Incorporation Of Single-walled Carbon Nanotubes Research Articles

Electrostatic Dissipation in 3D-Printable Silicone.

In this report, we describe the incorporation of single-walled carbon nanotubes (CNTs) into 3D printable siloxane elastomers for electrostatic dissipation. The composite was characterized, focusing on how rheological and mechanical properties of the siloxane are affected at various CNT loading levels. Electrical properties were also characterized to develop materials with effective electrostatic dissipation. We demonstrate that low loadings (<1 wt %) of CNTs can be sufficiently dispersed into silicone resins that can be 3D printed, and the resulting material shows a significant improvement in electrostatic dissipation through the reduction in electrical resistivity with minimal effect on its mechanical properties.

Hybrid nanofluids flow over a Riga plate surrounded by a variable porous medium for heat transfer optimization

Enhancing the heat transfer rate in hybrid nanofluids is significantly aided by a porous medium. The nanofluid’s heat transfer to the surrounding medium is more efficient due to the presence of a porous medium. The porous space also provides additional surface contact points for heat exchange and an intricate network of interconnected pores. This article elaborates on the incorporation of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) into water to perform hybrid nanofluids. The flow is considered over a Riga plate surrounded by a variable porous space. Various applications, including thermal management systems, microelectronics cooling, and energy conversion devices, benefit greatly from the study of hybrid nanofluid flow on a Riga plate. The similarity equations of the flow problem are easily tackled with the homotopy analysis method (HAM) built on fundamental homotopy mapping. Furthermore, with the increments in paramount parameters, the skin friction coefficient and heat transfer rate are remarkably meliorated under a higher modified Hartmann number. All reverberations are illustrated in graphs and Tables. From the obtained results it is observed that flow control capabilities are enabled by the variations in permeability in the case of hybrid nanofluids. It is also observed that hybrid nanofluids are more capable to enhance the thermal capabilities of the traditional fluids as compared to the mano nanofluids.

DFT modeling of new composite based on PANI/PVK functionalized With single-walled carbon nanotubes for optoelectronic applications

We present a comparative experimental and theoretical study of the vibrational, optical, and electronic properties of polyaniline at both emeraladine leuco-emeraldine forms and PVK. Our objective is first to select the appropriate form of PANI to be linked with PVK to form a hybrid polymer matrix. Then, on the basis of quantum chemical calculations, we present a theoretical study of a hybrid composite PANI/PVK functionalized with lower radius (5, 5) chiral single-walled carbon nanotubes (SWCNTs). The relationship structure-properties of the resulting nano-composite are proved based on the conformational and optical study made from Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) using B3LYP method with 6-31-G(d) basis set. First, it has been demonstrated that the resulting interaction between PANI and PVK leads to more advantageous properties, such as good optical absorption compatibility with the solar emission spectrum. It has also been found that after the incorporation of SWCNTs into the matrix of PANI/PVK hybrid polymer, a good organization of SWCNTs via π-staking interaction is imposed by polyaniline sequences. However, PVK moieties are grafted on the sidewalls of SWCNTs. Finally, the electronic structure of the resulting hybrid nano-composite PANI/PVK/SWCNTs was carried out with the use of different electrodes on both sides.

Use of non-covalently modified SWCNTs for enhancing the properties of BMI composites with a low loading

The properties of polymer nanocomposites depend greatly on the dispersion of nanoparticles in the polymer matrix. To improve the dispersion of single-walled carbon nanotubes (SWCNTs) in bismaleimide (BMI) resin, this paper developed a feasible method for non-covalent modification of SWCNTs by using polyvinylpyrrolidone (PVP). Moreover, the effect of functionalized SWCNTs on the properties of BMI composites was systematically investigated. The results showed that it was very effective for PVP as a surface modifier for the dispersion of SWCNTs in BMI resin. As a consequence, the electrical conductivity and mechanical properties of the SWCNT/BMI composites were all improved by the incorporation of SWCNTs at a low content. The study also presented that the heat resistance and thermal stability of SWCNT/BMI composites were simultaneously enhanced.

Effect of Single-Walled Carbon Nanotubes on the Cross-Linking Process in Natural Rubber Vulcanization.

In this study, the effect of single-walled carbon nanotubes (SWCNTs) on the cross-linking of natural rubber (NR) using organic peroxides was investigated. NR-SWCNTs nanocomposites were prepared in an open two-roller mill followed by vulcanization with the compression molding process. Three different organic peroxides, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane (T29), dicumyl peroxide (DCP), and 2,5-bis(tert-butylperoxy)-2,5-dimethyl-3-hexyne (T145), were used as vulcanizing agents. SWCNTs promote a remarkable reduction in the vulcanization time and increase the degree of cross-linking of vulcanized rubber when compared with neat or natural rubber-carbon-black composites; the same tendency was obtained in the NR-SWCNTs vulcanized with sulfur. Additionally, the mechanical performance of the NR-SWCNTs composites was significantly improved up to 75, 83, 27, and 10% for tensile strength, moduli, tear strength, and hardness. Raman spectroscopy studies evidence the occurrence of reaction between nanotube walls and free radicals generated from using organic peroxides during the vulcanization process. These results demonstrate that the incorporation of SWCNTs in combination with the use of organic peroxides for the NR vulcanization represents a potential alternative for the improvement of the physicochemical properties of NR composites.

Microwave Attenuation Studies of Polypyrrole-SWCNT Nanocomposite Films for Improved EMI Shielding

In the process of finding stable, lightweight, broadband, cost-effective and improved electromagnetic interference (EMI) shielding material, electromagnetic wave attenuation properties of polypyrrole (PPy)—single-walled carbon nanotube (SWCNT) nanocomposite hybrid films were investigated in X-band region (8.2–12.4 GHz) and reported in the present work. The incorporation of SWCNT as a nanofiller in polymer matrix exhibits enhanced EMI shielding performance as compared to pure polymer films. The substantial values of dielectric loss with good impedance matching contribute to improvement in EMI shielding performance. It is found that with an increase of SWCNT loading in polymer matrix from 0 wt% to 5 wt%, nanocomposite films display a gradual increase in AC conductivity and total shielding effectiveness. The maximum total shielding effectiveness of 32.10 dB and minimum reflection loss of −45.54 dB with a wide bandwidth of 3.1 GHz, were obtained for 5 wt% CNT loading. The present results revealed that the prepared nanocomposite films are appropriate materials for lightweight, broadband EMI shields for radar and stealth applications.

Electrospinning production of polymer nanofibers containing Ag nanoparticles or carbon nanotubes

Recent years’ electrospinning technology for fabrication of nanofibers of polymers with incorporation of nanoparticles made noticeable progress in different fields, including biomedicine due to their biocompatibility, adhesiveness, antibacterial properties, and sterile nature. In this study, the electrospinning production of antibacterial polyvinyl alcohol (PVA) nanofibers containing silver nanoparticles (AgNPs) was considered. The synthesis of the AgNPs was performed from the polymer-encapsulated AgNO3 precursor material in water with Ag atom reduction by an ultrasonication treatment. The effect of the AgNO3 concentration and the sonication time on the size and quantity of the obtained AgNPs on the PVA scaffold was studied. Absorption spectra were exploited for the control of the appearance of AgNPs in the suspension. From the peak position of the plasmon band observed in the absorption spectrum of the composite the average diameter of the as-prepared AgNPs was estimated as 55–60 nm. As it follows from scanning electron microscopy images the diameter of PVA:AgNPs nanofibers is about 250 nm. Nanofibers formed by polyvinylpyrrolidone (PVP) with incorporation of single-walled carbon nanotubes (SWNTs) were fabricated from the PVP alcohol solution containing SWNTs. The diameter of the nanofibers was in the range of 1–3 μm. Using a dielectric substrate and the collector of a special shape, a mat of fibers with preferred fiber orientation was prepared. Our estimation shows that about 90% of the fibers are oriented.

Separate immobilization of glucose oxidase and trehalase, and optimization of enzyme-carbon nanotube layers for the anode of enzymatic fuel cells utilizing trehalose

Insect cyborgs can be used as search robots in disaster areas and as environmental monitoring robots. In this study, we aimed to develop an anode for compact enzymatic fuel cells (EFCs) utilizing trehalose to power electronic devices implanted in such insects. Conventional trehalose-EFCs are fabricated by co-immobilization of glucose oxidase (GOx) and trehalase (TREH) on the surface of the anode. Here, we showed that current generation can be enhanced by separate immobilization of GOx and TREH using agarose. The effects of GOx-redox mediator layers, TREH loading, and the incorporation of single-walled carbon nanotubes (SWCNTs) on the performance of GOx-TREH anodes were investigated. The optimal arrangement of GOx-redox mediator layers with or without SWCNTs was determined. The highest oxidation current density (494 μA/cm2) was obtained at an electrode composed of three GOx-redox mediator layers and three GOx-redox mediator-SWCNTs layers, and agarose containing TREH. The bilirubin oxidase (BOD)-redox mediator layers and SWCNTs also influenced the performance of cathode. The highest reduction current intensity was obtained for the cathode with six BOD-redox mediator-SWCNTs layers. EFCs with the optimized anode and cathode showed a power density of ca. 15 μW/cm2 at a cell voltage of 0.3 V under a discharge current density of 50 μA/cm2.

Flexural Strength of an Indirect Composite Modified with Single-Wall Carbon Nanotubes.

The low resistance to fracture has limited the use of indirect composite resins for dental restorations, particularly in regions that are exposed to strong occlusal forces. To overcome this issue, different types of reinforcement for composites have been proposed, one of which is carbon nanotubes (CNTs). The aim of this study was to evaluate the flexural resistance of one commercial indirect composite resin (Sinfony, 3M/ESPE) after incorporation of single-wall carbon nanotubes (SWCNTs; Sigma-Aldrich, Inc., St. Louis, Missouri, United States) with or without the silanization form. Specimens of composite resin were fabricated in a Teflon mold. The composite resin was prepared according to the manufacturer's instructions (n = 10 for each group), with SWCNTs in three concentrations. The SWCNTs and SWCNT/SiO2-ATES specimens were evaluated by transmission electron microscopy, and a flexural test was conducted according to the ISO 4049/2009. Flexural strength data in MPa were submitted to one-way ANOVA following Tukey (p < 0.05). The SWCNTs did not improve the flexural strength of indirect composite resin when compared with the control, independent of the concentration added (p > 0.05). However, when SWCNTs and SWCNTs/SiO2-ATES were compared, the SWCNTs/SiO2-ATES showed higher values than the three concentrations of SWCNTs (p < 0.05). The silanization process improves the SWCNTs strength proprieties, but the modification of chemical bonding between SWCNT and SWCNT/SiO2-ATES modified resins, in different concentrations, did not improve the composite resin flexural strength.

Incorporation of single-walled carbon nanotubes in ultrafiltration support structure for the removal of steroid hormone micropollutants

Ultrafiltration (UF) is an established water treatment solution that operates at relatively low pressures, but cannot remove pollutants with sub-nanometre sizes such as steroid hormones. To tackle this challenge while maintaining a fast flow of water through the membrane, UF can be coupled with a nanoparticle layer that removes micropollutants via adsorption. In this study, a mechanical method of incorporating single-walled carbon nanotubes (SWCNTs) in the UF structure is demonstrated. Such an SWCNT–UF composite with a SWCNT loading of 2 g/m2 offered the high UF-range permeability, and partial removal (50–75%) of hormones from a 100 ng/L feed solution at neutral pH. A full breakthrough was not achieved in the three-hour experiments. The diffusion of hormones to the highly accessible SWCNT surface area was a limiting factor. Nevertheless, adsorption kinetics were very fast, and adsorption was independent of residence time in the range of 0.08–7.1 s. Since dynamic adsorption is kinetic-dependent, water quality parameters such as pH could affect the adsorptive interactions. For example, adsorption was poor at pH 11–12. Although more work is needed to accomplish the drinking water guideline of 1 ng/L with such a composite, the adsorbent–membrane concept is promising, because the adsorption efficiency can be further enhanced by increasing the particle loading and/or choosing adsorbents with higher surface areas.

In Vitro Biological Characterization of Natural Hydroxyapatite/Single-Walled Carbon Nanotube Composite Coatings Synthesized by Electrophoretic Deposition on NiTi Shape Memory Alloy

In the current work, the composite coating of natural hydroxyapatite (nHA)/single-walled carbon nanotubes (SWCNTs) with various contents of SWCNTs (0, 0.5, 1, and 2 wt.%) was applied on NiTi using electrophoretic deposition (EPD). Before the deposition process, the nanotubes were functionalized following the chemical oxidation method and characterized by FTIR. The sintering of samples was conducted at 800 °C for 3 h in a tube furnace under an argon atmosphere. The surface and cross-sectional microstructure of coatings was studied using a scanning electron microscope. The x-ray diffraction was utilized to investigate the effect of the SWCNTs secondary phase on the phase composition of the nHA layer after sintering. The incorporation of SWCNTs into the nHA layer resulted in the decomposition of some HA into the β-tricalcium phosphate phase. The tensile test was applied and displayed the enhancement in adhesion strength of nHA coating from 17.2 to 25 MPa after composing with 2 wt.% SWCNTs. The wettability of surfaces was assessed by measuring DMEM cell culture contact angles. The appraisement of the Ni ions release from the substrate demonstrated that the lowest release of Ni ions into DMEM cell culture after 7 days of incubation is achieved from NiTi coated with nHA-1 wt.% SWCNTs. The in vitro biocompatibility of the samples was pursued by MG63 osteoblast cell culturing and MTT assay. The highest cell attachment and proliferation on nHA-1 wt.% SWCNTs coating were attributed to the least toxic Ni ions release from the substrate of that.

Potentiometric screen-printed sensor for determination of oxybutynin hydrochloride

The present work describes the fabrication of disposable screen-printed oxybutynin hydrochloride (OXB) potentiometric sensors. The electrode matrix composition was investigated on the basis of the effect of the nature and concentration of sensing ionophores, anionic sites, plasticizers and nanomaterials. Incorporation of single-walled carbon nanotubes (SWCNTs) as transducer and (2, 3, 6-tri-O-methyl)-β-cyclodextrin as molecular recognition elements in the electrode matrix improved both the sensitivity and selectivity of the sensor towards oxybutynin hydrochloride. The fabricated sensors showed Nernstian slope of 57.5 ± 1.0 mV decade−1 in the concentration range from 10–6 to 10–2 mol L−1 OXB with detection limit of 8 × 10–7 mol L−1. Moreover, the presence of SWCNTs in the electrode matrix enhanced the potential reading stability, response time (< 4 s) and increased life time of the sensors (5 months). The developed sensors were successfully applied for determination of OXB in pharmaceutical formulations and biological fluids with agreeable average recoveries compared with the official methods.

The Effect of Carbon Substrate Morphology on the Electrochemical Performance of Electroactive Composite Coatings Based on Poly(3,6-di(3-aminophenylene)amino-2,5-dichloro-1,4-benzoquinone)

Electroactive composite coatings (CCs) are prepared on the basis of 3,6-di(3-aminophenylene)amino-2,5-dichloro-1,4-benzoquinone (DAPADCB) and its polymerization product poly-DAPADCB. We use two types of carbon substrates: (1) with a smooth surface, which are represented by glassy carbon (GC) and Graflex commercial graphite foil (GF), and (2) with a rough surface, which is represented by activated graphite foil (AGF). For the substrates of the first type, coatings are fabricated by oxidative polymerization on the substrate surface, while, for the second type, CCs are prepared by spreading a suspension of poly-DAPADCB in formic acid, in which the DAPADCB monomer is polymerized in advance, on the substrate surface. We study effects related to incorporation of single-wall carbon nanotubes and graphene oxide. The fabricated coatings exhibit high specific electrochemical capacitance (up to 2800 F/g) and extended cycling ranges (up to 2 V).

Ultra-sensitive, highly selective and completely reversible ammonia sensor based on polythiophene/SWCNT nanocomposite

Herein, we report polythiophene (PTh) based single-walled carbon nanotubes (SWCNT) nanocomposite (PTh/SWCNT) as a gas-sensor with extraordinary sensitivity and reproducibility at the room temperature (27 °C). The structures and morphologies of as-synthesized PTh/SWCNT nanocomposites were confirmed by scanning electron microscopy (SEM), transmittance electron microscopy (TEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD) techniques. These materials were studied for comparative stability of DC electrical conductivity under temperature ageing conditions; thus, PTh/SWCNT-3 (nanocomposite having 15 wt% of SWCNT with respect to the monomer, i.e. thiophene) was observed to be the most stable material. The change in conductivity of PTh/SWCNT-3 was calculated on exposure to the ammonia-vapours. It was noticed that the incorporation of SWCNT in PTh showed excellent sensitivity as compared to PTh, resulting in a significantly lower detection limit of 05 ppm in addition to the complete reversibility as well as excellent selectivity. The faster response, as well as the complete reversibility, may be attributed to relative higher surface-area of PTh/SWCNT-3, accessibility of appropriate sensing corridors and active sites. Most importantly, PTh/SWCNT-3 showed excellent selectivity towards ammonia than different tested volatile hydrocarbons. Finally, the sensing-mechanism was explained on the basis of involvement of polarons of PTh during adsorption and desorption of analyte gas.

Effect of single-walled carbon nanotubes on the cure and mechanical properties of reclaimed rubber/natural rubber blends

Reclaimed rubber (RR) is a recovered rubber material and has lower quality and properties compared to virgin rubber. To enhance its properties and subsequently widen the scope of applications, it is often blended with virgin natural rubber (NR). However, properties of the resultant RR/NR blends are negatively affected as the proportion of RR in the RR/NR blends is increased. This study seeks to explore the use of single-walled carbon nanotubes (SWCNTs) in RR/NR blends, where the dominant component is RR. Based on the tensile properties of specific formulations, the amounts of SWCNTs were first optimised by mixing varying amounts of SWCNTs and NR using conventional laboratory equipment. The effect of optimised SWCNTs on the cure and mechanical properties of RR/NR blends was thereafter investigated. The obtained results showed that upon the incorporation of SWCNTs, the minimum torque of RR/NR blends decreased while the scorch time and cure rate increased. Both the ultimate tensile strength and modulus at 100 %, 300 % and 500 % elongation increased, while the elongation at break slightly decreased. Furthermore, it was found that SWCNTs considerably increased hardness of RR/NR blends but insignificantly decreased the rebound resilience.

Single-wall carbon nanotube promoted allylic homopolymerization for holographic patterning

This article interrogates the mechanism for the incorporation of single-wall carbon nanotubes in the photo-initiated thiol-ene polymerization process and its application in holographic patterning. We find that single-wall carbon nanotube is able to turn on the allylic homopolymerization, which is not involved in the conventional thiol-ene photopolymerization process because of the autoinhibition of allyl monomer. This also leads to an enhancement of conversion for both thiol and allyl monomers. For the first time, the ability of single-wall carbon nanotube that promotes an autoinhibition monomer to homopolymerize is revealed. By applying this new mechanism, a flexible single-wall carbon nanotube-polymer composite film for the use of holographic patterning is demonstrated. The effects of the incorporation of single-wall carbon nanotubes on refractive index modulation and mechanical properties of a volume grating recorded are examined. It is shown that a substantial increase in refractive index modulation and diffraction efficiency is realized by small loading of single-wall carbon nanotubes (0.0015 wt%). This validate the proposed mechanisms provide a simple way to control the photopolymerization and therefore to tailor polymers for optical application uses.

Improving Charge Collection from Colloidal Quantum Dot Photovoltaics by Single-Walled Carbon Nanotube Incorporation.

Improving charge collection is one of the key issues for high-performance PbS colloidal quantum dot photovoltaics (CQDPVs) due to the considerable charge loss resulting from the low mobility and large defect densities of the 1,2-ethanedithiol-treated PbS quantum dot hole-transporting layer (HTL). To overcome these limitations, single-walled carbon nanotubes (SWNTs) and C60-encapsulated SWNTs (C60@SWNTs) are incorporated into the HTL in CQDPVs. SWNT-incorporated CQDPV demonstrates a significantly improved short-circuit current density (JSC), and C60@SWNT-incorporated CQDPV exhibits an even higher JSC than that of pristine SWNT. Both result in improved power-conversion efficiencies. Hole-selective, photoinduced charge extraction with linearly increasing voltage measurements demonstrates that SWNT or C60@SWNT incorporation improves hole-transporting behavior, rendering suppressed charge recombination and enhanced mobility of the HTL. The enhanced p-type characteristics and the improved hole diffusion lengths of SWNT- or C60@SWNT-incorporated HTL bring improvement of the entire hole-transporting length and enable lossless hole collection, which results in the JSC enhancement of the CQDPVs.

Enhance cell performance of DSSC by dye mixture, carbon nanotube and post TiCl4 treatment along with degradation study

This study employs betalain extract from beetroot and curcumin extract from turmeric as sensitizer source for TiO2 based dye-sensitized solar cell (DSSC) that has completely different absorption spectrum. The dye mixture has shown a wider absorption spectrum and higher light absorption than single individual dye. As a result, DSSC co-sensitized by the combination of dyes has shown enhanced cell performance. According to experimental results, DSSC sensitized by betalain and curcumin dye yield cell efficiency of 0.220% and 0.473% respectively. DSSCs have been co-sensitized with the mixture of dyes at 3 different volume ratios (1:1, 1:2 and 2:1) to find the optimized combination. The optimized mixture of betalain and curcumin dye (at 1:2 volume ratio) yields the maximum efficiency of 0.649%. The cell efficiency can be further improved by the incorporation of single-walled carbon nanotubes (SWCNTs) and post TiCl4 treatment. DSSC fabricated with FTO/SWCNT-TiO2 and TiCl4 treated FTO/SWCNT-TiO2 sensitized with the optimized dye mixture has the cell efficiency of 0.903% and 1.108%, respectively. Finally, the cell performance degradation has been measured by maturing the dye for 360 h in the normal atmospheric condition.

Fabrication of carbon nanotube-threephase organic photodetectors with high responsivity and wide spectrum and the underlying mechanisms

In this work, we incorporated single-walled carbon nanotubes (SWCNTs) into organic three-phase heterojunction active layer detectors, and systematically experimentally investigated the influences of single walled carbon nanotubes (SWCNTs) on the photoabsorption and photoelectric properties of the organic three-phase heterojunction detectors. Under -1 V bias voltage, the average photoresponsivity of three primary colors detector is 475 mA/W, about 2–3 times higher than that of similar devices that without SWCNTs. The average external quantum efficiency (EQE) increases to 111%. The results show that the incorporation of single-walled carbon nanotubes in the three-phase bulk heterojunction active layer maintains the original spectral morphology, while increases a higher degree of aggregation and crystallinity of the organic conjugated polymer, and further enhances a larger capacity of light absorption, regardless of the number of active layer's mixed phases. Under -1 V bias voltage, the average photoresponsivity of three primary colors detector is 475 mA/W, about 2–3 times higher than that of similar devices. The average external quantum efficiency (EQE) can be increased to 111%. In terms of carrier transport, SWCNT can increase the exciton dissociation area, dissociation rate of the film, and provide a fast transport channel for the charge, therefore improve the charge collection of the electrode. In a concentration range of 0.75–1.75 wt% and in high-energy photon excitation, single-walled carbon nanotubes can produce a multiple exciton generation.

Effect of Titanium Dioxide and Carbon Nanotubes on Polyaniline Nanocomposites for Heavy Metals Removal

The objective of this research is to investigate the effect of incorporation of titanium dioxide (TiO2) nanoparticles, single‐walled carbon nanotube (SWNT) and multi‐walled carbon nanotube (MWNT) in polyaniline (PAni) nanocomposites for heavy metals removal application. Nanocomposites of PAni/HA, PAni/HA/TiO2, PAni/HA/TiO2/SWNT and PAni/HA/TiO2/MWNT were synthesised using template free method and their chemical structures were examined by Fourier transform infra‐red (FTIR) Spectrophotometry and X‐ray Diffractometry (XRD). The surface morphology, thermal behavior and electrical conductivity were studied via scanning electron microscopy (SEM), thermogravimetry (TGA) analyses and resistivity meter, respectively. The incorporation of TiO2 nanoparticles in PAni nanocomposites improved the thermal stability but reduced the electrical conductivity of pristine PAni from 2.1 × 10−1 S/cm to 1.5 × 10−1 S/cm. The incorporation of SWNT in PAni nanocomposites improved the thermal stability and enhanced the electrical conductivity of PAni nanocomposites from 2.1 × 10−1 S/cm (pristine PAni) to 7.5 × 10−1 S/cm. The flame atomic absorption spectroscopy (FAAS) was used in the determination of the efficacy in heavy metals removal. It was found that the efficiency in heavy metals removal by PAni/HA/TiO2/SWNT had the ascending order of Pb2+ &lt; Cd2+ &lt; Cu2+ &lt; Fe3+. PAni/HA/TiO2/MWNT showed the highest heavy metals removal efficiency at 94% for Fe3+ ions within 4 h of contact time due to its improved thermal stability and moderate conductivity of 3.5 × 10−1 S/cm. The PAni/HA/TiO2/MWNT showed desirable performance in heavy metals removal (Fe3+ ions) with desirable recyclability up to 7 cycles and enhanced selectivity toward Fe3+ ions with a high removal efficiency of 85% in the presence of other interfering cation ions.