Polymers

Research

Jump to: Review

10 pages, 3522 KiB

Open AccessArticle

Flexible PDMS-Based SERS Substrates Replicated from Beetle Wings for Water Pollutant Detection

by Chen-Hsin Lu, Ming-Ren Cheng, Sheng Chen, Wei-Lin Syu, Ming-Yen Chien, Kuan-Syun Wang, Jeng-Shiung Chen, Po-Han Lee and Ting-Yu Liu

Polymers 2023, 15(1), 191; https://doi.org/10.3390/polym15010191 - 30 Dec 2022

Cited by 8 | Viewed by 3159

Abstract

The flexible surface-enhanced Raman scattering (SERS) sensor, which has the bionic 3D nanoarray structure of a beetle-wing substrate (BWS), was successfully prepared by replicated technology and thermal evaporation. The bionic structure was replicated with polydimethylsiloxane (PDMS) and then silver (Ag) nanoisland thin films [...] Read more.

The flexible surface-enhanced Raman scattering (SERS) sensor, which has the bionic 3D nanoarray structure of a beetle-wing substrate (BWS), was successfully prepared by replicated technology and thermal evaporation. The bionic structure was replicated with polydimethylsiloxane (PDMS) and then silver (Ag) nanoisland thin films were deposited by thermal evaporation. The deposition times and thicknesses (25–40 nm) of the Ag thin films were manipulated to find the optimal SERS detection capability. The Ag nanoisland arrays on the surface of the bionic replicated PDMS were observed by scanning electron microscope (SEM), X-ray diffraction (XRD), and contact angle, which can generate strong and reproducible three-dimensional hotspots (3D hotspots) to enhance Raman signals. The water pollutant, rhodamine 6G (R6G), was used as a model molecule for SERS detection. The results show that 35 nm Ag deposited on a PDMS-BWS SERS substrate displays the strongest SERS intensity, which is 10 times higher than that of the pristine BWS with 35 nm Ag coating, due to the excellent 3D bionic structure. Our results demonstrate that bionic 3D SERS sensors have the potential to be applied in wearable devices and sensors to detect biomolecules and environmental pollutants, such as industrial wastewater, in the future. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Figure 1

14 pages, 7863 KiB

Open AccessArticle

Self-Assembled Supramolecular Micelles Based on Multiple Hydrogen Bonding Motifs for the Encapsulation and Release of Fullerene

by Cheng-Wei Huang, Ya-Ying Chang, Chih-Chia Cheng, Meng-Ting Hung and Mohamed Gamal Mohamed

Polymers 2022, 14(22), 4923; https://doi.org/10.3390/polym14224923 - 15 Nov 2022

Cited by 2 | Viewed by 1800

Abstract

Living creatures involve several defense mechanisms, such as protecting enzymes to protect organs and cells from the invasion of free radicals. Developing antioxidant molecules and delivery systems to working with enzymes is vital. In this study, a supramolecular polymer PNI-U-DPy was used to [...] Read more.

Living creatures involve several defense mechanisms, such as protecting enzymes to protect organs and cells from the invasion of free radicals. Developing antioxidant molecules and delivery systems to working with enzymes is vital. In this study, a supramolecular polymer PNI-U-DPy was used to encapsulate C₆₀, a well-known antioxidant that is hard to dissolve or disperse in the aqueous media. PNI-U-DPy exhibits characteristics similar to PNIPAM but could form micelles even when the environment temperature is lower than its LCST. The U-DPy moieties could utilize their strong complementary hydrogen bonding–interaction to create a physically crosslinked network within PNIPAM micelles, thus adjusting its LCST to a value near the physiological temperature. Morphological studies suggested that C₆₀ could be effectively loaded into PNI-U-DPy micelles with a high loading capacity (29.12%), and the resulting complex PNI-C₆₀ is stable and remains temperature responsive. A series of measurements under variable temperatures was carried out and showed that a controlled release process proceeded. Furthermore, PNI-C₆₀ exhibits hydroxyl radicals scavenging abilities at a low dosage and could even be adjusted by temperature. It can be admitted that the micelle system can be a valuable alternative for radical scavengers and may be delivered to the desired position with good dispersibility and thermo-responsivity. It is beneficial to the search progress of scientists for drug delivery systems for chemotherapeutic treatments and biomedical applications. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Figure 1

14 pages, 4954 KiB

Open AccessArticle

Enhanced Thermal Stability of Mesoporous Carbon Microbeads-Based Lithium-Ion Batteries by Propargyl Methacrylate as Electrolyte Additive

by Yu-Ruei Kung, Jing-Tang Su, Chiung-Cheng Huang, Yaoming Xiao and Jeng-Yu Lin

Polymers 2022, 14(21), 4491; https://doi.org/10.3390/polym14214491 - 24 Oct 2022

Cited by 2 | Viewed by 1861

Abstract

In this current work, propargyl methacrylate (PMA) was successfully adopted to be an efficient electrolyte additive to stabilize the formation of a solid electrolyte interface (SEI) layer on mesoporous carbon microbeads (MCMB) in Li-ion batteries, especially at elevated temperatures. According to a series [...] Read more.

In this current work, propargyl methacrylate (PMA) was successfully adopted to be an efficient electrolyte additive to stabilize the formation of a solid electrolyte interface (SEI) layer on mesoporous carbon microbeads (MCMB) in Li-ion batteries, especially at elevated temperatures. According to a series of material and electrochemical characterizations, the optimized concentration of PMA additive in the electrolyte was found to be 0.5 wt.%. The MCMB electrode cycled with the optimized 0.5 wt.% PMA-containing electrolyte exhibited impressive capacity retention of 90.3% after 50 cycles at 0.1C at elevated temperature, which was remarkably higher than that using the PMA-free electrolyte (83.5%). The improved electrochemical stability at elevated temperature could be ascribed to the rapid formation of stable and thin SEI layer on MCMB surface, which were investigated and suggested to be formed via PMA copolymerization reactions. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Figure 1

13 pages, 4138 KiB

Open AccessArticle

Magnetizing Polymer Particles with a Solvent-Free Single Stage Process Using Superparamagnetic Iron Oxide Nanoparticles (SPION)s

by Björn Düsenberg, Philipp Groppe, Stephan Müssig, Jochen Schmidt and Andreas Bück

Polymers 2022, 14(19), 4178; https://doi.org/10.3390/polym14194178 - 5 Oct 2022

Cited by 4 | Viewed by 2219

Abstract

Magnetic polymer composites are used in a variety of applications in many industries. Their production methods are usually time-consuming and solvent-intensive as they are performed in liquid phase processes, such as emulsion polymerization or precipitation. In this work, a quick, easy, and solvent-free [...] Read more.

Magnetic polymer composites are used in a variety of applications in many industries. Their production methods are usually time-consuming and solvent-intensive as they are performed in liquid phase processes, such as emulsion polymerization or precipitation. In this work, a quick, easy, and solvent-free method is presented to coat polymer particles with a discrete, non-coherent coating of superparamagnetic nanoparticles. The results of the dry coating process are evaluated optically, by means of scanning electron microscopy (SEM), via powder X-ray diffraction and thermally by means of differential scanning calorimetry, before finally demonstrating the effectiveness of dry coating by means of a vibrating sample magnetometer. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Figure 1

15 pages, 3092 KiB

Open AccessFeature PaperArticle

Nonwoven Mats Based on Segmented Biopolyurethanes Filled with MWCNT Prepared by Solution Blow Spinning

by Pablo Ramos, Tamara Calvo-Correas, Arantxa Eceiza and Javier González-Benito

Polymers 2022, 14(19), 4175; https://doi.org/10.3390/polym14194175 - 5 Oct 2022

Cited by 2 | Viewed by 1855

Abstract

To prepare nonwoven mats constituted by submicrometric fibers of thermally responsive biopolyurethanes (TPU) modified with multiwalled carbon nanotubes (MWCNT), solution blow spinning (SBS) was used. The TPU was the product of synthesis using poly(butylene sebacate)diol, PBSD, ethyl ester L-lysine diisocyanate (LDI), and 1,3-propanediol [...] Read more.

To prepare nonwoven mats constituted by submicrometric fibers of thermally responsive biopolyurethanes (TPU) modified with multiwalled carbon nanotubes (MWCNT), solution blow spinning (SBS) was used. The TPU was the product of synthesis using poly(butylene sebacate)diol, PBSD, ethyl ester L-lysine diisocyanate (LDI), and 1,3-propanediol (PD) (PBSe:LDI:PD) as reactants. TPU was modified by adding different amounts of MWCNT (0, 0.5, 1, 2, and 3 wt.%). The effect of the presence and amount of MWCNT on the morphology and structure of the materials was studied using field-emission scanning electron microscopy (FESEM) and Fourier-transform infrared spectroscopy (FTIR), respectively, while their influence on the thermal and electric behaviors was studied using differential scanning calorimetry (DSC) and capacitance measurements, respectively. The addition of MWCNT by SBS induced morphological changes in the fibrous materials, affecting the relative amount and size of submicrometric fibers and, therefore, the porosity. As the MWCNT content increased, the diameter of the fibers increased and their relative amount with respect to all morphological microfeatures increased, leading to a more compact microstructure with lower porosity. The highly porous fibrous morphology of TPU-based materials achieved by SBS allowed turning a hydrophilic material to a highly hydrophobic one. Percolation of MWCNT was attained between 2 and 3 wt.%, affecting not only the electric properties of the materials but also their thermal behavior. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Graphical abstract

15 pages, 4177 KiB

Open AccessArticle

New Hybrid Nanocomposites with Catalytic Properties Obtained by In Situ Preparation of Gold Nanoparticles on Poly (Ionic Liquid)/Poly (4-Vinylpyridine) Nanofibers

by Oscar Ramírez, Matías Leal, Ximena Briones, Marcela Urzúa, Sebastián Bonardd, Cesar Saldías and Angel Leiva

Polymers 2022, 14(18), 3782; https://doi.org/10.3390/polym14183782 - 9 Sep 2022

Cited by 2 | Viewed by 1930

Abstract

In this work, we report the obtaining of new hybrid nanocomposites with catalytic activity formed by nanofibers of polymer blends and gold nanoparticles. The nanofibers were obtained by electrospinning blends of a poly (ionic liquid) (PIL) and its precursor polymer, poly (4-vinyl pyridine) [...] Read more.

In this work, we report the obtaining of new hybrid nanocomposites with catalytic activity formed by nanofibers of polymer blends and gold nanoparticles. The nanofibers were obtained by electrospinning blends of a poly (ionic liquid) (PIL) and its precursor polymer, poly (4-vinyl pyridine) (P4VPy). The characteristics of the nanofibers obtained proved to be dependent on the proportion of polymer in the blends. The nanofibers obtained were used to synthesize, in situ, gold nanoparticles on their surface by two-step procedure. Firstly, the adsorption of precursor ions on the nanofibers and then their reduction with sodium borohydride to generate gold nanoparticles. The results indicated a significant improvement in the performance of PIL-containing nanofibers over pure P4VPy NFs during ion adsorption, reaching a 20% increase in the amount of adsorbed ions and a 6-fold increase in the respective adsorption constant. The catalytic performance of the obtained hybrid systems in the reduction reaction of 4-nitrophenol to 4-aminophenol was studied. Higher catalytic conversions were obtained using the hybrid nanofibers containing PIL and gold nanoparticles achieving a maximum conversion rate of 98%. Remarkably, the highest value of kinetic constant was obtained for the nanofibers with the highest PIL content. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Graphical abstract

16 pages, 4650 KiB

Open AccessArticle

A Comparative Study on X-ray Shielding and Mechanical Properties of Natural Rubber Latex Nanocomposites Containing Bi₂O₃ or BaSO₄: Experimental and Numerical Determination

by Arkarapol Thumwong, Manchusa Chinnawet, Preawpraw Intarasena, Chanis Rattanapongs, Shinji Tokonami, Tetsuo Ishikawa and Kiadtisak Saenboonruang

Polymers 2022, 14(17), 3654; https://doi.org/10.3390/polym14173654 - 2 Sep 2022

Cited by 18 | Viewed by 1942

Abstract

This work experimentally determined the X-ray shielding and morphological, density, and tensile properties of sulfur-vulcanized natural rubber latex (SVNRL) nanocomposites containing varying content of nano-Bi₂O₃ or nano-BaSO₄ from 0 to 200 phr in 100 phr increments, with modified procedures [...] Read more.

This work experimentally determined the X-ray shielding and morphological, density, and tensile properties of sulfur-vulcanized natural rubber latex (SVNRL) nanocomposites containing varying content of nano-Bi₂O₃ or nano-BaSO₄ from 0 to 200 phr in 100 phr increments, with modified procedures in sample preparation to overcome the insufficient strength of the samples found in other reports. The experimental X-ray shielding results, which were numerically verified using a web-based software package (XCOM), indicated that the overall X-ray attenuation abilities of the SVNRL nanocomposites generally increased with increasing filler content, with the 0.25-mm-thick SVNRL films containing 200 phr of the filler providing the highest overall X-ray shielding properties, as evidenced by the highest values of lead equivalence (Pb_eq) of 0.0371 mmPb and 0.0326 mmPb in Bi₂O₃/SVNRL nanocomposites, and 0.0326 mmPb and 0.0257 mmPb in BaSO₄/SVNRL nanocomposites, for 60 kV and 100 kV X-rays, respectively. The results also revealed that the addition of either filler increased the tensile modulus at 300% elongation (M300) and density but decreased the tensile strength and the elongation at break of the Bi₂O₃/SVNRL and BaSO₄/SVNRL nanocomposites. In addition, the modified procedures introduced in this work enabled the developed nanocomposites to acquire sufficient mechanical and X-ray shielding properties for potential use as medical X-ray protective gloves, with the recommended content of Bi₂O₃ and BaSO₄ being in the range of 95–140 phr and 105–120 phr, respectively (in accordance with the requirements outlined in ASTM D3578-19 and the value of Pb_eq being greater than 0.02 mmPb). Consequently, based on the overall outcomes of this work, the developed Bi₂O₃/SVNRL and BaSO₄/SVNRL nanocomposites show great potential for effective application in medical X-ray protective gloves, while the modified procedures could possibly be adopted for large-scale production. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Graphical abstract

20 pages, 8864 KiB

Open AccessArticle

Novel Hybrid Nanomaterials Based on Poly-N-Phenylanthranilic Acid and Magnetic Nanoparticles with Enhanced Saturation Magnetization

by Sveta Zhiraslanovna Ozkan, Aleksandr Ivanovich Kostev, Petr Aleksandrovich Chernavskii and Galina Petrovna Karpacheva

Polymers 2022, 14(14), 2935; https://doi.org/10.3390/polym14142935 - 20 Jul 2022

Cited by 1 | Viewed by 1477

Abstract

A one-step preparation method for cobalt- and iron-containing nanomaterials based on poly-N-phenylanthranilic acid (P-N-PAA) and magnetic nanoparticles (MNP) was developed for the first time. To synthesize the MNP/P-N-PAA nanocomposites, the precursor is obtained by dissolving a Co (II) salt in a [...] Read more.

A one-step preparation method for cobalt- and iron-containing nanomaterials based on poly-N-phenylanthranilic acid (P-N-PAA) and magnetic nanoparticles (MNP) was developed for the first time. To synthesize the MNP/P-N-PAA nanocomposites, the precursor is obtained by dissolving a Co (II) salt in a magnetic fluid based on Fe₃O₄/P-N-PAA with a core-shell structure. During IR heating of the precursor in an inert atmosphere at T = 700–800 °C, cobalt interacts with Fe₃O₄ reduction products, which results in the formation of a mixture of spherical Co-Fe, γ-Fe, β-Co and Fe₃C nanoparticles of various sizes in the ranges of 20 < d < 50 nm and 120 < d < 400 nm. The phase composition of the MNP/P-N-PAA nanocomposites depends significantly on the cobalt concentration. The reduction of metals occurs due to the hydrogen released during the dehydrogenation of phenylenamine units of the polymer chain. The introduction of 10–30 wt% cobalt in the composition of nanocomposites leads to a significant increase in the saturation magnetization of MNP/P-N-PAA (M_S = 81.58–149.67 emu/g) compared to neat Fe₃O₄/P-N-PAA (M_S = 18.41–27.58 emu/g). The squareness constant of the hysteresis loop is κ_S = M_R/M_S = 0.040–0.209. The electrical conductivity of the MNP/P-N-PAA nanomaterials does not depend much on frequency and reaches 1.2 × 10⁻¹ S/cm. In the argon flow at 1000 °C, the residue is 77–88%. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Graphical abstract

13 pages, 34352 KiB

Open AccessArticle

Nonlinear Conductivity and Space Charge Characteristics of SiC/Silicone Rubber Nanocomposites

by Ming-Ze Gao, Zhong-Yuan Li and Wei-Feng Sun

Polymers 2022, 14(13), 2726; https://doi.org/10.3390/polym14132726 - 3 Jul 2022

Cited by 4 | Viewed by 2279

Abstract

To achieve a preferable compatibility between liquid silicone rubber (LSR) and cable main insulation in a cable accessory, we developed SiC/LSR nanocomposites with a significantly higher conductivity nonlinearity than pure LSR, whilst representing a notable improvement in space charge characteristics. Space charge distributions [...] Read more.

To achieve a preferable compatibility between liquid silicone rubber (LSR) and cable main insulation in a cable accessory, we developed SiC/LSR nanocomposites with a significantly higher conductivity nonlinearity than pure LSR, whilst representing a notable improvement in space charge characteristics. Space charge distributions in polarization/depolarization processes and surface potentials of SiC/LSR composites are analyzed to elucidate the percolation conductance and charge trapping mechanisms accounting for nonlinear conductivity and space charge suppression. It is verified that SiC/LSR composites with SiC content higher than 10 wt% represent an evident nonlinearity of electric conductivity as a function of the electric field strength. Space charge accumulations can be inhibited by filling SiC nanoparticles into LSR, as illustrated in both dielectric polarization and depolarization processes. Energy level and density of shallow traps increase significantly with SiC content, which accounts for expediting carrier hopping transport and surface charge decay. Finite-element multiphysics simulations demonstrate that nonlinear conductivity acquired by 20 wt% SiC/LSR nanocomposite could efficiently homogenize an electric field distributed in high-voltage direct current (HVDC) cable joints. Nonlinear conductivities and space charge characteristics of SiC/LSR composites discussed in this paper suggest a feasible modification strategy to improve insulation performances of direct current (DC) cable accessories. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Figure 1

14 pages, 5707 KiB

Open AccessArticle

Replica of Bionic Nepenthes Peristome-like and Anti-Fouling Structures for Self-Driving Water and Raman-Enhancing Detection

by Yen-Ting Lin, Chun-Hao Wu, Wei-Lin Syu, Po-Cheng Ho, Zi-Ling Tseng, Ming-Chien Yang, Chin-Ching Lin, Cheng-Chen Chen, Cheng-Cheung Chen and Ting-Yu Liu

Polymers 2022, 14(12), 2465; https://doi.org/10.3390/polym14122465 - 17 Jun 2022

Cited by 7 | Viewed by 2669

Abstract

The flexible, anti-fouling, and bionic surface-enhanced Raman scattering (SERS) biochip, which has a Nepenthes peristome-like structure, was fabricated by photolithography, replicated technology, and thermal evaporation. The pattern of the bionic Nepenthes peristome-like structure was fabricated by two layers of photolithography with SU-8 photoresist. [...] Read more.

The flexible, anti-fouling, and bionic surface-enhanced Raman scattering (SERS) biochip, which has a Nepenthes peristome-like structure, was fabricated by photolithography, replicated technology, and thermal evaporation. The pattern of the bionic Nepenthes peristome-like structure was fabricated by two layers of photolithography with SU-8 photoresist. The bionic structure was then replicated by polydimethylsiloxane (PDMS) and grafting the zwitterion polymers (2-methacryloyloxyethyl phosphorylcholine, MPC) by atmospheric plasma polymerization (PDMS-PMPC). The phospholipid monomer of MPC immobilization plays an important role; it can not only improve hydrophilicity, anti-fouling and anti-bacterial properties, and biocompatibility, but it also allows for self-driving and unidirectional water delivery. Ag nanofilms (5 nm) were deposited on a PDMS (PDMS-Ag) substrate by thermal evaporation for SERS detection. Characterizations of the bionic SERS chips were measured by a scanning electron microscope (SEM), optical microscope (OM), X-ray photoelectron spectrometer (XPS), Fourier-transform infrared spectroscopy (FTIR), and contact angle (CA) testing. The results show that the superior anti-fouling capability of proteins and bacteria (E. coli) was found on the PDMS-PMPC substrate. Furthermore, the one-way liquid transfer capability of the bionic SERS chip was successfully demonstrated, which provides for the ability to separate samples during the flow channel, and which was detected by Raman spectroscopy. The SERS intensity (adenine, 10⁻⁴ M) of PDMS-Ag with a bionic structure is ~4 times higher than PDMS-Ag without a bionic structure, due to the multi-reflection of the 3D bionic structure. The high-sensitivity bionic SERS substrate, with its self-driving water capability, has potential for biomolecule separation and detection. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Graphical abstract

11 pages, 4052 KiB

Open AccessArticle

Facile and Green Process to Synthesize a Three-Dimensional Network Few-Layer Graphene/Carbon Nanotube Composite for Electromagnetic Interference Shielding

by Yu-Hong Yeh, Kuei-Ting Hsu, Chia-Hung Huang and Wei-Ren Liu

Polymers 2022, 14(9), 1892; https://doi.org/10.3390/polym14091892 - 5 May 2022

Cited by 2 | Viewed by 1982

Abstract

We propose an environmentally friendly liquid exfoliation approach and subsequent freeze-drying process for constructing a three-dimensional (3D) carbon-based network by using few-layer graphene (FLG) and carbon nanotubes (CNTs) for electromagnetic interference (EMI) shielding applications. Systematic characterizations—such as X-ray diffraction, scanning electron microscopy, and [...] Read more.

We propose an environmentally friendly liquid exfoliation approach and subsequent freeze-drying process for constructing a three-dimensional (3D) carbon-based network by using few-layer graphene (FLG) and carbon nanotubes (CNTs) for electromagnetic interference (EMI) shielding applications. Systematic characterizations—such as X-ray diffraction, scanning electron microscopy, and transmission electron microscopy—as well as Raman characterization and EMI shielding tests were performed. The results indicated that the as-synthesized 3D-FLG/CNT composite obtained through the freeze-drying process exhibited excellent electromagnetic interference shielding. The shielding effect of FLG could be improved from 15 to 22 dB by introducing CNTs. The CNTs inhibited restacking of FLG in the structure. We also compared two drying processes: oven drying and freeze-drying. The freeze-drying technique markedly improved the shielding effect of FLG/CNTs from 22 to 36 dB. The composition-optimized 3D-FLG/CNT composite could be a candidate material for use in EMI shielding. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Graphical abstract

13 pages, 4291 KiB

Open AccessArticle

Nanocomposites of Chitosan/Graphene Oxide/Titanium Dioxide Nanoparticles/Blackberry Waste Extract as Potential Bone Substitutes

by Carlos Humberto Valencia-Llano, Moisés A. Solano and Carlos David Grande-Tovar

Polymers 2021, 13(22), 3877; https://doi.org/10.3390/polym13223877 - 10 Nov 2021

Cited by 10 | Viewed by 2360

Abstract

New technologies based on nanocomposites of biopolymers and nanoparticles inspired by the nature of bone structure have accelerated their application in regenerative medicine, thanks to the introduction of reinforcing properties. Our research incorporated chitosan (CS) covalently crosslinked with glutaraldehyde (GLA) beads with graphene [...] Read more.

New technologies based on nanocomposites of biopolymers and nanoparticles inspired by the nature of bone structure have accelerated their application in regenerative medicine, thanks to the introduction of reinforcing properties. Our research incorporated chitosan (CS) covalently crosslinked with glutaraldehyde (GLA) beads with graphene oxide (GO) nanosheets, titanium dioxide nanoparticles (TiO₂), and blackberry processing waste extract (BBE) and evaluated them as partial bone substitutes. Skullbone defects in biomodels filled with the scaffolds showed evidence through light microscopy, scanning electron microscopy, histological studies, soft tissue development with hair recovery, and absence of necrotic areas or aggressive infectious response of the immune system after 90 days of implantation. More interestingly, newly formed bone was evidenced by elemental analysis and Masson trichromacy analysis, which demonstrated a possible osteoinductive effect from the beads using the critical size defect experimental design in the biomodels. The results of this research are auspicious for the development of bone substitutes and evidence that the technologies for tissue regeneration, including chitosan nanocomposites, are beneficial for the adhesion and proliferation of bone cells. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Graphical abstract

19 pages, 2848 KiB

Open AccessArticle

Fe, N-Doped Metal Organic Framework Prepared by the Calcination of Iron Chelated Polyimines as the Cathode-Catalyst of Proton Exchange Membrane Fuel Cells

by Yu-Wei Cheng, Wen-Yao Huang, Ko-Shan Ho, Tar-Hwa Hsieh, Li-Cheng Jheng and Yang-Ming Kuo

Polymers 2021, 13(21), 3850; https://doi.org/10.3390/polym13213850 - 8 Nov 2021

Cited by 4 | Viewed by 2254

Abstract

Aromatic polyimine (PIM) was prepared through condensation polymerization between p-phenylene diamine and terephthalaldehyde via Schiff reactions. PIM can be physically crosslinked with ferrous ions into gel. The gel-composites, calcined at two consecutive stages, with temperatures ranging from 600 to 1000 °C, became Fe- [...] Read more.

Aromatic polyimine (PIM) was prepared through condensation polymerization between p-phenylene diamine and terephthalaldehyde via Schiff reactions. PIM can be physically crosslinked with ferrous ions into gel. The gel-composites, calcined at two consecutive stages, with temperatures ranging from 600 to 1000 °C, became Fe- and N-doped carbonaceous organic frameworks (FeNC), which demonstrated both graphene- and carbon nanotube-like morphologies and behaved as an electron-conducting medium. After the two-stage calcination, one at 1000 °C in N₂ and the other at 900 °C in a mixture of N₂ and NH₃, an FeNC composite (FeNC-1000A900) was obtained, which demonstrated a significant O₂ reduction peak in its current–voltage curve in the O₂ atmosphere, and thus, qualified as a catalyst for the oxygen reduction reaction. It also produced a higher reduction current than that of commercial Pt/C in a linear scanning voltage test, and the calculated e-transferred number reached 3.85. The max. power density reached 400 mW·cm⁻² for the single cell using FeNC-1000A900 as the cathode catalyst, which was superior to other FeNC catalysts that were calcined at lower temperatures. The FeNC demonstrated only 10% loss of the reduction current at 1600 rpm after 1000 redox cycles, as compared to be 25% loss for the commercial Pt/C catalyst in the durability test. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Graphical abstract

20 pages, 6927 KiB

Open AccessArticle

Effect of Strain Rate and Silica Filler Content on the Compressive Behavior of RTM6 Epoxy-Based Nanocomposites

by Ahmed Elmahdy, Aldobenedetto Zotti, Simona Zuppolini, Mauro Zarrelli, Anna Borriello and Patricia Verleysen

Polymers 2021, 13(21), 3735; https://doi.org/10.3390/polym13213735 - 28 Oct 2021

Cited by 10 | Viewed by 2313

Abstract

The aim of this paper is to investigate the effect of strain rate and filler content on the compressive behavior of the aeronautical grade RTM6 epoxy-based nanocomposites. Silica nanoparticles with different sizes, weight concentrations and surface functionalization were used as fillers. Dynamic mechanical [...] Read more.

The aim of this paper is to investigate the effect of strain rate and filler content on the compressive behavior of the aeronautical grade RTM6 epoxy-based nanocomposites. Silica nanoparticles with different sizes, weight concentrations and surface functionalization were used as fillers. Dynamic mechanical analysis was used to study the glass transition temperature and storage modulus of the nanocomposites. Using quasi-static and split Hopkinson bar tests, strain rates of 0.001 s⁻¹ to 1100 s⁻¹ were imposed. Sample deformation was measured using stereo digital image correlation techniques. Results showed a significant increase in the compressive strength with increasing strain rate. The elastic modulus and Poisson’s ratio showed strain rate independency. The addition of silica nanoparticles marginally increased the glass transition temperature of the resin, and improved its storage and elastic moduli and peak yield strength for all filler concentrations. Increasing the weight percentage of the filler slightly improved the peak yield strength. Moreover, the filler’s size and surface functionalization did not affect the resin’s compressive behavior at different strain rates. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Figure 1

11 pages, 40834 KiB

Open AccessArticle

Clinical Efficacy of Polycaprolactone β-Calcium Triphosphate Composite for Osteoconduction in Rabbit Bone Defect Model

by Chiu-Ming Chen, Shen-Mao Chen, Shiou-Fu Lin, Huang-Chien Liang and Chia-Chun Wu

Polymers 2021, 13(15), 2552; https://doi.org/10.3390/polym13152552 - 31 Jul 2021

Cited by 6 | Viewed by 2281

Abstract

The combination of β-tricalcium phosphate (β-TCP) with polycaprolactone (PCL) has been considered a promising strategy for designing scaffolds for bone grafting. This study incorporated PCL with commercially available β-TCP (Osteocera^TM) to fabricate an injectable bone substitute and evaluate the effect of [...] Read more.

The combination of β-tricalcium phosphate (β-TCP) with polycaprolactone (PCL) has been considered a promising strategy for designing scaffolds for bone grafting. This study incorporated PCL with commercially available β-TCP (Osteocera^TM) to fabricate an injectable bone substitute and evaluate the effect of PCL on compressive strength and setting time of the hydraulic cement. The mechanical testing was compliant with the ASTM D695 and ASTM C191-13 standards. Results showed that PCL-TCP composite presented a well-defined architecture with uniform pore distribution and a significant increase in compressive strength compared with β-TCP alone. Eighteen rabbits, each with two surgically created bone defects, were treated using the PCL-TCP composites. The composite materials were resorbed and replaced by newly formed bone tissue. Both PCL-TCP and β-TCP demonstrated equivalent clinical effects on osteoconduction property in terms of the percentage of newly formed bone area measured by histomorphometric analysis. PCL-TCP was proven to be as effective as the commercially available β-TCP scaffold (Osteocera^TM). Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Graphical abstract

19 pages, 3405 KiB

Open AccessArticle

Superparamagnetic, High Magnetic α-Fe & α″-Fe₁₆N₂ Mixture Prepared from Inverse Suspension-Polymerized Fe₃O₄@polyaniline Composite

by Yen-Zen Wang, Yu-Wei Cheng, Lin-Chia Ho, Wen-Yao Huang, Ko-Shan Ho and Yu-Ting Syu

Polymers 2021, 13(14), 2380; https://doi.org/10.3390/polym13142380 - 20 Jul 2021

Cited by 3 | Viewed by 2454

Abstract

Oleic acid (OA)-modified Fe₃O₄ nanoparticles were successfully covered with polyanilines (PANIs) via inverse suspension polymerization in accordance with SEM and TEM micrographs. The obtained nanoparticles were able to develop into a ferrite (α-Fe) and α″-Fe₁₆N₂ mixture with [...] Read more.

Oleic acid (OA)-modified Fe₃O₄ nanoparticles were successfully covered with polyanilines (PANIs) via inverse suspension polymerization in accordance with SEM and TEM micrographs. The obtained nanoparticles were able to develop into a ferrite (α-Fe) and α″-Fe₁₆N₂ mixture with a superparamagnetic property and high saturated magnetization (SM) of 245 emu g⁻¹ at 950 °C calcination under the protection of carbonization materials (calcined PANI) and other iron-compounds (α″-Fe₁₆N₂). The SM of the calcined iron-composites slightly decreases to 232 emu g⁻¹ after staying in the open air for 3 months. The calcined mixture composite can be ground into homogeneous powders without the segregation of the iron and carbon phases in the mortar without significantly losing magnetic activities. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Figure 1

11 pages, 9895 KiB

Open AccessArticle

Polyimide-Derived Carbon-Coated Li₄Ti₅O₁₂ as High-Rate Anode Materials for Lithium Ion Batteries

by Shih-Chieh Hsu, Tzu-Ten Huang, Yen-Ju Wu, Cheng-Zhang Lu, Huei Chu Weng, Jen-Hsien Huang, Cai-Wan Chang-Jian and Ting-Yu Liu

Polymers 2021, 13(11), 1672; https://doi.org/10.3390/polym13111672 - 21 May 2021

Cited by 10 | Viewed by 3200

Abstract

Carbon-coated Li₄Ti₅O₁₂ (LTO) has been prepared using polyimide (PI) as a carbon source via the thermal imidization of polyamic acid (PAA) followed by a carbonization process. In this study, the PI with different structures based on pyromellitic dianhydride [...] Read more.

Carbon-coated Li₄Ti₅O₁₂ (LTO) has been prepared using polyimide (PI) as a carbon source via the thermal imidization of polyamic acid (PAA) followed by a carbonization process. In this study, the PI with different structures based on pyromellitic dianhydride (PMDA), 4,4′-oxydianiline (ODA), and p-phenylenediamine (p-PDA) moieties have been synthesized. The effect of the PI structure on the electrochemical performance of the carbon-coated LTO has been investigated. The results indicate that the molecular arrangement of PI can be improved when the rigid p-PDA units are introduced into the PI backbone. The carbons derived from the p-PDA-based PI show a more regular graphite structure with fewer defects and higher conductivity. As a result, the carbon-coated LTO exhibits a better rate performance with a discharge capacity of 137.5 mAh/g at 20 C, which is almost 1.5 times larger than that of bare LTO (94.4 mAh/g). Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Figure 1

12 pages, 3455 KiB

Open AccessArticle

Synergistic and Regulatable Bioremediation Capsules Fabrication Based on Vapor-Phased Encapsulation of Bacillus Bacteria and its Regulator by Poly-p-Xylylene

by Yen-Ching Yang, Wei-Shen Huang, Shu-Man Hu, Chao-Wei Huang, Chih-Hao Chiu and Hsien-Yeh Chen

Polymers 2021, 13(1), 41; https://doi.org/10.3390/polym13010041 - 24 Dec 2020

Cited by 6 | Viewed by 2996

Abstract

A regulatable bioremediation capsule material was synthesized with isolated single-strain bacteria (Bacillus species, B. CMC1) and a regulator molecule (carboxymethyl cellulose, CMC) by a vapor-phased encapsulation method with simple steps of water sublimation and poly-p-xylylene deposition in chemical vapor [...] Read more.

A regulatable bioremediation capsule material was synthesized with isolated single-strain bacteria (Bacillus species, B. CMC1) and a regulator molecule (carboxymethyl cellulose, CMC) by a vapor-phased encapsulation method with simple steps of water sublimation and poly-p-xylylene deposition in chemical vapor deposition (CVD) process. Mechanically, the capsule construct exhibited a controllable shape and dimensions, and was composed of highly biocompatible poly-p-xylylene as the matrix with homogeneously distributed bacteria and CMC molecules. Versatility of the encapsulation of the molecules at the desired concentrations was achieved in the vapor-phased sublimation and deposition fabrication process. The discovery of the fabricated capsule revealed that viable living B. CMC1 inhabited the capsule, and the capsule enhanced bacterial growth due to the materials and process used. Biologically, the encapsulated B. CMC1 demonstrated viable and functional enzyme activity for cellulase activation, and such activity was regulatable and proportional to the concentration of the decorated CMC molecules in the same capsule construct. Impressively, 13% of cellulase activity increase was realized by encapsulation of B. CMC1 by poly-p-xylylene, and a further 34% of cellulase activity increase was achieved by encapsulation of additional 2.5% CMC. Accordingly, this synergistic effectiveness of the capsule constructs was established by combining enzymatic B. CMC1 bacteria and its regulatory CMC by poly-p-xylylene encapsulation process. This reported encapsulation process exhibited other advantages, including the use of simple steps and a dry and clean process free of harmful chemicals; most importantly, the process is scalable for mass production. The present study represents a novel method to fabricate bacteria-encapsulated capsule for cellulose degradation in bioremediation that can be used in various applications, such as wastewater treatment and transforming of cellulose into glucose for biofuel production. Moreover, the concept of this vapor-phased encapsulation technology can be correspondingly used to encapsulate multiple bacteria and regulators to enhance the specific enzyme functions for degradation of various organic matters. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Figure 1

15 pages, 3463 KiB

Open AccessEditor’s ChoiceArticle

Highly Thermal Stable Phenolic Resin Based on Double-Decker-Shaped POSS Nanocomposites for Supercapacitors

by Wei-Cheng Chen, Yuan-Tzu Liu and Shiao-Wei Kuo

Polymers 2020, 12(9), 2151; https://doi.org/10.3390/polym12092151 - 21 Sep 2020

Cited by 20 | Viewed by 3442

Abstract

In this study we incorporated various amounts of a double-decker silsesquioxane (DDSQ) into phenolic/DDSQ hybrids, which we prepared from a bifunctionalized phenolic DDSQ derivative (DDSQ-4OH), phenol, and CH₂O under basic conditions (with DDSQ-4OH itself prepared through hydrosilylation of nadic anhydride with [...] Read more.

In this study we incorporated various amounts of a double-decker silsesquioxane (DDSQ) into phenolic/DDSQ hybrids, which we prepared from a bifunctionalized phenolic DDSQ derivative (DDSQ-4OH), phenol, and CH₂O under basic conditions (with DDSQ-4OH itself prepared through hydrosilylation of nadic anhydride with DDSQ and subsequent reaction with 4-aminophenol). We characterized these phenolic/DDSQ hybrids using Fourier transform infrared spectroscopy; ¹H, ¹³C, and ²⁹Si nuclear magnetic resonance spectroscopy; X-ray photoelectron spectroscopy (XPS); and thermogravimetric analysis. The thermal decomposition temperature and char yield both increased significantly upon increasing the DDSQ content, with the DDSQ units providing an inorganic protection layer on the phenolic surface, as confirmed through XPS analyses. We obtained carbon/DDSQ hybrids from the phenolic/DDSQ hybrids after thermal curing and calcination at 900 °C; these carbon/DDSQ hybrids displayed electrochemical properties superior to those of previously reported counterparts. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Graphical abstract

11 pages, 2506 KiB

Open AccessArticle

A Novel Approach to Increase the Oxygen Permeability of Soft Contact Lenses by Incorporating Silica Sol

by Nguyen-Phuong-Dung Tran, Chuan-Cheng Ting, Chien-Hong Lin and Ming-Chien Yang

Polymers 2020, 12(9), 2087; https://doi.org/10.3390/polym12092087 - 14 Sep 2020

Cited by 19 | Viewed by 4415

Abstract

This study presents a novel approach to increase the oxygen permeability of hydrogel by the addition of silica sol. Herein, 2-hydroxyethyl methacrylate (HEMA) was copolymerized with N-vinyl-2-pyrrolidone (NVP) after mixing with silica sol. The resultant hydrogel was subject to characterizations including Fourier-transform infrared [...] Read more.

This study presents a novel approach to increase the oxygen permeability of hydrogel by the addition of silica sol. Herein, 2-hydroxyethyl methacrylate (HEMA) was copolymerized with N-vinyl-2-pyrrolidone (NVP) after mixing with silica sol. The resultant hydrogel was subject to characterizations including Fourier-transform infrared (FTIR), equilibrium water content (EWC), contact angle, optical transmittance, oxygen permeability (Dk), tensile test, anti-deposition of proteins, and cytotoxicity. The results showed that with the increase of silica content, the Dk values and Young’s moduli increased, the optical transmittance decreased slightly, whereas the EWC and contact angle, and protein deposition were not much affected. Moreover, the cytotoxicity of the resultant poly(HEMA-co-NVP)-SNPs indicated that the presence of silica sol was non-toxic and caused no effect to the growth of L929 cells. Thus, this approach increased the Dk of soft contact lenses without affecting their hydrophilicity. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Graphical abstract

13 pages, 4023 KiB

Open AccessArticle

Enhanced Thermal Conductivity of Silicone Composites Filled with Few-Layered Hexagonal Boron Nitride

by Wei-Cheng Cheng, Yi-Ting Hsieh and Wei-Ren Liu

Polymers 2020, 12(9), 2072; https://doi.org/10.3390/polym12092072 - 12 Sep 2020

Cited by 16 | Viewed by 4028

Abstract

In this study, we demonstrate the use of silicone/few-layered hexagonal boron nitride (FL-hBN) composites for heat dissipation applications. FL-hBN is synthesized via a green, facile, low-cost and scalable liquid exfoliation method using a jet cavitation process. The crystal structures, surface morphologies and specific [...] Read more.

In this study, we demonstrate the use of silicone/few-layered hexagonal boron nitride (FL-hBN) composites for heat dissipation applications. FL-hBN is synthesized via a green, facile, low-cost and scalable liquid exfoliation method using a jet cavitation process. The crystal structures, surface morphologies and specific surface areas of pristine h-BN and FL-hBN were characterized by XRD, SEM, TEM and AFM (atomic force microscopy). The results confirmed that FL-hBN with a thickness of ~4 nm was successfully obtained from the exfoliation process. In addition, we introduced both pristine h-BN and FL-hBN into silicone with different ratios to study their thermal properties. The results of the laser flash analysis indicate that the silicon/FL-hBN composite exhibited a higher thermal conductivity than that of the silicone/h-BN composite. With the optimal loading content of 30 wt.% FL-hBN content, the thermal conductivity of the composite could be enhanced to 230%, which is higher than that of silicone/h-BN (189%). These results indicate that jet cavitation is an effective and swift way to obtain few-layered hexagonal boron nitride that could effectively enhance the thermal conductivity of silicone composites. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Graphical abstract

Review

Jump to: Research

24 pages, 3204 KiB

Open AccessReview

Graphene/Polymer Nanocomposites: Preparation, Mechanical Properties, and Application

by Se Jung Lee, Seo Jeong Yoon and In-Yup Jeon

Polymers 2022, 14(21), 4733; https://doi.org/10.3390/polym14214733 - 4 Nov 2022

Cited by 41 | Viewed by 6810

Abstract

Although polymers are very important and vastly used materials, their physical properties are limited. Therefore, they are reinforced with fillers to relieve diverse restrictions and expand their application areas. The exceptional properties of graphene make it an interesting material with huge potential for [...] Read more.

Although polymers are very important and vastly used materials, their physical properties are limited. Therefore, they are reinforced with fillers to relieve diverse restrictions and expand their application areas. The exceptional properties of graphene make it an interesting material with huge potential for application in various industries and devices. The interfacial interaction between graphene and the polymer matrix improved the uniform graphene dispersion in the polymer matrix, enhancing the general nanocomposite performance. Therefore, graphene functionalization is essential to enhance the interfacial interaction, maintain excellent properties, and obstruct graphene agglomeration. Many studies have reported that graphene/polymer nanocomposites have exceptional properties that enable diverse applications. The use of graphene/polymer nanocomposites is expected to increase sustainably and to transform from a basic to an advanced material to offer optimum solutions to industry and consumers. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Figure 1

38 pages, 56389 KiB

Open AccessReview

Nanocomposite Polymer Electrolytes for Zinc and Magnesium Batteries: From Synthetic to Biopolymers

by María Fernanda Bósquez-Cáceres, Sandra Hidalgo-Bonilla, Vivian Morera Córdova, Rose M. Michell and Juan P. Tafur

Polymers 2021, 13(24), 4284; https://doi.org/10.3390/polym13244284 - 7 Dec 2021

Cited by 8 | Viewed by 4831

Abstract

The diversification of current forms of energy storage and the reduction of fossil fuel consumption are issues of high importance for reducing environmental pollution. Zinc and magnesium are multivalent ions suitable for the development of environmentally friendly rechargeable batteries. Nanocomposite polymer electrolytes (NCPEs) [...] Read more.

The diversification of current forms of energy storage and the reduction of fossil fuel consumption are issues of high importance for reducing environmental pollution. Zinc and magnesium are multivalent ions suitable for the development of environmentally friendly rechargeable batteries. Nanocomposite polymer electrolytes (NCPEs) are currently being researched as part of electrochemical devices because of the advantages of dispersed fillers. This article aims to review and compile the trends of different types of the latest NCPEs. It briefly summarizes the desirable properties the electrolytes should possess to be considered for later uses. The first section is devoted to NCPEs composed of poly(vinylidene Fluoride-co-Hexafluoropropylene). The second section centers its attention on discussing the electrolytes composed of poly(ethylene oxide). The third section reviews the studies of NCPEs based on different synthetic polymers. The fourth section discusses the results of electrolytes based on biopolymers. The addition of nanofillers improves both the mechanical performance and the ionic conductivity; key points to be explored in the production of batteries. These results set an essential path for upcoming studies in the field. These attempts need to be further developed to get practical applications for industry in large-scale polymer-based electrolyte batteries. Full article

(This article belongs to the Special Issue Advanced Polymer Nanocomposites II)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Advanced Polymer Nanocomposites II

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (23 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI