Highly Anisotropic Thermally Conductive Dielectric Polymer/Boron Nitride Nanotube Composites for Directional Heat Dissipation.

An ideal dielectric material for microelectronic devices requires a combination of high anisotropic thermal conductivity and low dielectric constant (ɛ') and loss (tan δ). Polymer composites of boron nitride nanotubes (BNNTs), which offer excellent thermal and dielectric properties, show promise for developing these dielectric polymer composites. Herein, a simple method for fabricating polymer/BNNT composites with high directional thermal conductivity and excellent dielectric properties is presented. The nanocomposites with directionally aligned BNNTs are fabricated through melt-compounding and in situ fibrillation, followed by sintering the fibrous nanocomposites. The fabricated nanocomposites show a significant enhancement in thermal properties, with an in-plane thermal conductivity (K‖) of 1.8 Wm-1K-1-a 450% increase-yielding a high anisotropy ratio (K‖/K⊥) of 36, a 1700% improvement over isotropic samples containing only 7.2 vol% BNNT. These samples exhibit a 120% faster in-plane heat dissipation compared to the through-plane within 2 s. Additionally, they display low ɛ' of ≈3.2 and extremely low tan δ of ≈0.014 at 1 kHz. These results indicate that this method provides a new avenue for designing and creating polymer composites with enhanced directional heat dissipation properties along with high K‖, suitable for thermal management applications in electronic packaging, thermal interface materials, and passive cooling systems.

Novel Polymer Composites for Lead-Free Shielding Applications.

Polymer nanocomposites have recently been introduced as lead-free shielding materials for use in medical and industrial applications. In this work, novel shielding materials were developed using low-density polyethylene (LDPE) mixed with four different filler materials. These four materials are cement, cement with iron oxide, cement with aluminum oxide, and cement with bismuth oxide. Different weight percentages were used including 5%, 15%, and 50% of the cement filler with LDPE. Furthermore, different weight percentages of different combinations of the filler materials were used including 2.5%, 7.5%, and 25% (i.e., cement and iron oxide, cement and aluminum oxide, cement and bismuth oxide) with LDPE. Bismuth oxide was a nanocomposite, and the remaining oxides were micro-composites. Characterization included structural properties, physical features, mechanical and thermal properties, and radiation shielding efficiency for the prepared composites. The results show that a clear improvement in the shielding efficiency was observed when the filler materials were added to the LDPE. The best result out of all these composites was obtained for the composites of bismuth oxide (25 wt.%) cement (25 wt.%) and LDPE (50 wt.%) which have the lowest measured mean free path (MFP) compared with pure LDPE. The comparison shows that the average MFP obtained from the experiments for all the eight energies used in this work was six times lower than the one for pure LDPE, reaching up to twelve times lower for 60 keV energy. The best result among all developed composites was observed for the ones with bismuth oxide at the highest weight percent 25%, which can block up to 78% of an X-ray.

Polymeric nanocomposite electrode for enhanced electrochemical detection of α-lipoic acid: Application in neuroinflammation prevention and clinical analysis.

Using poly (vanillin-co-chitosan)/functionalized MWCNTs/GCE (PV-CS/f-MWCNTs/GCE) as a polymeric nanocomposite modified electrode, the present investigation has been conducted on the electrochemical detection of α-lipoic acid (α-LA) to prevent the activation of microglia inflammation of the nervous system. The manufacture of modified polymeric nanocomposite electrodes was carried out using the established electropolymerization process. Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analyses of structure revealed that the electropolymerization of poly (vanillin-co-chitosan) on the surface of the f-MWCNTs modified electrode was successful. Vanillin-co-chitosan electropolymerization on f-MWCNTs as electroactive sheets can enhance the signal for α-LA electrochemical sensors, according to research on the electrochemical characteristics utilizing cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methodologies. The PV-CS/f-MWCNTs/GCE demonstrated that it had a sensitivity of 0.04664 µA/µM, a detection limit of 0.012 µM, and an excellent response, linear range, and wide linear range to α-LA from 0 to 3000 µM. The results of the application of PV-CS/f-MWCNTs/GCE for determining the concentration of α-LA in a prepared real sample of human serum by DPV and human lipoic acid ELISA Kit analyses via standard addition method illustrated the substantial conformity between the findings of both assays. The results of the DPV analyses resulted in acceptable recovery values (97.60%-99.10%) and appropriate values of the Relative Standard Deviation (RSD) (3.58%-5.07%), which demonstrated the great applicability and accuracy of the results of PV-CS/f-MWCNTs/GCE for determining α-LA concentration in biological fluids and pharmaceutical specimens.

Study of Prepared Lead-Free Polymer Nanocomposites for X- and Gamma-ray Shielding in Healthcare Applications.

Polymer composites were synthesized via melt mixing for radiation shielding in the healthcare sector. A polymethyl-methacrylate (PMMA) matrix was filled with Bi2O3 nanoparticles at 10%, 20%, 30%, and 40% weight percentages. The characterization of nanocomposites included their morphological, structural, and thermal properties, achieved using SEM, XRD, and TGA, respectively. The shielding properties for all synthesized samples including pristine PMMA were measured with gamma spectrometry using a NaI (Tl) scintillator detector spanning a wide range of energies and using different radioisotopes, namely Am-241 (59.6 keV), Co-57 (122.2 keV), Ra-226 (242.0), Ba-133 (80.99 and 356.02 keV), Cs-137 (661.6 keV), and Co-60 (1173.2 and 1332.5 keV). A substantial increase in the mass attenuation coefficients was obtained at low and medium energies as the filler weight percentage increased, with minor variations at higher gamma energies (1173 and 1332 keV). The mass attenuation coefficient decreased with increasing energy except under 122 keV gamma rays due to the K-absorption edge of bismuth (90.5 keV). At 40% loading of Bi2O3, the mass attenuation coefficient for the cesium 137Cs gamma line at 662 keV reached the corresponding value for the toxic heavy element lead. The synthesized PMMA-Bi2O3 nanocomposites proved to be highly effective, lead-free, safe, and lightweight shielding materials for X- and gamma rays within a wide energy range (<59 keV to 1332 keV), making them of interest for healthcare applications.

Synthesis and Characterization of the Mixed Metal Oxide of ZnO-TiO2 Decorated by Polyaniline as a Protective Film for Acidic Steel Corrosion: Experimental, and Computational Inspections.

In this work, the preparation, characterization, and evaluation of a novel nanocomposite using polyaniline (PANi) functionalized bi-metal oxide ZnO-TiO2 (ZnTiO@PANi) as shielding film for carbon steel (CS)-alloy in acidic chloride solution at 298 K was studied. Different spectroscopic characterization techniques, such as UV-visible spectroscopy, dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR) approaches, as well as other physicochemical methods, such as X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), and field emission scanning electron microscope (FESEM), were used to describe the produced nanocomposites. The significance of these films lies in the ZnO-TiO2 nanoparticle's functionalization by polyaniline, a material with high conductivity and electrochemical stability in acidic solutions. The mechanistic findings of the corrosion inhibition method were obtained by the use of electrochemical methods including open-circuit potentials (OCP) vs. time, potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). The results indicate that the synthesized ZnTiO@PANi is a powerful acidic corrosion inhibitor, and its inhibition effectiveness is 98.86% in the presence of 100 ppm. Additionally, the charge transfer resistance (Rp) value augmented from 51.8 to 432.7, and 963.7 Ω cm2 when the dose of PANi, and ZnTiO@PANi reached 100 ppm, respectively. The improvement in Rp and inhibition capacity values with an increase in nanocomposite dose is produced by the nanocomposite additives covering a larger portion of the surface, resulting in a decrease in alloy corrosion. By identifying the probable regions for molecule adsorption on the steel substrate, theoretical and computational studies provided significant details regarding the corrosion mitigation mechanism. The possibility of substituting old poisonous small substances with inexpensive and non-hazardous polymeric materials as shielding layers for utilization in the oilfield sectors is an important suggestion made by this research.

Prospects of Polymeric Nanocomposite Membranes for Water Purification and Scalability and their Health and Environmental Impacts: A Review.

Water shortage is a major worldwide issue. Filtration using genuine polymeric membranes demonstrates excellent pollutant separation capabilities; however, polymeric membranes have restricted uses. Nanocomposite membranes, which are produced by integrating nanofillers into polymeric membrane matrices, may increase filtration. Carbon-based nanoparticles and metal/metal oxide nanoparticles have received the greatest attention. We evaluate the antifouling and permeability performance of nanocomposite membranes and their physical and chemical characteristics and compare nanocomposite membranes to bare membranes. Because of the antibacterial characteristics of nanoparticles and the decreased roughness of the membrane, nanocomposite membranes often have greater antifouling properties. They also have better permeability because of the increased porosity and narrower pore size distribution caused by nanofillers. The concentration of nanofillers affects membrane performance, and the appropriate concentration is determined by both the nanoparticles' characteristics and the membrane's composition. Higher nanofiller concentrations than the recommended value result in deficient performance owing to nanoparticle aggregation. Despite substantial studies into nanocomposite membrane manufacturing, most past efforts have been restricted to the laboratory scale, and the long-term membrane durability after nanofiller leakage has not been thoroughly examined.

Humic acid-coated hydrated ferric oxides-polymer nanocomposites for heavy metal removal in water.

Water pollution by toxic heavy metals poses a threat to the environment and human bodies. Herein, a novel hydrated ferric oxide nanoparticle (HFO) based hybrid adsorbent was fabricated for the removal of toxic Cu(II), Cd(II) and Pb(II) from water. HFOs were immobilized into a porous resin D-201, and then this nanocomposite HFO-D201 was coated with humic acid (HA) to enhance the binding sites of target metals. Both HFOs and HA contribute to the sequestration of heavy metals. The as-synthesized hybrid adsorbent HA-HFO-D201 exhibited excellent performance on the removal of Cu(II), Cd(II), and Pb(II) in a pH range of 3-9, while no Fe leaching was observed. The presence of natural organic matter (20 mg C/L) has limited influences on the adsorption, and more than 85% of the target metals can be removed after treatment. HA-HFO-D201 showed preferable adsorption toward Cu(II) and Pb(II) (1 mg/L) from the background Ca2+ solution at much higher concentrations (100 mg/L), while the retention of Cd(II) (1 mg/L) decreased to some extent. Fixed-bed column experiments exhibited that the treatment capacities of HA-HFO-D201 are 90 bed volumes (BV) for Cd(II), 410 BV for Pb(II) and > 800 BV for Cu(II) of simulated contaminated water to meet the WHO drinking water standard. Meanwhile, depleted HA-HFO-D201 can be readily regenerated by a chelating agent Na2EDTA for repeated use. The hybrid adsorbent HA-HFO-D201 has excellent potential to remove heavy metals in water treatment systems.

Electroactive polymeric nanocomposite BC-g-(Fe3O4/GO) materials for bone tissue engineering: in vitro evaluations.

Tissue engineering is a cutting-edge approach for using advanced biomaterials to treat defective bone to get desired clinical results. In bone tissue engineering, the scaffolds must have the desired physicochemical and biomechanical natural properties in order to regenerate complicated defective bone. For the first time, polymeric nanocomposite material was developed using cellulose and co-dispersed nanosystem (Fe3O4/GO) by free radical polymerization to fabricate porous polymeric scaffolds via freeze drying. Various characterizations techniques, such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM)/energy dispersive X-ray (EDX), and universal testing machine (UTM) were used to investigate structural, morphological, and mechanical properties. Swelling, biodegradation, and wetting analysis were also performed to evaluate their physicochemical behavior. Intercalation of Fe3O4 nanoparticles into GO-sheets promoted their dispersion into the polymeric matrix. All porous scaffolds possessed a well-interconnected porous structure, while the synergistic effect of Fe3O4/GO reinforces the mechanical strength of porous scaffolds. The compressive strength and Young's modulus were increased by increasing Fe3O4 amount, and maximum mechanical strength was found in HFG-4 and least in HFG-1. However, these porous scaffolds have different swelling and biodegradation behavior due to the variable Fe3O4 intercalations into GO-sheets. Antibacterial activities of porous scaffolds were studied against severe Gram-positive and Gram-negative pathogens and increased Fe3O4 amount in nanosystem increased the antibacterial activities. The cell viability and morphology of pre-osteoblast (MC3T3-E1) cell lines were studied against porous scaffolds and increased cell viability and proliferation were observed from HFG-1 to HFG-4. Hence, the electroactive material could be the potential material for bone tissue engineering.

Synthesis, Characterization and Electrochemical Performance of a Redox-Responsive Polybenzopyrrole@Nickel Oxide Nanocomposite for Robust and Efficient Faraday Energy Storage.

A polybenzopyrrole@nickel oxide (Pbp@NiO) nanocomposite was synthesized by an oxidative chemical one-pot method and tested as an active material for hybrid electrodes in an electrochemical supercapattery device. The as-prepared composite material exhibits a desirable 3D cross-linked nanostructured morphology and a synergistic effect between the polymer and metal oxide, which improved both physical properties and electrochemical performance. The unprocessed material was characterized by X-ray diffraction, FTIR and UV-Vis spectroscopy, scanning electron microscopy/energy disperse X-ray analysis, and thermogravimetry. The nanocomposite material was deposited without a binder on gold current collectors and investigated for electrochemical behavior and performance in a symmetrical two- and three-electrode cell setup. A high specific capacity of up to 105 C g-1 was obtained for the Pbp@NiO-based electrodes with a gravimetric energy density of 17.5 Wh kg-1, a power density of 1925 W kg-1, and excellent stability over 10,000 cycles.

Preferable phosphate sequestration using polymer-supported Mg/Al layered double hydroxide nanosheets.

The efficient removal of phosphate from waters is critical to mitigating eutrophication. Recently, layered double hydroxides (LDHs) have been believed to be promising adsorbents for phosphate removal. Nevertheless, the scaled-up application of LDHs is limited by the difficulties of separation, excessive pressure drops, and potential metal leaching. In this study, a millimeter-sized nanocomposite, MgAl-201, was fabricated by impregnating Mg/Al LDH nanosheets into a polystyrene anion exchanger D201. The resulting MgAl-201 combines the inherent affinity of Mg/Al LDH toward phosphate and the excellent hydrodynamic performance of the support material. Benefiting from the shielding effect from the cross-linked polymeric host, MgAl-201 exhibits satisfactory chemical stability in the range of pH 3-11 with a negligible metal release. Adsorption experiments show that MgAl-201 has superb applicability to neutral phosphate-contaminated waters. It reaches adsorption equilibrium within 270 min, and the maximum adsorption capacity calculated by the double Langmuir model is 52.0 mg/g. Meanwhile, MgAl-201 exhibits more preferable adsorption toward phosphate than D201 when coexisting anions are at relatively high levels. FTIR and XPS surveys revealed that two distinct adsorption interactions were involved in phosphate removal, that is, electrostatic interactions from the quaternary ammonium groups bonded on the host and the interlayer exchangeable anions in the encapsulated Mg/Al LDH, and specific inner-sphere complexation from the -OH groups in the Mg/Al LDH layers. For wastewater application, a satisfactory treatable volume of 580 BV was achieved to reduce the effluents from 2.0 mg/L to 0.5 mg/L, which was up to 8 times that of the traditional anion exchanger D201. Furthermore, MgAl-201 could be easily regenerated using the Na2CO3-NaCl binary solution and maintained good reusability without significant capacity loss after 5 adsorption-desorption cycles. The results suggest that MgAl-201 is of great application capability for preferable phosphate sequestration in advanced wastewater treatment.

Piezo-Resistive Flexible Pressure Sensor by Blade-Coating Graphene-Silver Nanosheet-Polymer Nanocomposite.

The demand for flexible pressure sensors in wearable devices is dramatically increasing. However, challenges still exist in making flexible pressure sensors, including complex or costly fabrication processes and difficulty in mass production. In this paper, a new method is proposed for preparing the flexible pressure sensors that combines an imprinting technique with blade-coating of a graphene-silver nanosheet-polymer nanocomposite. The piezo-resistive type flexible pressure sensor consists of interdigital electrodes and nanocomposite as a sensing layer, as well as a micropillar array structure. The morphology of the sensitive layer of the sensor is characterized by scanning electron microscopy (SEM). The response performance, sensitivity, and stability of the sensor are investigated. The test results show that the initial resistance of the pressure sensor is only 1.6 Ω, the sensitivity is 0.04 kPa-1, and the response time is about 286 ms. In addition, a highly hydrophobic wetting property can be observed on the functional structure surface of the sensor. The contact angle is 137.2 degrees, revealing the self-cleaning property of the sensor. Finally, the prepared sensor is demonstrated as a wearable device, indicating promising potential in practical applications.

A review on the features, performance and potential applications of hydrogel-based wearable strain/pressure sensors.

Over the past few years, development of wearable devices has gained increasing momentum. Notably, the demand for stretchable strain sensors has significantly increased due to many potential and emerging applications such as human motion monitoring, prosthetics, robotic systems, and touch panels. Recently, hydrogels have been developed to overcome the drawbacks of the elastomer-based wearable strain sensors, caused by insufficient biocompatibility, brittle mechanical properties, complicated fabrication process, as the hydrogels can provide a combination of various exciting properties such as intrinsic electrical conductivity, suitable mechanical properties, and biocompatibility. There are numerous research works reported in the literature which consider various aspects as preparation approaches, design strategies, properties control, and applications of hydrogel-based strain sensors. This article aims to present a review on this exciting topic with a new insight on the hydrogel-based wearable strain sensors in terms of their features, strain sensory performance, and prospective applications. In this respect, we first briefly review recent advances related to designing the materials and the methods for promoting hydrogels' intrinsic features. Then, strain (both tensile and pressure) sensing performance of prepared hydrogels is critically studied, and alternative approaches for their high-performance sensing are proposed. Subsequently, this review provides several promising applications of hydrogel-based strain sensors, including bioapplications and human-machine interface devices. Finally, challenges and future outlooks of conductive and stretchable hydrogels employed in the wearable strain sensors are discussed.

LDPE/Bismuth Oxide Nanocomposite: Preparation, Characterization and Application in X-ray Shielding.

Recently developed polymer-based composites could prove useful in many applications such as in radiation shielding. In this work, the potential of a bismuth oxide (Bi2O3) nanofiller based on an LDPE polymer was developed as lead-free X-ray radiation shielding offering the benefits of lightness, low-cost and non-toxic compared to pure lead. Three different LDPE-based composites were prepared with varying weight percentages of Bi2O3: 5%, 10% and 15%. The characterizations were extended to include structural properties, physical features, mechanical and thermal properties, and radiation shielding efficiency for the prepared nanocomposites. The results revealed that the incorporation of the Bi2O3 nanofiller into an LDPE improved the density of the composites. There was also a slight increase in the tensile strength and tensile modulus. In addition, there was a clear improvement in the efficiency of the shield when fillers were added to the LDPE polymer. The LDPE + Bi2O3 (15%) composite needed the lowest thickness to attenuate 50% of the incident X-rays. The LDPE + Bi2O3 (15%) polymer can also block around 80% of X-rays at 47.9 keV. In real practice, a thicker shield of the proposed composite materials, or a higher percentage of the filler could be employed to safely ensure the radiation is blocked.

A New Hybrid Sensitive PANI/SWCNT/Ferrocene-Based Layer for a Wearable CO Sensor.

Developing a sensing layer with high electroactive properties is an important aspect for proper functionality of a wearable sensor. The polymeric nanocomposite material obtained by a simple electropolymerization on gold interdigitated electrodes (IDEs) can be optimized to have suitable conductive properties to be used with direct current (DC) measurements. A new layer based on polyaniline:poly(4-styrenesulfonate) (PANI:PSS)/single-walled carbon nanotubes (SWCNT)/ferrocene (Fc) was electrosynthesized and deposed on interdigital transducers (IDT) and was characterized in detail using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoemission spectroscopy (XPS), and X-ray diffraction (XRD). The sensor characteristics of the material towards carbon monoxide (CO) in the concentration range of 10-300 ppm were examined, showing a minimal relative humidity interference of only 1% and an increase of sensitivity with the increase of CO concentration. Humidity interference could be controlled by the number of CV cycles when a compact layer was formed and the addition of Fc played an important role in the decrease of humidity. The results for CO detection can be substantially improved by optimizing the number of deposition cycles and enhancing the Fc concentration. The material was developed for selective detection of CO in real environmental conditions and shows good potential for use in a wearable sensor.

Nanofibrillated chitosan coated highly ordered titania nanotubes array/graphene nanocomposite with improved biological characters.

Designing multifunctional surfaces is key to develop advanced materials for orthopedic applications. In this study, we design a double-layer coating, assembled onto the completely regular titania nanotubes (cRTNT) array. Benefiting from the biological and topological characteristics of chitosan nanofibers (CH) and reduced graphene oxide (RGO) through a unique assembly, the designed material features promoted osteoblast cell viability, prolonged antibiotic release profile, as well as inhibited bacterial biofilm formation. The synergistic effect of RGO and CH on the biological performance of the surface is investigatSed. The unique morphology of the nanofibers leads to the partial coverage of RGO-modified nanotubes, providing an opportunity to access the sublayer properties. Another merit of this coating lies in its morphological similarity to the extracellular matrix (ECM) to boost cellular performance. According to the results of this study, this platform holds promising advantages over the bare and bulk biopolymer-modified TNTs.

Biodegradable Antimicrobial Food Packaging: Trends and Perspectives.

This review presents a perspective on the research trends and solutions from recent years in the domain of antimicrobial packaging materials. The antibacterial, antifungal, and antioxidant activities can be induced by the main polymer used for packaging or by addition of various components from natural agents (bacteriocins, essential oils, natural extracts, etc.) to synthetic agents, both organic and inorganic (Ag, ZnO, TiO2 nanoparticles, synthetic antibiotics etc.). The general trend for the packaging evolution is from the inert and polluting plastic waste to the antimicrobial active, biodegradable or edible, biopolymer film packaging. Like in many domains this transition is an evolution rather than a revolution, and changes are coming in small steps. Changing the public perception and industry focus on the antimicrobial packaging solutions will enhance the shelf life and provide healthier food, thus diminishing the waste of agricultural resources, but will also reduce the plastic pollution generated by humankind as most new polymers used for packaging are from renewable sources and are biodegradable. Polysaccharides (like chitosan, cellulose and derivatives, starch etc.), lipids and proteins (from vegetal or animal origin), and some other specific biopolymers (like polylactic acid or polyvinyl alcohol) have been used as single component or in blends to obtain antimicrobial packaging materials. Where the package's antimicrobial and antioxidant activities need a larger spectrum or a boost, certain active substances are embedded, encapsulated, coated, grafted into or onto the polymeric film. This review tries to cover the latest updates on the antimicrobial packaging, edible or not, using as support traditional and new polymers, with emphasis on natural compounds.

A Mini-Review on Anion Exchange and Chelating Polymers for Applications in Hydrometallurgy, Environmental Protection, and Biomedicine.

The rapidly increasing demand for technologies aiming to resolve challenges of separations and environmental protection causes a sharp increase in the demand for ion exchange (IX) and chelating polymers. These unique materials can offer target-selective adsorption properties vital for the removal or recovery of harmful and precious materials, where trace concentrations thereof make other techniques insufficient. Hence, recent achievements in syntheses of IX and chelating resins designed and developed in our research group are discussed within this mini-review. The aim of the present work is to reveal that, due to the diversified and unique physiochemical characteristics of the proposed materials, they are not limited to traditional separation techniques and could be used in multifunctional areas of applications, including catalysis, heat management, and biomedicine.

Release promoter-based systematically designed nanocomposite(s): a novel approach for site-specific delivery of tumor-associated antigen(s) (TAAs).

The aim of present approach was to design and develop mannose functionalized reverse polymeric nanocomposite(s) system based on release promoter (MRPRPNs). Thus, the composition of the present formulation was optimized by employing the systematic design of experiments (DoE) for screening and optimization using L8-Array Taguchi and 3-level-3-factor Box-Behnken Design (BBD). Further, the developed formulation was observed for its preferential internalization by professional antigen presenting cells (macrophages/dendritic cells) and prompt release of loaded antigen in a pH-dependent manner. The optimized formulation was also extensively characterized for average hydrodynamic diameter, surface potential, poly dispersity index of reverse polymeric nanocomposite(s) which were recoded to be 189.4 ± 8.52 nm, 0.111 ± 0.024, -23.4 ± 2.0 mV, respectively; while percentage entrapment efficiency of OVA in MRPRPNs to be 60.17 ± 2.41%. The release pattern of OVA from MRPRPNs was consistent at pH 7.4. However, at acidic pH (≈5.5) where in protons (H+) are in-filtered into the core of MRPRPNs thereby generating the pressure, resultantly causing and creating the pores or disruption of the system thus allowed a prompt release (≈60-70%) of encapsulated OVA from interior to outer milieu within 1 h. MRPRPNs were preferentially internalized through receptor-mediated endocytosis and released the loaded OVA into the cytosol of RAW 264.7 cells. From the above findings, it can be concluded that reverse polymeric system could significantly be loaded with immunobioactive(s) and could potentially deliver the contents at the specific site for the better therapeutic outcome.

Novel magnetic ion-imprinted polymer: an efficient polymeric nanocomposite for selective separation and determination of Pb ions in aqueous media.

A novel ion-imprinted polymer (IIP) toward Pb(II) recognition was synthesized on the surface of magnetic multi-walled carbon nanotubes (magnetic MWCNTs). In order to prepare magnetic functionalized-MWCNT/IIP (magnetic f-MWCNT/IIP), copolymerization of methylenebisacrylamide (MBAm) and acrylamide (AM) in the presence of dithizone-Pb(II) complex was carried out on the surface of the magnetic f-MWCNTs. Selectivity of the new synthesized sorbent toward Pb(II) and the influence of a variety of foreign ions on the recognition, preconcentration, and removal of Pb(II) were evaluated using adsorption experiments in aqueous solution. The synthesized sorbent exhibited a good affinity with high adsorption capacity (Q = 80.81 mg/g) and an excellent selectivity toward Pb(II) in comparison with other common cations including alkaline, alkaline earth, and transition metals such as Na+, K+, Mg2+, Ca2+, Cd2+, and Ni2+. The parameters such as adsorption and desorption time, adsorption capacity, effect of the sorbent mass, eluent type, concentration and volume, and also pH of the solutions were investigated. The result demonstrated that the proposed sorbent provided a fast removal and higher maximum binding capacity compared to other reported synthesized sorbents. The characteristics of the magnetic f-MWCNT/IIP were analyzed using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), vibrating sample magnetometer (VSM), and elemental analysis (EA). Graphical abstract ᅟ.