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15 pages, 3329 KiB

Open AccessArticle

Synthesis and Self-Assembly of Hyperbranched Multiarm Copolymer Lysozyme Conjugates Based on Light-Induced Metal-Free Atrp

by Jianguo Yi, Yan Qin and Yue Zhang

Nanomaterials 2023, 13(6), 1017; https://doi.org/10.3390/nano13061017 - 11 Mar 2023

Cited by 2 | Viewed by 1371

Abstract

In recent years, the coupling of structurally and functionally controllable polymers with biologically active protein materials to obtain polymer–protein conjugates with excellent overall properties and good biocompatibility has been important research in the field of polymers. In this study, the hyperbranched polymer hP(DEGMA- [...] Read more.

In recent years, the coupling of structurally and functionally controllable polymers with biologically active protein materials to obtain polymer–protein conjugates with excellent overall properties and good biocompatibility has been important research in the field of polymers. In this study, the hyperbranched polymer hP(DEGMA-co-OEGMA) was first prepared by combining self-condensation vinyl polymerization (SCVP) with photo-induced metal-free atom transfer radical polymerization (ATRP), with 2-(2-bromo-2-methylpropanoyloxy) ethyl methacrylate (BMA) as inimer, and Di (ethylene glycol) methyl ether methacrylate (DEGMA) and (oligoethylene glycol) methacrylate (OEGMA, M_n = 300) as the copolymer monomer. Then, hP(DEGMA-co-OEGMA) was used as a macroinitiator to continue the polymerization of a segment of pyridyl disulfide ethyl methacrylate (DSMA) monomer to obtain the hyperbranched multiarm copolymers hP(DEGMA-co-OEGMA)-star-PDSMA. Finally, the lysozyme with sulfhydryl groups was affixed to the hyperbranched multiarm copolymers by the exchange reaction between sulfhydryl groups and disulfide bonds to obtain the copolymer protein conjugates hP(DEGMA-co-OEGMA)-star-PLZ. Three hyperbranched multiarm copolymers with relatively close molecular weights but different degrees of branching were prepared, and all three conjugates could self-assemble to form nanoscale vesicle assemblies with narrow dispersion. The biological activity and secondary structure of lysozyme on the assemblies remained essentially unchanged. Full article

(This article belongs to the Special Issue Polymer-Reinforced Multifunctional Nanocomposites and Applications)

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13 pages, 4145 KiB

Open AccessArticle

Highly Porous Carbon Aerogels for High-Performance Supercapacitor Electrodes

by Jong-Hoon Lee, Seul-Yi Lee and Soo-Jin Park

Nanomaterials 2023, 13(5), 817; https://doi.org/10.3390/nano13050817 - 23 Feb 2023

Cited by 3 | Viewed by 2269

Abstract

In recent years, porous carbon materials with high specific surface area and porosity have been developed to meet the commercial demands of supercapacitor applications. Carbon aerogels (CAs) with three-dimensional porous networks are promising materials for electrochemical energy storage applications. Physical activation using gaseous [...] Read more.

In recent years, porous carbon materials with high specific surface area and porosity have been developed to meet the commercial demands of supercapacitor applications. Carbon aerogels (CAs) with three-dimensional porous networks are promising materials for electrochemical energy storage applications. Physical activation using gaseous reagents provides controllable and eco-friendly processes due to homogeneous gas phase reaction and removal of unnecessary residue, whereas chemical activation produced wastes. In this work, we have prepared porous CAs activated by gaseous carbon dioxide, with efficient collisions between the carbon surface and the activating agent. Prepared CAs display botryoidal shapes resulting from aggregation of spherical carbon particles, whereas activated CAs (ACAs) display hollow space and irregular particles from activation reactions. ACAs have high specific surface areas (2503 m² g⁻¹) and large total pore volumes (1.604 cm³ g⁻¹), which are key factors for achieving a high electrical double-layer capacitance. The present ACAs achieved a specific gravimetric capacitance of up to 89.1 F g⁻¹ at a current density of 1 A g⁻¹, along with a high capacitance retention of 93.2% after 3000 cycles. Full article

(This article belongs to the Special Issue Polymer-Reinforced Multifunctional Nanocomposites and Applications)

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15 pages, 2773 KiB

Open AccessArticle

Improved Mechanical Strength of Dicatechol Crosslinked MXene Films for Electromagnetic Interference Shielding Performance

by Soyeon Kim, Canh Minh Vu, Suehyeun Kim, Insik In and Jihoon Lee

Nanomaterials 2023, 13(5), 787; https://doi.org/10.3390/nano13050787 - 21 Feb 2023

Cited by 5 | Viewed by 1782

Abstract

Pristine MXene films express outstanding excellent electromagnetic interference (EMI) shielding properties. Nevertheless, the poor mechanical properties (weak and brittle nature) and easy oxidation of MXene films hinder their practical applications. This study demonstrates a facile strategy for simultaneously improving the mechanical flexibility and [...] Read more.

Pristine MXene films express outstanding excellent electromagnetic interference (EMI) shielding properties. Nevertheless, the poor mechanical properties (weak and brittle nature) and easy oxidation of MXene films hinder their practical applications. This study demonstrates a facile strategy for simultaneously improving the mechanical flexibility and the EMI shielding of MXene films. In this study, dicatechol-6 (DC), a mussel-inspired molecule, was successfully synthesized in which DC as mortars was crosslinked with MXene nanosheets (MX) as bricks to create the brick-mortar structure of the MX@DC film. The resulting MX@DC-2 film has a toughness of 40.02 kJ·m⁻³ and Young’s modulus of 6.2 GPa, which are improvements of 513% and 849%, respectively, compared to those of the bare MXene films. The coating of electrically insulating DC significantly reduced the in-plane electrical conductivity from 6491 S·cm⁻¹ for the bare MXene film to 2820 S·cm⁻¹ for the MX@DC-5 film. However, the EMI shielding effectiveness (SE) of the MX@DC-5 film reached 66.2 dB, which is noticeably greater than that of the bare MX film (61.5 dB). The enhancement in EMI SE resulted from the highly ordered alignment of the MXene nanosheets. The synergistic concurrent enhancement in the strength and EMI SE of the DC-coated MXene film can facilitate the utilization of the MXene film in reliable, practical applications. Full article

(This article belongs to the Special Issue Polymer-Reinforced Multifunctional Nanocomposites and Applications)

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14 pages, 8657 KiB

Open AccessArticle

Amphiphilic Bowl-Shaped Janus Particles Prepared via Thiol–Ene Click Reaction for Effective Oil–Water Separation

by Xian Qi, Yaxian Du, Ziqiang Zhang and Xu Zhang

Nanomaterials 2023, 13(3), 455; https://doi.org/10.3390/nano13030455 - 22 Jan 2023

Cited by 2 | Viewed by 1292

Abstract

Janus particles for oil–water separation have attracted widespread attention in recent years. Herein, we prepared a bowl-shaped Janus particle that could rapidly separate oil and water through a thiol–ene click reaction and selective etching. Firstly, snowman-like composite microspheres based on silica and mercaptopropyl [...] Read more.

Janus particles for oil–water separation have attracted widespread attention in recent years. Herein, we prepared a bowl-shaped Janus particle that could rapidly separate oil and water through a thiol–ene click reaction and selective etching. Firstly, snowman-like composite microspheres based on silica and mercaptopropyl polysilsesquioxane (SiO₂@MPSQ) were prepared by a hydrolytic condensation reaction and phase separation, and the effects of the rotational speed and molar ratios on their microscopic morphologies were investigated. Subsequently, bowl-shaped Janus particles with convex hydrophilic and concave oleophilic surfaces were prepared via a thiol–ene click reaction followed by HF etching. Our amphiphilic bowl-shaped Janus particles could remarkably separate micro-sized oil droplets from an n-heptane–water emulsion with a separation efficiency of >98% within 300 s. Based on the experimental and theoretical results, we proposed the underlying mechanism for the coalescence of oil droplets upon the addition of the amphiphilic bowl-shaped Janus particles. Full article

(This article belongs to the Special Issue Polymer-Reinforced Multifunctional Nanocomposites and Applications)

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13 pages, 3424 KiB

Open AccessArticle

Effect of Ambient Plasma Treatments on Thermal Conductivity and Fracture Toughness of Boron Nitride Nanosheets/Epoxy Nanocomposites

by Won-Jong Choi, Seul-Yi Lee and Soo-Jin Park

Nanomaterials 2023, 13(1), 138; https://doi.org/10.3390/nano13010138 - 27 Dec 2022

Cited by 5 | Viewed by 1739

Abstract

With the rapid growth in the miniaturization and integration of modern electronics, the dissipation of heat that would otherwise degrade the device efficiency and lifetime is a continuing challenge. In this respect, boron nitride nanosheets (BNNS) are of significant attraction as fillers for [...] Read more.

With the rapid growth in the miniaturization and integration of modern electronics, the dissipation of heat that would otherwise degrade the device efficiency and lifetime is a continuing challenge. In this respect, boron nitride nanosheets (BNNS) are of significant attraction as fillers for high thermal conductivity nanocomposites due to their high thermal stability, electrical insulation, and relatively high coefficient of thermal conductivity. Herein, the ambient plasma treatment of BNNS (PBNNS) for various treatment times is described for use as a reinforcement in epoxy nanocomposites. The PBNNS-loaded epoxy nanocomposites are successfully manufactured in order to investigate the thermal conductivity and fracture toughness. The results indicate that the PBNNS/epoxy nanocomposites subjected to 7 min plasma treatment exhibit the highest thermal conductivity and fracture toughness, with enhancements of 44 and 110%, respectively, compared to the neat nanocomposites. With these enhancements, the increases in surface free energy and wettability of the PBNNS/epoxy nanocomposites are shown to be attributable to the enhanced interfacial adhesion between the filler and matrix. It is demonstrated that the ambient plasma treatments enable the development of highly dispersed conductive networks in the PBNNS epoxy system. Full article

(This article belongs to the Special Issue Polymer-Reinforced Multifunctional Nanocomposites and Applications)

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20 pages, 8514 KiB

Open AccessArticle

Multifunctional Waterborne Polyurethane Microreactor-Based Approach to Fluorocarbon Composite Latex Coatings with Double Self-Healing and Excellent Synergistic Performances

by Chao Li, Huimin Guo, Ning Zhang, Yao Jin, Kai Han, Jinfeng Yuan, Zhicheng Pan and Mingwang Pan

Nanomaterials 2022, 12(23), 4216; https://doi.org/10.3390/nano12234216 - 27 Nov 2022

Cited by 1 | Viewed by 1095

Abstract

In this article, chlorotrifluoroethylene (CTFE)-based fluorocarbon composite latexes and their coatings are successfully fabricated by an environmentally friendly preparation method based on a new multifunctional waterborne polyurethane (MFWPU) dispersion. It is worth noting that the MFWPU acts as the sole system stabilizer as [...] Read more.

In this article, chlorotrifluoroethylene (CTFE)-based fluorocarbon composite latexes and their coatings are successfully fabricated by an environmentally friendly preparation method based on a new multifunctional waterborne polyurethane (MFWPU) dispersion. It is worth noting that the MFWPU acts as the sole system stabilizer as well as microreactor and simultaneously endows the composite coating with excellent double self-healing performance and adhesion. Moreover, the introduction of a dynamic disulfide bond in the polyurethane dispersion entrusts the coating with excellent scratch self-healing performance. Simultaneously, carbon–carbon double bonds in the polyurethane dispersion increase the compatibility between the core polymer and shell polymer. The fluorine-containing chain segments can be distributed in the coating evenly during the self-assembly film-forming process of composite particles so that the original element composition of the worn coating surface can restore the original element composition after heating, and the coating presents a regeneration ability, which further and verifies the usefulness of the double self-healing model of the coating. Afterward, efficient recovery and durability, which are two contradictory properties of scratch self-healing polymers, are optimized to obtain a composite coating with excellent comprehensive performance. The research results regarding the composite system may provide a valuable reference for the structural design and application of waterborne fluorocarbon functional coatings in the future. Full article

(This article belongs to the Special Issue Polymer-Reinforced Multifunctional Nanocomposites and Applications)

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14 pages, 3517 KiB

Open AccessArticle

Rational Design of Fluorinated Phthalonitrile/Hollow Glass Microsphere Composite with Low Dielectric Constant and Excellent Heat Resistance for Microelectronic Packaging

by Minjie Wu, Wenshuang Han, Chun Zhang, Shuo Zhang, Xinyang Zhang, Xinggang Chen, Kimiyoshi Naito, Xiaoyan Yu and Qingxin Zhang

Nanomaterials 2022, 12(22), 3973; https://doi.org/10.3390/nano12223973 - 11 Nov 2022

Cited by 6 | Viewed by 1474

Abstract

High-performance composites with a resin matrix are urgently required for electronic packaging due to their low dielectric constant, outstanding high temperature resistance, excellent corrosion resistance, light weight and easy molding. In this work, hollow-glass-microsphere (HGM)-filled fluorinated-phthalonitrile (PBDP) composites, with filler contents ranging from [...] Read more.

High-performance composites with a resin matrix are urgently required for electronic packaging due to their low dielectric constant, outstanding high temperature resistance, excellent corrosion resistance, light weight and easy molding. In this work, hollow-glass-microsphere (HGM)-filled fluorinated-phthalonitrile (PBDP) composites, with filler contents ranging from 0 to 35.0 vol.%, were prepared in order to modify the dielectric properties of the phthalonitrile. Scanning electron microscopy (SEM) observations indicate that the modified HGM particles were uniformly dispersed in the matrix. The PBDP/27.5HGM-NH₂ composite demonstrates a low dielectric constant of 1.85 at 12 GHz. The 5% thermogravimetric temperature (T₅) of composites with silanized HGM filler (481–486 °C) is higher than the minimum packaging-material requirements (450 °C). In addition, the heat-resistance index (T_HRI) of PBDP/HGM-NH₂ composites reached as high as 268 °C. the storage modulus of PBDP/HGM-NH₂ composites were significantly increased to 1283 MPa at 400 °C, an increase by 50%, in comparison to that of PBDP phthalonitrile resin (857 MPa). The excellent dielectric and thermal properties of the present composites may pave a way for comprehensive applications in electronic packaging and thermal management for energy systems. Full article

(This article belongs to the Special Issue Polymer-Reinforced Multifunctional Nanocomposites and Applications)

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10 pages, 3413 KiB

Open AccessEditor’s ChoiceArticle

Fabrication, Thermal Conductivity, and Mechanical Properties of Hexagonal-Boron-Nitride-Pattern-Embedded Aluminum Oxide Composites

by Hyesun Yun, Min-Gi Kwak, KeumHwan Park and Youngmin Kim

Nanomaterials 2022, 12(16), 2815; https://doi.org/10.3390/nano12162815 - 16 Aug 2022

Cited by 2 | Viewed by 1814

Abstract

As electronics become more portable and compact, the demand for high-performance thermally conductive composites is increasing. Given that the thermal conductivity correlates with the content of thermally conductive fillers, it is important to fabricate composites with high filler loading. However, the increased viscosity [...] Read more.

As electronics become more portable and compact, the demand for high-performance thermally conductive composites is increasing. Given that the thermal conductivity correlates with the content of thermally conductive fillers, it is important to fabricate composites with high filler loading. However, the increased viscosity of the composites upon the addition of these fillers impedes the fabrication of filler-reinforced composites through conventional methods. In this study, hexagonal-boron-nitride (h-BN)-pattern-embedded aluminum oxide (Al₂O₃) composites (Al/h-BN/Al composites) were fabricated by coating a solution of h-BN onto a silicone-based Al₂O₃ composite through a metal mask with square open areas. Because this method does not require the dispersion of h-BN into the Al₂O₃ composite, composites with high filler loading could be fabricated without the expected problems arising from increased viscosity. Based on the coatability and thixotropic rheological behaviors, a composite with 85 wt.% Al₂O₃ was chosen to fabricate Al/h-BN/Al composites. The content of the Al₂O₃ and the h-BN of the Al/h-BN/Al-1 composite was 74.1 wt.% and 12.8 wt.%, respectively. In addition to the increased filler content, the h-BN of the composite was aligned in a parallel direction by hot pressing. The in-plane (k_x) and through-plane (k_z) thermal conductivity of the composite was measured as 4.99 ± 0.15 Wm⁻¹ K⁻¹ and 1.68 ± 0.2 Wm⁻¹ K⁻¹, respectively. These results indicated that the method used in this study is practical not only for increasing the filler loading but also for achieving a high k_x through the parallel alignment of h-BN fillers. Full article

(This article belongs to the Special Issue Polymer-Reinforced Multifunctional Nanocomposites and Applications)

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16 pages, 3286 KiB

Open AccessArticle

Effective Conductivity of Carbon-Nanotube-Filled Systems by Interfacial Conductivity to Optimize Breast Cancer Cell Sensors

by Yasser Zare, Kyong-Yop Rhee and Soo-Jin Park

Nanomaterials 2022, 12(14), 2383; https://doi.org/10.3390/nano12142383 - 12 Jul 2022

Viewed by 1143

Abstract

Interfacial conductivity and “L_c”, i.e., the least carbon-nanotube (CNT) length required for the operative transfer of CNT conductivity to the insulated medium, were used to establish the most effective CNT concentration and portion of CNTs needed for a network structure [...] Read more.

Interfacial conductivity and “L_c”, i.e., the least carbon-nanotube (CNT) length required for the operative transfer of CNT conductivity to the insulated medium, were used to establish the most effective CNT concentration and portion of CNTs needed for a network structure in polymer CNT nanocomposites (PCNT). The mentioned parameters and tunneling effect define the effective conductivity of PCNT. The impact of the parameters on the beginning of percolation, the net concentration, and the effective conductivity of PCNT was investigated and the outputs were explained. Moreover, the calculations of the beginning of percolation and the conductivity demonstrate that the experimental results and the developed equations are in acceptable agreement. A small “L_c” and high interfacial conductivity affect the beginning of percolation, the fraction of networked CNTs, and the effective conductivity. Additionally, a low tunneling resistivity, a wide contact diameter, and small tunnels produce a highly effective conductivity. The developed model can be used to optimize breast cancer cell sensors. Full article

(This article belongs to the Special Issue Polymer-Reinforced Multifunctional Nanocomposites and Applications)

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Review

Jump to: Research

36 pages, 6569 KiB

Open AccessFeature PaperReview

Recent Advanced Supercapacitor: A Review of Storage Mechanisms, Electrode Materials, Modification, and Perspectives

by Niraj Kumar, Su-Bin Kim, Seul-Yi Lee and Soo-Jin Park

Nanomaterials 2022, 12(20), 3708; https://doi.org/10.3390/nano12203708 - 21 Oct 2022

Cited by 62 | Viewed by 9432

Abstract

In recent years, the development of energy storage devices has received much attention due to the increasing demand for renewable energy. Supercapacitors (SCs) have attracted considerable attention among various energy storage devices due to their high specific capacity, high power density, long cycle [...] Read more.

In recent years, the development of energy storage devices has received much attention due to the increasing demand for renewable energy. Supercapacitors (SCs) have attracted considerable attention among various energy storage devices due to their high specific capacity, high power density, long cycle life, economic efficiency, environmental friendliness, high safety, and fast charge/discharge rates. SCs are devices that can store large amounts of electrical energy and release it quickly, making them ideal for use in a wide range of applications. They are often used in conjunction with batteries to provide a power boost when needed and can also be used as a standalone power source. They can be used in various potential applications, such as portable equipment, smart electronic systems, electric vehicles, and grid energy storage systems. There are a variety of materials that have been studied for use as SC electrodes, each with its advantages and limitations. The electrode material must have a high surface area to volume ratio to enable high energy storage densities. Additionally, the electrode material must be highly conductive to enable efficient charge transfer. Over the past several years, several novel materials have been developed which can be used to improve the capacitance of the SCs. This article reviews three types of SCs: electrochemical double-layer capacitors (EDLCs), pseudocapacitors, and hybrid supercapacitors, their respective development, energy storage mechanisms, and the latest research progress in material preparation and modification. In addition, it proposes potentially feasible solutions to the problems encountered during the development of supercapacitors and looks forward to the future development direction of SCs. Full article

(This article belongs to the Special Issue Polymer-Reinforced Multifunctional Nanocomposites and Applications)

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