Polyaniline Shell Research Articles

Smart construction of polyaniline shell on Fe2O3 as enabling high performance anode toward flexible lithium-ion battery

Smart construction of polyaniline shell on Fe2O3 as enabling high performance anode toward flexible lithium-ion battery

Inhibiting irreversible Zn2+/H+ co-insertion chemistry in aqueous zinc-MoOx batteries for enhanced capacity stability

Rechargeable aqueous Zn-MoOx batteries are promising energy storage devices with high theoretical specific capacity and low cost. However, MoO3 cathodes suffer drastic capacity decay during the initial discharging/charging process in conventional electrolytes, resulting in a short cycle life and challenging the development of Zn-MoOx batteries. Here we comprehensively investigate the dissolution mechanism of MoO3 cathodes and innovatively introduce a polymer to inhibit the irreversible processes. Our findings reveal that this capacity decay originates from the irreversible Zn2+/H+ co-intercalation/extraction process in aqueous electrolytes. Even worse, during Zn2+ intercalation, the formed ZnxMoO3−x intermediate phase with lower valence states (Mo5+/Mo4+) experiences severe dissolution in aqueous environments. To address these challenges, we developed a first instance of coating a polyaniline (PANI) shell around the MoO3 nanorod effectively inhibiting these irreversible processes and protecting structural integrity during long-term cycling. Detailed structural analysis and theoretical calculations indicate that =N– groups in PANI@MoO3−x simultaneously weaken H+ adsorption and enhance Zn2+ adsorption, which endowed the PANI@MoO3−x cathode with reversible Zn2+/H+ intercalation/extraction. Consequently, the obtained PANI@MoO3−x cathode delivers an excellent discharge capacity of 316.86 mA h g−1 at 0.1 A g−1 and prolonged cycling stability of 75.49% capacity retention after 1000 cycles at 5 A g−1. This work addresses the critical issues associated with MoO3 cathodes and significantly advances the understanding of competitive multi-ion energy storage mechanisms in aqueous Zn-MoO3 batteries.

High-performance VO2/CNT@PANI with core–shell construction enable printable in-planar symmetric supercapacitors

As a progressive electronic energy storage device, the flexible supercapacitor holds tremendous promise for powering wearable/portable electronic products. Of various pseudocapacitor materials, vanadium dioxide (VO2) has garnered extensive attention due to its impressive theoretical capacitance. However, the challenges of inferior cycling life and lower energy density to be addressed. Herein, we prepare VO2 nanorods with winding carbon nanotubes (CNT) via a facile solvothermal route, followed by in situ polymerization of polyaniline (PANI) shell. Taking full advantage of the synergistic effect, the VO2/CNT@PANI composite delivers a high specific capacitance of 354.2F/g at 0.5 A/g and a long cycling life of ∼ 88.2 % over 5000 cycles resulting from the enhanced conductivity of CNT and stabilization of PANI shell. By screen printing the formulated inks with outstanding rheological behaviours, we manufacture an in-planar VO2/CNT@PANI symmetric supercapacitor (VO2/CNT@PANI SSC) device featuring an orderly arrangement structure. This device yields a remarkable areal energy density of 99.57 μWh/cm2 at a power density of 387.5 μW/cm2 while retaining approximately ∼ 87.6 % of its initial capacitance after prolonged use. Furthermore, we successfully powered a portable game machine for more than 2 min using two SSCs connected in series with ease. Therefore, this work presents a universal strategy that utilises combination and coating to boost electrochemical performance for flexible high-performance supercapacitors.

Development of Novel Multifunctional Electroactive, Self-Healing, and Tissue Adhesive Scaffold To Accelerate Cutaneous Wound Healing and Hemostatic Materials.

Designing a multifunctional conducting hydrogel wound dressing of suitable mechanical properties, adhesiveness, self-healing, autolytic debridement, antibacterial properties, and radical scavenging ability, as well as retaining an appropriate level of moisture around the wound is highly desirable in clinical application for treating cutaneous wounds healing. Here, we designed a novel class of electroactive hydrogel based on thiol-functionalized silver-graphene oxide nanoparticles (GO/Ag/TGA) core polyaniline (PANI) shell GO/Ag/TGA/PANI nanocomposites. Thus, a series of physically cross-linked hydrogel based on GO/Ag/TGA/PANI and poly(vinyl alcohol) (PVA) was prepared by freeze-thawing method. The hydrogel was characterized by XRD, UV, FTIR, TGA, TEM, SEM, Raman spectroscopy, cyclic voltammetry (CV), and four probes test. The hydrogel showed favorable properties such as excellent tensile strength, suitable gelation time (30-56 s), tunable rheological properties (G' ∼ 1 kPa), adhesiveness, and interconnected porous structure (freeze-dried). Besides this, the hydrogel also exhibits excellent exudate uptake capacity (10.4-0.2 g/g), high swelling ratio (72.4 to 93.5%), long-term antibacterial activity against multidrug-resistant (MDR) bacterial isolates, promising antioxidant (radical scavenging) efficiency, keeping the wound moisturized, prominent hemostatic efficiency, and fast self-healing ability to bear deformation. Interestingly, in vivo experiments indicated that electroactive hydrogels can significantly promote the healing rate of artificial wounds in rats, and histological analysis by H&E reveals higher granulation tissue thickness, collagen deposition, hair follicles, dermal papillary, keratinocytes, and marked increase (P < 0.05) in hydroxyproline at the wound site during 15 days of healing of impaired wounds. On the basis of vivo and vitro assay results, it is concluded that electroactive-hydrogel-attributed multifunctional properties may serve as suitable scaffold for treating chronic wound healing and skin regeneration.

Core-shell-shell nanocomposites structured polyaniline-rGO coated copolymer of NiFe2O4@poly(aniline-co-pyrrole) for sensitive Co2+ detection

A two-step in situ chemical polymerization approach that involved the simple in-situ oxidative polymerization of (ANI-co-Py) as a copolymer on NF nanoparticle NPs, followed by the succeeding in-situ oxidative polymerization of ANI-rGO on the P(ANI-co-Py)/NF core–shell structure, has successfully obtained a shell of polyaniline (PANI)- reduced graphene oxide (rGO) on poly(aniline-co-pyrrole)/NiFe2O4/P(ANI-co-Py)/NF core–shell. The resulting PANI-rGO/P(ANI-co-Py)/NF NCs consist of NiFe2O4 nanoparticles that acted as the “core” surrounding conducting copolymers, while the intermediate rGO serves as the bridge network connecting the copolymer and PANI, offering good structural stability as well as an effective electron transfer pathway. Moreover, the produced nanocomposite NCs also exhibit the core shell-shell structure with the features of electrode materials. A reliable sensor selective to Co2+ ion has been developed based on the high structural and compositional properties of the as-obtained PANI-rGO/P(ANI-co-Py)/NF NCs. Where a glassy carbon electrode (GCE) was coated by a slurry of synthesized PANI-rGO/P(ANI-co-Py)/NF NCs, which was stabilized using a suspension of Nafion (5 % suspension in ethanol) as a binding agent. A calibration curve of the current data and the corresponding concentrations of Co2+ ions have been established. From the calibration curve, the reliability of the linear dynamic range (0.1 nM–0.01 mM), the sensor sensitivity (204.2658 µA.µM−1.cm−2), and the lower limit of detection (99.27 ± 4.96 pM) have evaluated. Finally, the designed sensor was subjected to examining real environmental samples, where the fabricated sensor exhibited a successful high reproducibility. Recently, the development of sensors based on nanocomposites of organometallic on GCE has become key in the field of sensor development. The simple rapid synthesis of the PANI-rGO/P(ANI-co-Py)/NF NCs sensor will considerably contribute to the field of sensor management. In addition, the good performance of the PANI-rGO/P(ANI-co-Py)/NF NCs electrodes has drawn attention to them as promising electrode materials for high-performance sensors.

Multifunctional electrochromic hybrid PANI@WO3 core-shell for energy generation and storage

Materials that can be deposited easily and shows multifunctional application are always in demand. Two technologically important materials, polyaniline (PANI) and tungsten trioxide (WO3) have been amalgamated using an uncommon, yet simple, technique of deposition, chronoamperometry to obtain a hybrid core-shell structure and its application in three different areas of electrochromic display, electrocatalysis and energy storage has been investigated. Electrodepositing WO3 and PANI onto highly conducting substrates one on top of other, resulted in formation of PANI (shell), WO3 (Core) (PANI@WO3) electrode resulting in a highly uniform fibrous surface structure. Electrochemistry performed using the conventional three electrode step up suggested a very good charge storing capacity, stability also indicating a pseudo capacitive nature which was later confirmed with the help of Nyquist plot. Besides very good values of areal capacitance (855 mF/cm2), power density (6.5 kW/cm2) and energy density (1.09 kWh/cm2) established its supercapacitive performance. Next, its behaviour as an electrocatalyst was studied by duly plotting polarisation curves and their corresponding Tafel plots. The PANI@WO3 electrode deposited on a transparent electrode exhibited green-blue-yellow-transparent color switching under different bias conditions with a very small voltage of 0.5 V. A fast switching of 0.4 s and a great color contrast of ∼50 % in visible as well IR region were displayed making the electrochemically deposited core-shell a good candidate for multifunctional application in energy generation, storage with an inerrability with smart electrochromic windows.

Preparation and properties of erythritol/exfoliated graphite nanoplatelets @ polyaniline microencapsulated phase change materials with improved photothermal conversion efficiency

Multifunctional microencapsulated phase change materials (MePCMs) with sugar alcohols as core and functional polymers as shell are of great importance for the applications of sugar alcohols as phase change materials (PCMs). However, the preparation of such kinds of MePCMs was restricted due to the water solubility and the high phase change temperature of sugar alcohols. Herein, we proposed a facial method and prepared a series of novel multifunctional sugar alcohols @ polyaniline (PANI) MePCMs with m-erythritol (ME) as core, PANI as shell, and exfoliated graphite nanoplatelets (GNPs) as thermal conductive and photothermal conversion enhancement fillers. The prepared MePCMs were composed of GNPs@ME particles microencapsulated by PANI shell when the loading of GNPs was no more than 4 wt%. Otherwise, the GNPs@ME particles would be wrapped by excessive GNPs at first and then microencapsulated by the PANI shell. The prepared MePCMs exhibited good anti-leakage performance. The latent heat storage capacity of the prepared MePCMs could attain 254.3 J·g−1. The thermal conductivity of the MePCMs with 8 wt% GNPs could be greatly enhanced to 196 % higher than that of the MePCMs without GNPs. Meanwhile, due to the synergetic nucleating effect of PANI and GNPs, the supercooling of ME in the MePCM was effectively suppressed from about 100 °C to about 56 °C with 2 wt% GNPs. The prepared MePCMs also exhibited excellent photothermal conversion performance. Consequently, the results reported here could pave the way for the preparation of sugar alcohol-based multifunctional MePCMs for solar thermal applications and latent heat storage systems.

A soy protein-based adhesive with improved mechanical and electromagnetic shielding properties by employment of core@double-shell BT@PDA@PANI fillers

Resolving indoor electromagnetic interference (EMI) and radiation pollution caused by electromagnetic waves have become paramount. Plywood is broadly used in interior decoration and give them EMI shielding function will be significant for addressing these issues. Herein, inspired by the mussel underwater bonding strategy and oyster, polydopamine (PDA) graft transition layer was introduced between inorganic BaTiO3 (BT) core layer and organic polyaniline (PANI) shell layer to construct controllable core@double-shell BT@PDA@PANI nanoparticles. The epoxide polymer and aldehyde-decorated carbon dots (CDs) were used as crosslinkers to form the covalent bonds and dynamic covalent bonds within the adhesive network. The core@double-shell nanoparticles were used as a reinforcing element and crosslinker to construct an organic–inorganic hybrid protein adhesive. This as-prepared protein adhesive exhibits remarkable improvements in wet shear strength (1.16 MPa), dry shear strength (1.97 MPa), and water resistance. Encouragingly, the plywood with in-situ formulated adhesives is an absorption dominated EMI shielding material and reveals an excellent EMI SET of 38.04 dB EMI in the X-band, significantly outperforming most of the reported synthetic materials. This outstanding performance is attributable to its superior conductivity and unique hierarchical structure of plywood. Therefore, this study offers a facile, environmentally-friendly, and economically feasible strategy for preparing high-performance adhesives to address indoor EMI problems.

Electrochemical sensor based on ion-selective membrane of silica/polyaniline nano-composites for selective determination of uranyl ions

Life threatening impacts of uranium have necessitated its detection and determination in economically feasible way before it arrives in living bodies. Therefore, a new form of UO22+ ion-selective electrode has been fabricated based on membrane of silica/polyaniline core-shell nano-composites, in-spite of traditionally used ionophores, because of intrinsically conducting nature of polyaniline. For the synthesis of these nano-composites, silica has been extracted from rice straw in its cristobalite form, whereas the layer of polyaniline shell has been grafted on silica nanoparticles through in-situ chemical oxidative polymerization technique by cautiously maintaining the electro-active nature of these core-shell nano-composites. The chemical composition, purity, topography, morphology and surface polarity of this nano-composite assembly have been studied through various spectroscopic techniques such as, FT-IR, EDS, FESEM, UV–Vis, DLS and Raman spectroscopy. The results confirm that silica/polyaniline nano-composites have been synthesized with desired semi-cavities and electrostatic surface charge, which is responsible for binding with target cation, i.e., UO22+for its potentiometric determination in aqueous medium even in the presence of interfering metal ions. The designed potentiometric sensor has shown fast and stable linear response in concentration range of 1 × 10−6 to 1 × 10−2 M with the limit of detection of 1.4 × 10−7 M which is 100-folds lower than the detection limit calculated using spectrofluorometry. In addition to this, the proposed UO22+ion-selective electrode has been successfully employed as an indicator electrode for the determination of uranyl ions in complexometric titration and for the estimation of UO22+ions in real life based environmental sample, i.e., soil.

Enhanced polymerization interface of Ni12P5 nanowires toward high-rate and durable cathode for alkaline Ni–Zn batteries

Alkaline nickel-zinc batteries have attracted more attention due to their inherent safety and high specific energy. However, the cycling stability of Ni–Zn batteries is still an urgent problem. Herein, we fabricate the Ni12P5@PANI core-shell structure by polyaniline cladding on the Ni12P5 nanowires. The polyaniline not only effectively improves the specific capacity of Ni12P5, but also greatly enhances the cyclic stability. The optimized Ni12P5@PANI nanowires provide a specific capacity of 272.8 mAh g−1 at 1 A g−1 (189.2 mAh g−1 at 10 A g−1, 69.4% retention rate) and long-life cycling (93% capacity retention after 1000 cycles at 10 A g−1). Moreover, the theoretical calculations indicate that the polyaniline is easy to polymerize on the surface of Ni12P5, and the lower formation energy verifies that the polyaniline shell layer can effectively promote the structural stability of Ni12P5, thus enhancing the cycle life. In addition, the assembled Ni12P5@PANI//Zn battery retains 112.3% capacity retention after 500 cycles at 3 A g−1, and provides a high energy density of 287.9 Wh kg−1 and power density of 49.1 kW kg−1 (based on the mass of active substance). This work provides a feasible high-rate and durable cathode material for alkaline Ni–Zn batteries.

Synergistically optimizing interlaminar and electromagnetic interference shielding behavior of carbon fiber composite based on interfacial reinforcement

The development of structure-function integrated materials is an important trend in military field. How to achieve the enhanced interfacial property and electromagnetic interference (EMI) shielding property of carbon fiber (CF) reinforced polymer (CFRP) simultaneously is the main challenge at present. Herein, the mechanically strengthened CFRP with superior EMI shielding property was developed by the introduction of reduced graphene oxide/Fe3O4, i.e., RGF into epoxy resin, combined with CF modified by uniform polyaniline (PANI) shell. The interlaminar shear analysis indicated that the RGF nanofiller in resin matrix and uniform PANI shell on CF could effectively optimize the interlaminar shear behavior due to the enhanced cohesive strength and adhesion strength among interface phase. Notably, the resultant composite achieved an interlaminar shear strength of 80.4 MPa, 37.4% higher than that of virgin CF/epoxy composite. Additionally, thanks to the excellent electromagnetic wave loss of RGF as well as the unique alternating multilayer, the super EMI shielding effectiveness of 78.5 dB with was achieved when the RGF content was 4.0 wt%, much higher than 34.7 dB of virgin CF/epoxy composite. The excellent interlaminar shear and EMI shielding behaviors endow the composite with potential application in military field, which providing a new strategy for the development of high-performance CF/epoxy composite.

Preparation and Characterization of PANI Surface Modified HMX/F2602 Microcapsule Composites

AbstractUsing HMX with a particle size of 1–10 μm as the main explosive, a dense polyaniline (PANI) shell was prepared on the surface of HMX/F2602 by in situ polymerization, and an energetic composite material HMX−F@PANI (HMX−F2602@PANI) with a microcapsule structure was constructed. The structure and properties of the samples were characterized by SEM, XRD, XPS, DSC, mechanical sensitivity and electrostatic spark sensitivity tests. The results showed that the chemical structure and polycrystalline morphology of the crystals did not change during the coating process, and remained β‐HMX. The preparation of PANI shell greatly improves the coating degree of the explosive surface and reduces the exposure of crystal. In addition, compared with HMX/F2602, HMX−F@PANI is more excellent in improving thermal stability and reducing the electrostatic spark sensitivity, which is attributed to the advantages of microcapsule structure and good electrical conductivity of PANI.

Effects of in-situ acid dopants on the latent heat storage properties and morphology of palmitic acid @ polyaniline microencapsulated phase change materials

Fatty acids (FA) based microencapsulated phase change materials (MePCMs) with acid doped polyaniline (PANI) as shell are promising multi-functional MePCMs. In order to investigate the effects of different in-situ acid dopants on the latent heat storage properties and the morphology of the prepared FA@PANI MePCMs, herein, we selected palmitic acid (PA) as a representative FA, and five kinds of PA@PANI MePCMs were prepared via interface polymerization of aniline with HCl, H3PO4, salicylic acid, p-aminobenzenesulfonic acid and taurine (TA) as in-situ dopants, respectively. Characterization of the prepared MePCMs revealed that when TA was used as in-situ dopant, PA@PANI MePCMs with good spherical morphology and high encapsulation ratio (R) could be obtained. Specifically, when the TA/aniline molar ratio was no more than 0.4, the latent heat of the prepared spherical PA@PANI MePCMs could attain 120 J/g, corresponding to an R of 55%. There was no chemical interaction existed between the PA core and the PANI shell, while the crystallinity of PA was not affected by the microencapsulation. On the other hand, the other four acids are unfavorable for obtaining PA@PANI MePCMs with high R and good spherical morphology. This work proved that TA is a suitable in-situ acid dopant for preparing in-situ acid doped FA@PANI MePCMs. It also implied that it is better to dop the PANI shell with strong proton acids after the FA@PANI MePCMs have been prepared where strong proton acid doped FA@PANI MePCMs are preferred.

“Three‐in‐One” Strategy that Ensures V2O5·nH2O with Superior Zn2+ Storage by Simultaneous Protonated Polyaniline Intercalation and Encapsulation

The structural engineering of vanadium oxides is considered as a research hotspot for enhancing their electrochemical performances applied to aqueous zinc‐ion batteries (AZIBs). In regard to the laggard Zn2+ transfer kinetic and fragile structure of V2O5·nH2O, herein, a feasible “three‐in‐one” strategy is adopted to design the structural engineering of V2O5·nH2O nanobelts through simultaneous protonated polyaniline intercalation and encapsulation (denoted as P‐VOH@P) to boost their Zn2+ storage. First, the enlarged interlayer pillared by polyaniline accelerates Zn2+ transfer speed and weakens electrostatic attraction between negative [VO] units and positive Zn2+. Second, polyaniline shell directly stabilizes the P‐VOH@P heterostructure. Third, the composition of protonated polyaniline not only improves the conductivity, but also contributes partial capacity though the reversible intrachain electronic migration. As expected, the Zn//P‐VOH@P cell exhibits specific capacities of 387 mAh g−1 with low‐mass‐loading cathode (2 mg cm−2) and 345 mAh g−1 with high‐mass‐loading cathode (5 mg cm−2) in coin cells and 360 mAh g−1 in pouch cells at 0.1 A g−1. Furthermore, the Zn//P‐VOH@P cell shows low capacity decay and good rate property. Herein, light is shed on a new strategy of engineering the vanadium oxide structure for postgeneration cathode material and paves a novel way to the advanced energy‐storage system.

PANI coated NiMoOP nanoarrays as efficient electrocatalyst for oxygen evolution

To obtain high-efficiency and affordable electrocatalysts for water splitting application, constructing specific nanostructures is believed as an effective solution to pursue advanced structure characteristics for improved catalysis property. In this work, a shell-core structured catalyst of polyaniline coated hybrid Ni3Mo2P-MoO3 nanoarrays is designed for oxygen evolution. The polyaniline shell not only assures merit of high conductivity for accelerated charge transfer, but also benefits the catalysis stability. The coupling effect between nitrogen species of polyaniline shell and metals of core materials imparts improved intrinsic catalysis activity and more active sites. Hence, the present sample manifests excellent catalytic efficiency for alkali water oxidation, only needing low overpotentials of 290 and 412 mV at high current densities of 100 and 400 mA cm−2, respectively. The development of shell-core catalyst using polyaniline as shell material paves a way for activating other transition metal catalytic materials and supplies a basis for industrial water splitting applications.

Facile synthesis of palygorskite/polyaniline/ZnO nanocomposites as strong wideband microwave absorbers

Herein, the palygorskite/polyaniline/ZnO (Pal/PANI/ZnO) nanocomposites were synthesized by using facile two-step solution method with palygorskite as a carrier. It was confirmed that the introduction of palygorskite can effectively prevent the free agglomeration of polyaniline shells and ZnO rods. Interestingly, the acquired ternary nanocomposites show excellent microwave absorption properties in multi frequency bands. Specifically, the optimized sample exhibits a minimum reflection loss (RL) value of −57.75 dB at 5.52 GHz in the C band, with an additional RL peak of −47.44 dB at 15.60 GHz at a thickness of merely 1.88 mm in the Ku band. Meanwhile, the effective absorption bandwidth (RL < -10 dB) reaches 6.56 GHz in the range of 11.44–18.00 GHz at a thickness of 2.08 mm. Therefore, our results could contribute to the design of palygorskite based nanocomposites as the high-absorption and strong-bandwidth microwave absorbers.

Insights into the interaction between PANI and Au NPs of magnetic core‐shell Fe3O4/PANI/Au catalysts with remarkable catalytic performance in 4‐NP reduction

AbstractMagnetic Fe3O4/PANI core‐shell composites were prepared as the support of gold catalysts. The Fe3O4 magnetic core was prepared by solvothermal reaction and coated with polyaniline (PANI) shell via in situ aniline polymerization on Fe3O4 surface. Au nanoparticles were loaded on Fe3O4/PANI composites through gold sol adsorption and in situ reduction method to prepare Fe3O4/PANI/Au(Sol) and Fe3O4/PANI/Au(In Situ) catalysts, respectively. We found that the initial activities of Fe3O4/PANI/Au(Sol) were higher than that of Fe3O4/PANI/Au(In Situ) due to the small size effect of Au in catalysts. Although the size of Au in Fe3O4/PANI/Au(In Situ) was bigger than that in Fe3O4/PANI/Au(Sol), it should be noted that both of Fe3O4/PANI/Au(Sol) and Fe3O4/PANI/Au(In Situ) possessed good catalytic recycling stability. The conversion of 4‐NP was still above 97% and 99% after 15 cycles for Fe3O4/PANI/Au(Sol) and Fe3O4/PANI/Au(In Situ), respectively. The good catalytic stability for Fe3O4/PANI/Au(In Situ) could be attributed to the stronger interaction between PANI and Au NPs. We believe that our work provides an effective strategy for the preparation of long‐life catalysts and the investigations can be used to design other conductive polymers supported noble metal catalysts.

Preparation and characterization of polyaniline microcapsule loaded with 2,2′‐azobis(2‐methylpropionitrile) initiator and its controlled release

AbstractThe thermal curing of acrylate adhesive consisting of acrylate monomer or prepolymer and 2,2′‐azobis(2‐methylpropionitrile) (AIBN) initiator is quite common. However, the two‐component adhesive is not suitable for large areas, large gap bonding, or potting because of its fast‐curing speed and intense heat release. To solve these problems, microencapsulating the initiator AIBN in the adhesive and controlling its release is proposed. Here, a new series of polyaniline microcapsules loaded with AIBN for the preparation of delayed‐release initiator were synthesized via an emulsification‐polymerization method. The coumarone indene resins were doped in polyaniline to control the release of the encapsulated AIBN. The characterization results indicate that the coumarone indene resin had been successfully mixed into the microcapsule polyaniline shell, and the interior of the microcapsules doped with resin had a rich pore structure. When a Span 80 and Tween 80 composite emulsifying system was used and its concentration was controlled at 0.1%–1.0%, the resulting microcapsules were homogeneous with good dispersibility. The release of the microcapsule was slow, and the release rate and release time could be precisely controlled by adjusting the type and doping amount of coumarone indene resin in the microcapsule shell material as well as the external temperature. For example, when the doping amount of coumarone indene resins in the PANI shell material increased from 0.2 to 1.0 g or when the temperature ranges from 75to 85°C, the release time of AIBN from the microcapsule decreased from 9 to 2 h and 12 to 3 h, respectively. With increasing demands for high performance delayed‐release initiators, the prepared polyaniline microcapsules loaded with AIBN show great potential for practical applications in adhesive, self‐healing coating, and petroleum exploitation.

Zinc-doped silica/polyaniline core/shell nanoparticles towards corrosion protection epoxy nanocomposite coatings

Commercial paints and coatings can serve as a protective barrier for metallic substrates in a corrosive environment. A considerable variety of nanostructures can be embedded in a polymeric coating to achieve both barrier and active protection. This research aims to elucidate the role of polyaniline (PANI) as an active polyelectrolyte modifier for the surface modification of mesoporous silica nanoparticles (MSNs) doped with zinc cations (Zn2+). To characterize the samples, we employed different techniques, including field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), N2 adsorption-desorption, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), inductively coupled plasma optical emission spectroscopy (ICP-OES), rheometric mechanical spectroscopy (RMS), differential scanning calorimetry (DSC), tensile, and electrochemical impedance spectroscopy (EIS). Characterization of PANI-MSNs proved the formation of PANI shells onto the surface of silica cores, and pH triggered the release of Zn2+ at the alkaline condition. Enhancement in rheological, thermal, and mechanical characteristics revealed good dispersion and chemical interaction between PANI coated nanoparticles and the epoxy matrix. Moreover, epoxy nanocomposite coatings illustrated a dual barrier/active protection after 50 days of salt immersion.

Chemiresistor type formaldehyde sensor using polystyrene/polyaniline core-shell microparticles

Formaldehyde is one of the toxic volatile organic compounds and is known to be a carcinogen and a major cause of sick building syndrome. In this study, polystyrene (PS)/polyaniline (PANI) core-shell type microparticles with narrow size distributions were prepared by applying the Swelling-Diffusion-Interfacial Polymerization Method (SDIPM). The PANI shell was uniformly coated on the PS core and the PANI loading efficiency estimated by gravimetric reaction yield analysis was 98.69%. A formaldehyde sensor device was fabricated by a solution casting of the PS/PANI core-shell type microparticles on the Interdigitated Electrodes (IDEs). The PS/PANI coated IDE sensor showed an excellent sensitivity for formaldehyde in range of 1–50 ppm at room temperature as follows: −9.9% of response for 1 ppm and −37.6% of response for 50 ppm. In addition, it showed a clear reversibility indicating that the sensor could be reused at least 3 times for the detection of formaldehyde.