clean energy carrier which can help to solve environmental issues with the depletion of fossil fuels. Sodium borohydride (NaBH4) is a promising candidate material for solid state hydrogen storage due to its huge hydrogen storage capacity and nontoxicity. However, the hydrolysis of NaBH4 usually requires expensive noble metal catalysts for a high H2 generation rate (HGR). Here, we synthesized high-aspect ratio copper nanowires (CuNWs) using a hydrothermal method and used them as the catalyst for the hydrolysis of NaBH4 to produce H2. The catalytic H2 generation demonstrated that 0.1 ng of CuNWs could achieve the highest volume of H2 gas in 240 min. The as-prepared CuNWs exhibited remarkable catalytic performance: the HGR of this study (2.7 × 1010 mL min-1 g-1) is ~3.27 × 107 times higher than a previous study on a Cu-based catalyst. Furthermore, a low activation energy (Ea) of 42.48 kJ mol-1 was calculated. Next, the retreated CuNWs showed an outstanding and stable performance for five consecutive cycles. Moreover, consistent catalytic activity was observed when the same CuNWs strip was used for four consecutive weeks. Based on the results obtained, we have shown that CuNWs can be a plausible candidate for the replacement of a costly catalyst for H2 generation.

6.
J Mater Sci Mater Med ; 30(6): 62, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31127374

RESUMO

This study aimed to explore a potential use of fish scale-derived gelatin nanofibrous scaffolds (GNS) in tissue engineering due to their biological and economical merits. Extraction of gelatin was achieved via decalcification, sonication and lyophilization of mixed fish scales. To fabricate nano-scale architecture of scaffolds analogous to natural extracellular matrix, gelatin was rendered into nanofibrous matrices through 6-h electrospinning, resulting in the average diameter of 48 ± 12 nm. In order to improve the water-resistant ability while retaining their biocompatibility, GNS were physically crosslinked with ultraviolet (UV) irradiation for 5 min (UGN5), 10 min (UGN10) and 20 min (UGN20). On average, the diameter of nanofibers increased by 3 folds after crosslinking, however, Fourier transform infrared spectroscopy analysis confirmed that no major alterations occurred in the functional groups of gelatin. A degradation assay showed that UGN5 and UGN10 scaffolds remained in minimum essential medium for 14 days, while UGN20 scaffolds degraded completely after 10 days. All UGN scaffolds promoted adhesion and proliferation of human keratinocytes, HaCaT, without causing an apparent cytotoxicity. UGN5 scaffolds were shown to stimulate a better growth of HaCaT cells compared to other scaffolds upon 1 day of incubation, whereas UGN20 had a long-term effect on cells exhibiting 25% higher cell proliferation than positive control after 7 days. In the wound scratch assay, UGN5 scaffolds induced a rapid cell migration closing up to 79% of an artificial wound within 24 h. The current findings provide a new insight of UGN scaffolds to serve as wound dressings in the future. In the wound scratch assay, UGN5 induced a rapid cell migration closing up to 79% of an artificial wound within 24 h.


Assuntos
Escamas de Animais/química , Gelatina/química , Nanofibras/química , Engenharia Tecidual/métodos , Animais , Materiais Biocompatíveis , Adesão Celular , Linhagem Celular Tumoral , Proliferação de Células , Reagentes de Ligações Cruzadas/química , Eletroquímica , Matriz Extracelular , Fibroblastos/citologia , Peixes , Humanos , Queratinócitos/citologia , Teste de Materiais , Especificidade da Espécie , Espectroscopia de Infravermelho com Transformada de Fourier , Alicerces Teciduais , Raios Ultravioleta , Água/química , Cicatrização
7.
Mater Sci Eng C Mater Biol Appl ; 100: 388-395, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30948075

RESUMO

Cobalt oxide nanocubes incorporated with reduced graphene oxide (rGO-Co3O4) was prepared by using simple one-step hydrothermal route. Crystallinity and structural characteristics of the nanocomposite were analyzed and confirmed using X-ray diffraction (XRD) and Raman analysis, respectively. The cubical shape of the Co3O4 nanostructures and the distribution of Co3O4 nanocubes on the surface of rGO sheets were identified through field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) mapping analysis, respectively. Raman spectra depicted the presence of D and G bands for GO and rGO with different ID/IG values and thus confirmed the reduction of GO into rGO. The electrochemical study reflects that the rGO-Co3O4 nanocomposite shows good electrocatalytic activity in oxidation of depression biomarker serotonin (5-HT) in phosphate buffer (pH 7.2). The detection of 5-HT was carried out by using rGO-Co3O4 nanocomposite modified glassy carbon electrode under dynamic condition using amperometry technique with a linear range of 1-10 µM. The limit of detection and limit of quantification were calculated and found to be 1.128 and 3.760 µM, respectively with a sensitivity value of 0.133 µΑ·µM-1. The sensor showed selectivity in the presence of different interferent species such as ascorbic acid, dopamine and uric acid.


Assuntos
Carbono/química , Cobalto/química , Técnicas Eletroquímicas/métodos , Vidro/química , Grafite/química , Nanocompostos/química , Óxidos/química , Serotonina/análise , Catálise , Eletrodos , Nanocompostos/ultraestrutura , Oxirredução , Análise Espectral Raman , Difração de Raios X
8.
RSC Adv ; 9(29): 16472-16478, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-35516365

RESUMO

In this study, single wall carbon nanotubes (CNTs)/reduced graphene oxides (rGO) aerogels were prepared by a one-pot hydrothermal process without using a binder. The produced CNTs/rGO aerogel was used as cathode in electro-Fenton system for the decolouration of methylene blue (MB) and palm oil mill effluent (POME). The addition of CNTs increased the surface area, pore volume and conductivity of the rGO aerogel, which further enhanced their performance as cathode towards the decolouration of MB and POME via electro-Fenton reaction. Complete decolouration of MB using rGO aerogel without CNTs could not be achieved. The effect of electro-Fenton reaction parameters conducted using the aerogel samples including, current, electrolyte concentrations and pH, were investigated accordingly. The CNTs/rGO aerogel electrode also showed high stability and reusability for up to six consecutive treatment cycles for MB. Besides, the CNTs/rGO aerogel also showed good performance in treating POME with 69.8%, 47.6% and 58.1% of reduction in true colour, total organic carbon (TOC) and chemical oxygen demand (COD), respectively, via 60 minutes electro-Fenton reaction. This study showed that CNTs/rGO aerogels with high porosity and stability can be prepared using simple procedure without adding binder. This fully carbon-based aerogel can serve as effective cathode for decolouration of organic dye and effluent.

9.
Bioresour Technol ; 274: 134-144, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30502604

RESUMO

Graphene oxide/chitosan aerogel (GOCA) was prepared by a facile ice-templating technique without using any cross-linking reagent for metanil yellow dye sequestration. The adsorption performance of GOCA was investigated by varying the adsorbent mass, shaking speed, initial pH, contact time, concentration and temperature. The combined effects of adsorption parameters and the optimum conditions for dye removal were determined by response surface methodology. GOCA exhibited large removal efficiencies (91.5-96.4%) over a wide pH range (3-8) and a high adsorption capacity of 430.99 mg/g at 8 mg adsorbent mass, 400 mg/L concentration, 35.19 min contact time and 175 rpm shaking speed. The adsorption equilibrium was best represented by the Langmuir model. GOCA could be easily separated after adsorption and regenerated for re-use in 5 adsorption-desorption cycles thereby maintaining 80% of its adsorption capability. The relatively high adsorption and regeneration capabilities of GOCA render it an attractive adsorbent for treatment of azo dye-polluted water.


Assuntos
Compostos Azo/química , Quitosana/química , Grafite/química , Adsorção , Corantes/química , Géis/química , Gelo
10.
J Mater Chem B ; 6(8): 1195-1206, 2018 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32254180

RESUMO

Highly sensitive and selective immunosensors that can detect disease biomarkers at ultra-low levels in early stages are urgently needed to reduce mortality risks. A facile and efficient approach using sonochemical-assisted solvent graphene exfoliation and a hydrothermal synthesis method has been used to prepare graphene/titanium dioxide (G/TiO2) nanocomposites. Nanocomposites containing different ratios of graphene and TiO2 precursors were prepared to determine the optimum composition of G/TiO2 that has the highest conductivity and electrocatalytic properties. Characterisation methods such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and high resolution TEM (HRTEM) were used to study the crystallinity, surface characteristics, elemental composition, and morphology of the synthesised nanocomposites. The synthesised materials were also confirmed via Raman spectroscopy. Using ferricyanide as the redox active probe, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses indicated that 1 : 8 ratio of G/TiO2 exhibited the best current response and the lowest charge transfer resistance (Rct) of 1525 Ω. The potential of G/TiO2 for electrochemical sensing application was investigated using hydrogen peroxide (H2O2), a by-product of most enzymatic processes, as the analyte of interest. The sensitivity of the sensor towards H2O2 was 0.557 µA mM-1, with a limit of detection (LOD) at 56.89 µM. An in vitro cell proliferation assay was carried out to investigate the biocompatibility of the nanocomposites. The half-maximal inhibitory concentration (IC50) values obtained were >500 µg ml-1 for human lung fibroblasts (MRC5) and 5-25 µg ml-1 for human skin cells (HaCat).

11.
Biosens Bioelectron ; 94: 365-373, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28319904

RESUMO

An efficient electrochemical impedance genosensing platform has been constructed based on graphene/zinc oxide nanocomposite produced via a facile and green approach. Highly pristine graphene was synthesised from graphite through liquid phase sonication and then mixed with zinc acetate hexahydrate for the synthesis of graphene/zinc oxide nanocomposite by solvothermal growth. The as-synthesised graphene/zinc oxide nanocomposite was characterised with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and X-ray diffractometry (XRD) to evaluate its morphology, crystallinity, composition and purity. An amino-modified single stranded DNA oligonucleotide probe synthesised based on complementary Coconut Cadang-Cadang Viroid (CCCVd) RNA sequence, was covalently bonded onto the surface of graphene/zinc oxide nanocomposite by the bio-linker 1-pyrenebutyric acid N-hydroxysuccinimide ester. The hybridisation events were monitored by electrochemical impedance spectroscopy (EIS). Under optimised sensing conditions, the single stranded CCCVd RNA oligonucleotide target could be quantified in a wide range of 1.0×10-11M to 1.0×10-6 with good linearity (R =0.9927), high sensitivity with low detection limit of 4.3×10-12M. Differential pulse voltammetry (DPV) was also performed for the estimation of nucleic acid density on the graphene/zinc oxide nanocomposite-modified sensing platform. The current work demonstrates an important advancement towards the development of a sensitive detection assay for various diseases involving RNA agents such as CCCVd in the future.


Assuntos
Técnicas Biossensoriais/métodos , DNA de Cadeia Simples/química , Vírus de Plantas/isolamento & purificação , RNA Viral/isolamento & purificação , Sequência de Bases/genética , DNA de Cadeia Simples/genética , Espectroscopia Dielétrica , Grafite/química , Nanocompostos/química , Sondas de Oligonucleotídeos/química , Sondas de Oligonucleotídeos/genética , Vírus de Plantas/genética , RNA Viral/genética , Óxido de Zinco/química
12.
Colloids Surf B Biointerfaces ; 148: 392-401, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27639489

RESUMO

Fouling of marine surfaces has been a perpetual problem ever since the days of the early sailors. The tenacious attachment of seaweed and invertebrates to man-made surfaces, notably on ship hulls, has incurred undesirable economic losses. Graphene receives great attention in the materials world for its unique combination of physical and chemical properties. Herein, we present a novel 2-step synthesis method of graphene-silver nanocomposites which bypasses the formation of graphene oxide (GO), and produces silver nanoparticles supported on graphene sheets through a mild hydrothermal reduction process. The graphene-Ag (GAg) nanocomposite combines the antimicrobial property of silver nanoparticles and the unique structure of graphene as a support material, with potent marine antifouling properties. The GAg nanocomposite was composed of micron-scaled graphene flakes with clusters of silver nanoparticles. The silver nanoparticles were estimated to be between 72 and 86nm (SEM observations) while the crystallite size of the silver nanoparticles (AgNPs) was estimated between 1 and 5nm. The nanocomposite also exhibited the SERS effect. GAg was able to inhibit Halomonas pacifica, a model biofilm-causing microbe, from forming biofilms with as little as 1.3wt.% loading of Ag. All GAg samples displayed significant biofilm inhibition property, with the sample recording the highest Ag loading (4.9wt.% Ag) associated with a biofilm inhibition of 99.6%. Moreover, GAg displayed antiproliferative effects on marine microalgae, Dunaliella tertiolecta and Isochrysis sp. and inhibited the growth of the organisms by more than 80% after 96h. The marine antifouling properties of GAg were a synergy of the biocidal AgNPs anchored on the stable yet flexible graphene sheets, providing maximum active contact surface areas to the target organisms.


Assuntos
Anti-Infecciosos/farmacologia , Incrustação Biológica/prevenção & controle , Grafite/química , Química Verde/métodos , Nanopartículas Metálicas/química , Prata/química , Anti-Infecciosos/química , Biofilmes/efeitos dos fármacos , Halomonas/efeitos dos fármacos , Halomonas/fisiologia , Nanopartículas Metálicas/ultraestrutura , Microalgas/efeitos dos fármacos , Microalgas/fisiologia , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Reprodutibilidade dos Testes , Água do Mar/microbiologia , Análise Espectral Raman , Difração de Raios X
13.
J Nanosci Nanotechnol ; 16(3): 2438-46, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27455653

RESUMO

The highly pathogenic avian influenza (HPAI) virus subtype H5N1 has been found to be the most virulent and deadliest virus strain, with capability of interspecies transmission to human infection. Most human HPAI H5N1 cases were diagnosed late in their illnesses for medical care, resulting in severe complications that led to death. In this study, a novel graphene-enhanced electrochemical DNA biosensor had been fabricated for the detection of polymerase chain reaction (PCR) amplicon derived from the haemagglutinin (H5) gene of the HPAI. The graphene-enhanced DNA biosensor showed excellent linear correlation between PCR amplicon concentration and amperometric signal with a correlation coefficient, r2 of 0.9987. The amperometric response of the proposed biosensor was compared with conventional gel electrophoresis while the feasibility of the proposed sandwich sensing platform was verified via dot blot assay. The results obtained indicate that the electrochemical DNA biosensing assay is significantly more sensitive (P < 0.05) and time efficient. This work serves as a proof of concept in hopes for further development of the graphene enhanced electrochemical DNA biosensor into a portable, on-site screening platform for point-of-care detection of various pathogens.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas/instrumentação , Genes Virais , Virus da Influenza A Subtipo H5N1/genética , Corantes Fluorescentes , Limite de Detecção , Reação em Cadeia da Polimerase , Espectrometria por Raios X
14.
Anal Chim Acta ; 903: 131-41, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26709306

RESUMO

Graphene/zinc oxide nanocomposite was synthesised via a facile, green and efficient approach consisted of novel liquid phase exfoliation and solvothermal growth for sensing application. Highly pristine graphene was synthesised through mild sonication treatment of graphite in a mixture of ethanol and water at an optimum ratio. The X-ray diffractometry (XRD) affirmed the hydrothermal growth of pure zinc oxide nanoparticles from zinc nitrate hexahydrate precursor. The as-prepared graphene/zinc oxide (G/ZnO) nanocomposite was characterised comprehensively to evaluate its morphology, crystallinity, composition and purity. All results clearly indicate that zinc oxide particles were homogenously distributed on graphene sheets, without any severe aggregation. The electrochemical performance of graphene/zinc oxide nanocomposite-modified screen-printed carbon electrode (SPCE) was evaluated using cyclic voltammetry (CV) and amperometry analysis. The resulting electrode exhibited excellent electrocatalytic activity towards the reduction of hydrogen peroxide (H2O2) in a linear range of 1-15 mM with a correlation coefficient of 0.9977. The sensitivity of the graphene/zinc oxide nanocomposite-modified hydrogen peroxide sensor was 3.2580 µAmM(-1) with a limit of detection of 7.4357 µM. An electrochemical DNA sensor platform was then fabricated for the detection of Avian Influenza H5 gene based on graphene/zinc oxide nanocomposite. The results obtained from amperometry study indicate that the graphene/zinc oxide nanocomposite-enhanced electrochemical DNA biosensor is significantly more sensitive (P < 0.05) and efficient than the conventional agarose gel electrophoresis.


Assuntos
Técnicas Biossensoriais , Grafite/química , Nanocompostos , Óxido de Zinco/química , Microscopia Eletrônica de Varredura
15.
Bioresour Technol ; 128: 571-7, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23211482

RESUMO

Oil palm empty fruit bunch (EFB) fibers were employed to remove dyes from aqueous solutions via adsorption approaches. The EFB fibers were modified using citric acid (CA) and polyethylenimine (PEI) to produce anionic and cationic adsorbents, respectively. The CA modified EFB fibers (CA-EFB) and PEI-modified EFB fibers (PEI-EFB) were used to study the efficiency in removing cationic methylene blue (MB) and anionic phenol red (PR) from aqueous solutions, respectively, at different pHs, temperatures and initial dye concentrations. The adsorption data for MB on the CA-EFB fitted the Langmuir isotherm, while the adsorption of PR on the PEI-EFB fitted the Freundlich isotherm, suggesting a monolayer and heterogeneous adsorption behavior of the adsorption processes, respectively. Both modified fibers can be regenerated up to seven adsorption/desorption cycles while still providing as least 70% of the initial adsorption capacity.


Assuntos
Corantes/isolamento & purificação , Frutas/química , Extratos Vegetais/química , Ultrafiltração/métodos , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Água/química , Adsorção , Ânions , Araceae , Cátions , Corantes/química , Soluções , Poluentes Químicos da Água/química
16.
Bioresour Technol ; 102(15): 7237-43, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21620692

RESUMO

Chemically modified kenaf core fibres were prepared via esterification in the presence of citric acid (CA). The adsorption kinetics and isotherm studies were carried out under different conditions to examine the adsorption efficiency of CA-treated kenaf core fibres towards methylene blue (MB). The adsorption capacity of the kenaf core fibres increased significantly after the citric acid treatment. The values of the correlation coefficients indicated that the Langmuir isotherm fitted the experimental data better than the Freundlich isotherm. The maximum adsorption capacity of the CA-treated kenaf core fibres was found to be 131.6mg/g at 60°C. Kinetic models, pseudo-first-order, pseudo-second-order and intraparticle diffusion, were employed to describe the adsorption mechanism. The kinetic data were found to fit pseudo-second-order model equation as compared to pseudo-first-order model. The adsorption of MB onto the CA-treated kenaf core fibres was spontaneous and endothermic.


Assuntos
Ácido Cítrico/química , Hibiscus/química , Azul de Metileno/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Biodegradação Ambiental , Concentração de Íons de Hidrogênio , Cinética , Modelos Químicos , Soluções , Temperatura
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