Polymers

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18 pages, 4987 KiB

Open AccessArticle

The Low Velocity Impact Response of Shape Memory Alloy Hybrid Polymer Composites

by Hao Li, Jingbiao Liu, Zhenqing Wang, Zhengwei Yu, Yanfei Liu and Min Sun

Polymers 2018, 10(9), 1026; https://doi.org/10.3390/polym10091026 - 14 Sep 2018

Cited by 14 | Viewed by 4713

Abstract

Polymer composites are sensitive to impact loading due to their low impact resistance. Shape memory alloy (SMA) wires have been used to improve the impact resistance of the polymer composite materials because of their unique superelasticity performance. In this study, a new SMA [...] Read more.

Polymer composites are sensitive to impact loading due to their low impact resistance. Shape memory alloy (SMA) wires have been used to improve the impact resistance of the polymer composite materials because of their unique superelasticity performance. In this study, a new SMA hybrid basalt fiber-reinforced polymer composite embedded with two perpendicular layers of superelastic SMA wires is designed and the low-velocity impact behavior is experimental investigated. For contrast, the conventional polymer composite without SMA wires is also tested as the reference laminate. The tests are carried out at three different impact energy levels (30, 60 and 90 J). Moreover, to find out indications for manufacturing of SMA hybrid composites with high impact resistance, four different SMA wires embedded modes are investigated. Visual inspection and scanning electron microscope methods are adopted to identify the damage modes of the impacted samples. Results show that the impact resistance of the hybrid laminates is improved due to the hybridization of SMA wires. The most effective impact resistance of the SMA hybrid composites can be obtained by incorporating the SMA wires with one layer between the front two plies and another layer between the bottom two plies into the composite structure. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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14 pages, 7190 KiB

Open AccessArticle

Fabrication of PPy Nanosphere/rGO Composites via a Facile Self-Assembly Strategy for Durable Microwave Absorption

by Ying Wang, Yunchen Du, Bo Wu, Binhua Han, Shaoming Dong, Xijiang Han and Ping Xu

Polymers 2018, 10(9), 998; https://doi.org/10.3390/polym10090998 - 6 Sep 2018

Cited by 28 | Viewed by 4910

Abstract

Traditional magnetic metal and alloy materials suffer from easy oxidation and high density, which hinders their practical application as high-performance microwave absorbers. Lightweight and durability have become new goals in the fabrication of the next generation of microwave absorbers. Herein, we report the [...] Read more.

Traditional magnetic metal and alloy materials suffer from easy oxidation and high density, which hinders their practical application as high-performance microwave absorbers. Lightweight and durability have become new goals in the fabrication of the next generation of microwave absorbers. Herein, we report the synthesis of polypyrrole (PPy) nanosphere/reduced graphene oxide (rGO) composites through chemical reduction of self-assembly PPy nanosphere/GO hybrids. PPy nanospheres and GO are integrated effectively by π–π interaction of dual conjugated systems. When the mass ratio of PPy nanospheres to rGO is 0.6:1, the resultant composite, PPy/rGO-0.6, presents comparable/superior reflection loss characteristics to those magnetic metals and their related graphene-based composites in previous studies. Electromagnetic analysis reveals that well-matched characteristic impedance, multiple polarization loss, and good conductivity loss are, together, responsible for the excellent microwave absorption performance of PPy/rGO-0.6. More importantly, PPy/rGO-0.6 also exhibits good microwave absorption after being treated at 423 K for a long time. This work provides a new idea for designing and preparing a high-performance microwave absorber with lightweight and durable features. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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11 pages, 3981 KiB

Open AccessCommunication

Fixing PAN Nanofiber Mats during Stabilization for Carbonization and Creating Novel Metal/Carbon Composites

by Lilia Sabantina, Miguel Ángel Rodríguez-Cano, Michaela Klöcker, Francisco José García-Mateos, Juan José Ternero-Hidalgo, Al Mamun, Friederike Beermann, Mona Schwakenberg, Anna-Lena Voigt, José Rodríguez-Mirasol, Tomás Cordero and Andrea Ehrmann

Polymers 2018, 10(7), 735; https://doi.org/10.3390/polym10070735 - 4 Jul 2018

Cited by 47 | Viewed by 6300

Abstract

Polyacrylonitrile (PAN) is one of the materials most often used for carbonization. PAN nanofiber mats, created by electrospinning, are an especially interesting source to gain carbon nanofibers. A well-known problem in this process is fixing the PAN nanofiber mats during the stabilization process [...] Read more.

Polyacrylonitrile (PAN) is one of the materials most often used for carbonization. PAN nanofiber mats, created by electrospinning, are an especially interesting source to gain carbon nanofibers. A well-known problem in this process is fixing the PAN nanofiber mats during the stabilization process which is necessary to avoid contraction of the fibers, correlated with an undesired increase in the diameter and undesired bending. Fixing this issue typically results in breaks in the nanofiber mats if the tension is too high, or it is not strong enough to keep the fibers as straight as in the original state. This article suggests a novel method to overcome this problem by electrospinning on an aluminum substrate on which the nanofiber mat adheres rigidly, stabilizing the composite and carbonizing afterwards either with or without the aluminum substrate to gain either a pure carbon nanofiber mat or a metal/carbon composite. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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12 pages, 2070 KiB

Open AccessArticle

Construction of a Different Polymer Chain Structure to Study π-π Interaction between Polymer and Reduced Graphene Oxide

by Dan Zhao, Guangda Zhu, Yong Ding and Junping Zheng

Polymers 2018, 10(7), 716; https://doi.org/10.3390/polym10070716 - 29 Jun 2018

Cited by 31 | Viewed by 4832

Abstract

In this work, a different polymer chain structure was synthesized to study π-π interactions between polymer and reduced graphene oxide (RGO). Polymers with different chain structures were obtained from free radical copolymerization of styrene with 4-cyanostyrene (containing substituted phenyl rings) and 2-vinylnaphthalene (containing [...] Read more.

In this work, a different polymer chain structure was synthesized to study π-π interactions between polymer and reduced graphene oxide (RGO). Polymers with different chain structures were obtained from free radical copolymerization of styrene with 4-cyanostyrene (containing substituted phenyl rings) and 2-vinylnaphthalene (containing naphthalene rings). In this work, the polystyrene, poly(styrene-co-4-cyanostyrene) and poly(styrene-co-2-vinylnaphthalene) were named as PS, PSCN and PSNP, respectively. RGO was prepared through modified Hummers’ method and further thermal reduction, and nanocomposites were prepared by solution blending. Thus, different π-π interactions were formed between polymers and RGO. Raman and thermal gravimetric analysis (TGA) were used to characterize the interfacial interaction, showing that the trend of the interfacial interaction should be in the order of RGO/PSCN, RGO/PS, and RGO/PSNP. The differential scanning calorimetry (DSC) measurement showed that, compared with polymer matrix, the glass transition temperature (T_g) of RGO/PS, RGO/PSCN and RGO/PSNP nanocomposites with the addition of 4.0 wt% RGO are increased by 14.3 °C, 25.2 °C and 4.4 °C, respectively. Compared with π-π interaction only formed through aromatic rings, substituent groups changed the densities of electron clouds on the phenyl rings. This change resulted in the formation of donor-acceptor interaction and reinforcement of the π-π interaction at the interface, which leads to increased value of T_g. This comparative study can be useful for selecting appropriate interaction groups, as well as suitable monomers, to prepare high performance nanocomposites. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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13 pages, 4032 KiB

Open AccessArticle

Effect of a Surfactant in Microcapsule Synthesis on Self-Healing Behavior of Capsule Embedded Polymeric Films

by Jiyeon Lee, Seon Joo Park, Chul-Soon Park, Oh Seok Kwon, So Young Chung, Jongwon Shim, Chang-Soo Lee and Joonwon Bae

Polymers 2018, 10(6), 675; https://doi.org/10.3390/polym10060675 - 17 Jun 2018

Cited by 14 | Viewed by 5747

Abstract

Recently, there has been increased interest in self-healing membranes containing functional microcapsules in relation to challenges involving water treatment membranes. In this study, a self-healing membrane has been prepared by incorporating microcapsules with a polyurethane (PU) shell and a diisocyanate core in a [...] Read more.

Recently, there has been increased interest in self-healing membranes containing functional microcapsules in relation to challenges involving water treatment membranes. In this study, a self-healing membrane has been prepared by incorporating microcapsules with a polyurethane (PU) shell and a diisocyanate core in a poly(ether sulfone) (PES) membrane. Depending on the characteristics of the microcapsule, to precisely quantify the self-healing behavior and performance of the produced microcapsule embedded membranes, it is important to understand the effect of a used surfactant on microcapsule synthesis. It is noteworthy that mixed surfactants have been employed to control and tailor the size and morphology of microcapsules during the synthetic process, and the surfactant system employed was one of the most dominant parameters for affecting the healing capability of microcapsule embedded membranes. Various techniques including microscopy (optical and electron), thermal analyses (DSC and TGA), and water flux measurements have been employed. This article provides essential and important information for future research into the subtle relation between microcapsule properties with varied synthetic parameters and the self-healing behavior of membrane. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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12 pages, 1857 KiB

Open AccessArticle

Green Modification of Corn Stalk Lignin and Preparation of Environmentally Friendly Lignin-Based Wood Adhesive

by Sen Wang, Yalan Yu and Mingwei Di

Polymers 2018, 10(6), 631; https://doi.org/10.3390/polym10060631 - 7 Jun 2018

Cited by 45 | Viewed by 5367

Abstract

In this study, corn stalk lignin was used to react with non-volatile and non-toxic glyoxal under the catalysis of a sodium hydroxide solution, and a wood adhesive based on glyoxalated corn stalk lignin was prepared. The effect of the hydroxylation reaction on the [...] Read more.

In this study, corn stalk lignin was used to react with non-volatile and non-toxic glyoxal under the catalysis of a sodium hydroxide solution, and a wood adhesive based on glyoxalated corn stalk lignin was prepared. The effect of the hydroxylation reaction on the structure and properties of lignin were studied using Fourier transform infrared spectroscopy (FTIR), ultraviolet spectrophotometry (UV), thermogravimetric analysis (TGA), titration tests, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). Compared with unmodified lignin, the glyoxalated corn stalk lignin had a significant improvement in hydroxyl content, activation, and thermal stability. At the same time, results from the GPC showed that the molecular weight increased compared with original corn stalk, possibly due to the secondary polycondensation reaction between lignin and glyoxal. Lignin-based environmental wood adhesives were prepared by mixing modified lignin and epichlorohydrin (ECH), and the dry strength of plywood reached 1.58 MPa. The mechanical strength and water resistance of plywood was improved significantly by mixing some aqueous emulsion into lignin-based adhesives, e.g., polyacrylic ester (AE) emulsion and aqueous polyurethane (PU) emulsion. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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8 pages, 2605 KiB

Open AccessArticle

Electrospun PVA Polymer Embedded with Ceria Nanoparticles as Silicon Solar Cells Rear Surface Coaters for Efficiency Improvement

by Effat Samir, Mohamed Salah, Ali Hajjiah, Nader Shehata, Marwa Fathy and Aya Hamed

Polymers 2018, 10(6), 609; https://doi.org/10.3390/polym10060609 - 4 Jun 2018

Cited by 8 | Viewed by 3726

Abstract

This paper introduces electrospun nanofibers embedded with ceria nanoparticles as silicon solar cells coaters, showing their influence on the solar cells efficiency. Ceria nanoparticles can be synthesized to have formed oxygen vacancies (O-vacancies), which are associated with converting cerium ions from the Ce [...] Read more.

This paper introduces electrospun nanofibers embedded with ceria nanoparticles as silicon solar cells coaters, showing their influence on the solar cells efficiency. Ceria nanoparticles can be synthesized to have formed oxygen vacancies (O-vacancies), which are associated with converting cerium ions from the Ce⁴⁺ state ions to the Ce³⁺ ones. These O-vacancies follow the rule of improving silicon solar cellconductivity through the hopping mechanism. Besides, under violet excitation, the reduced trivalent cerium Ce³⁺ ions are directly responsible for down-converting the un-absorbed violet or ultra-violet (UV) wavelengths to a resulted green fluorescence emission at ~520 nm. These are absorbed through the silicon solar cells active layer. When electrospun Poly(vinyl alcohol) (PVA) is embedded with ceria nanoparticles on the rear surface of silicon solar cell, a promising enhancement in the behavior of solar cells current–voltage (I–V) curve is observed. The efficiency has improved by about 24% of its initial value due to the mutual impact of improving both electrical conductivity and optical conversions from the higher surface-to-volume ratio of electrospun nanofibers embedded by ceria nanoparticles. The solar cell efficiency improvement is due to the mutual impact of both optical down-conversion and better electric paths via the used nanocomposite. The added nanostructures coating can utilize part of the transmitted UV or violet spectrum through the cell as optical conversion from violet to the visible region. In addition, the formed active tri-valent states are associated with O-vacancies which can help in a better conductivity of the generated photoelectrons from the cell through the hopping mechanism. The PVA nanofibers host offers a better distribution of ceria nanoparticles and better conductivity paths for the photoelectrons based on the better surface-to-volume ratio of the nanofibers. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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15 pages, 6161 KiB

Open AccessArticle

Hybrid Materials Based on Poly-3-amine-7-methylamine-2-methylphenazine and Magnetite Nanoparticles Immobilized on Single-Walled Carbon Nanotubes

by Sveta Zhiraslanovna Ozkan, Galina Petrovna Karpacheva, Petr Aleksandrovich Chernavskii, Ella Leont’evna Dzidziguri, Galina Nikolaevna Bondarenko and Galina Viktorovna Pankina

Polymers 2018, 10(5), 544; https://doi.org/10.3390/polym10050544 - 18 May 2018

Cited by 7 | Viewed by 4008

Abstract

Polymer-metal-carbon hybrid nanomaterials based on thermostable electroactive poly-3-amine-7-methylamine-2-methylphenazine (PAMMP), single walled carbon nanotubes (SWCNT), and magnetite (Fe₃O₄) nanoparticles were synthesized for the first time. Hybrid Fe₃O₄/SWCNT/PAMMP nanomaterial synthesis was carried out via in situ chemical [...] Read more.

Polymer-metal-carbon hybrid nanomaterials based on thermostable electroactive poly-3-amine-7-methylamine-2-methylphenazine (PAMMP), single walled carbon nanotubes (SWCNT), and magnetite (Fe₃O₄) nanoparticles were synthesized for the first time. Hybrid Fe₃O₄/SWCNT/PAMMP nanomaterial synthesis was carried out via in situ chemical oxidative polymerization of 3-amine-7-methylamine-2-methylphenazine hydrochloride in the presence of metal-carbon Fe₃O₄/SWCNT nanocomposites. Fe₃O₄/SWCNT nanocomposites were obtained by the immobilization of magnetite nanoparticles on the SWCNT surface in the course of Fe₃O₄ nanoparticles synthesis in alkaline medium. The developed nanocomposite materials were characterized by FTIR spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission (FE-SEM) scanning electron microscopy, atomic absorption spectrometry (AAS), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and magnetometry. The chemical structure and phase composition, magnetic and electrical properties, and thermal stability of the obtained multifunctional nanomaterials, depending on synthesis conditions, were investigated. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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15 pages, 8215 KiB

Open AccessArticle

Antibacterial Capability, Physicochemical Properties, and Biocompatibility of nTiO₂ Incorporated Polymeric Scaffolds

by Cijun Shuai, Chenying Shuai, Pei Feng, Chengde Gao, Shuping Peng and Youwen Yang

Polymers 2018, 10(3), 328; https://doi.org/10.3390/polym10030328 - 16 Mar 2018

Cited by 35 | Viewed by 5001

Abstract

Postoperative infection is a common risk which brings about failure in bone transplantation. In this study, nano titanium dioxide (nTiO₂) was incorporated into Polyetheretherketone/polyglycolicacid (PEEK/PGA) blends to construct antibacterial scaffolds via selective laser sintering. Antibacterial capability was assessed using Escherichia coli [...] Read more.

Postoperative infection is a common risk which brings about failure in bone transplantation. In this study, nano titanium dioxide (nTiO₂) was incorporated into Polyetheretherketone/polyglycolicacid (PEEK/PGA) blends to construct antibacterial scaffolds via selective laser sintering. Antibacterial capability was assessed using Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The results demonstrated that the scaffolds with nTiO₂ presented an effective antibacterial activity, which might be attributed to that nTiO₂ would do the mechanical and oxidative damage to bacteria by occurring contact actions and generating reactive oxygen species (ROS), and thus killed bacteria from structure and function. Moreover, nTiO₂ could enhance the tensile strength and modulus of scaffolds due to the reinforcing effect and its uniform disperse. And the cell culture experiments showed that nTiO₂ stimulated cellular attachment and proliferation. Besides, it also elevated the hydrophily and thermal stability of scaffolds. These results suggested that the polymeric scaffolds incorporated nTiO₂ had potential application in bone tissue engineering. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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17 pages, 6543 KiB

Open AccessArticle

Engineering Polyzwitterion and Polydopamine Decorated Doxorubicin-Loaded Mesoporous Silica Nanoparticles as a pH-Sensitive Drug Delivery

by Feng Ji, Hong Sun, Zhihui Qin, Ershuai Zhang, Jing Cui, Jinmei Wang, Shuofeng Li and Fanglian Yao

Polymers 2018, 10(3), 326; https://doi.org/10.3390/polym10030326 - 15 Mar 2018

Cited by 30 | Viewed by 8144

Abstract

Multifunctional drug carriers have great applications in biomedical field. In this study, we introduced both polydopamine (PDA) and zwitterionic polymer of poly(3-(3-methacrylamidopropyl-(dimethyl)-ammonio)propane-1-sulfonate) (PSPP) onto the surface of mesoporous silica nanoparticles (MSNs) to develop a novel nanoparticle (MSNs@PDA-PSPP), which was employed as a new [...] Read more.

Multifunctional drug carriers have great applications in biomedical field. In this study, we introduced both polydopamine (PDA) and zwitterionic polymer of poly(3-(3-methacrylamidopropyl-(dimethyl)-ammonio)propane-1-sulfonate) (PSPP) onto the surface of mesoporous silica nanoparticles (MSNs) to develop a novel nanoparticle (MSNs@PDA-PSPP), which was employed as a new kind of drug carrier for the delivery of doxorubicin (DOX). The PDA coating, as a gatekeeper, could endow the drug carrier with pH-sensitive drug release performance. The outermost PSPP layer would make the drug carrier possess protein resistance performance. The chemical structure and properties were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS) and thermogravimetric analysis (TGA). MSNs@PDA-PSPP could keep good colloidal stability within 72 h in phosphate buffered saline (PBS) and protein solutions. Meanwhile, MSNs@PDA-PSPP exhibited a high drug loading for DOX. In vitro drug release experiments suggested MSNs-DOX@PDA-PSPP exhibited pH-dependent drug release behaviors. Besides, MSNs@PDA-PSPP had no cytotoxicity to human hepatocellular carcinoma cells (HepG2 cells) even at a concentration of 125 µg/mL. More importantly, cellular uptake and in vitro anticancer activity tests suggested that MSNs-DOX@PDA-PSPP could be taken up by HepG2 cells and DOX could be successfully released and delivered into the cell nuclei. Taken together, MSNs@PDA-PSPP have great potential in the biomedical field. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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13 pages, 3103 KiB

Open AccessArticle

A Novel Application of Phosphorene as a Flame Retardant

by Xinlin Ren, Yi Mei, Peichao Lian, Delong Xie, Yunyan Yang, Yongzhao Wang and Zirui Wang

Polymers 2018, 10(3), 227; https://doi.org/10.3390/polym10030227 - 26 Feb 2018

Cited by 49 | Viewed by 6565

Abstract

Black phosphorene-waterborne polyurethane (BPWPU) composite polymer with 0.2 wt % of black phosphorene was synthesized. Scanning electron microscopy (SEM) was used to observe the morphology of phosphorene in polyurethane matrix, which indicated that the phosphorene distributes uniformly in the PU matrix. The flammability [...] Read more.

Black phosphorene-waterborne polyurethane (BPWPU) composite polymer with 0.2 wt % of black phosphorene was synthesized. Scanning electron microscopy (SEM) was used to observe the morphology of phosphorene in polyurethane matrix, which indicated that the phosphorene distributes uniformly in the PU matrix. The flammability measurements were carried out to investigate the flame-resistant performances of phosphorene, which indicated that phosphorene could effectively restrict the degradation of the PU membrane. Compared by the pure WPU, the limiting oxygen index (LOI) of BPWPU increased by 2.6%, the heat flow determined by thermal analysis significantly decreased by 34.7% moreover, the peak heat release rate (PHRR) decreased by 10.3%. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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14 pages, 2493 KiB

Open AccessArticle

Polycomplexes of Hyaluronic Acid and Borates in a Solid State and Solution: Synthesis, Characterization and Perspectives of Application in Boron Neutron Capture Therapy

by Alexander N. Zelenetskii, Sergey Uspenskii, Alexander Zaboronok, Georgij Cherkaev, Alexander Shchegolihin, Bryan J. Mathis, Mikhail Selyanin, Tetsuya Yamamoto and Akira Matsumura

Polymers 2018, 10(2), 181; https://doi.org/10.3390/polym10020181 - 13 Feb 2018

Cited by 14 | Viewed by 5954

Abstract

In this report, we propose a new polyborate fragment synthesis strategy along the whole chain of the polysaccharide hyaluronic acid (HA) to produce boron neutron capture therapy (BNCT) compounds. Under high pressure and deformatory solid-state conditions, polymolecular system formation takes place due to [...] Read more.

In this report, we propose a new polyborate fragment synthesis strategy along the whole chain of the polysaccharide hyaluronic acid (HA) to produce boron neutron capture therapy (BNCT) compounds. Under high pressure and deformatory solid-state conditions, polymolecular system formation takes place due to association of phase-specific transition components into a more or less distinct microscopic organization. Fourier transform infrared (FTIR) spectroscopy shows that HA and polyborates form a network of cyclic polychelate complexes. HA acts as a multidentate ligand using carboxylic and hydroxyl proton donor groups to link oxygen atoms in B–O–B bonds and borate-anions B–O(−): O–H···O, O–H···(−)O. With free electron pairs in heteroatoms –O(:)···B, –N(:)···B, HA can act simultaneously as an electron donor. Nuclear magnetic resonance (NMR) with ¹³C and ¹H reveals a preserved complex interaction after both solubilizing and attenuating the HA-polyborate system. Stability of the product in water, low cost, ease of synthesis and scalability of manufacturing indicate that HA-polyborate complexes might have advantages over current chemotherapeutic approaches in creating therapeutic agents for BNCT. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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13 pages, 2712 KiB

Open AccessArticle

Sortase-Mediated Ligation of Purely Artificial Building Blocks

by Xiaolin Dai, Diana M. Mate, Ulrich Glebe, Tayebeh Mirzaei Garakani, Andrea Körner, Ulrich Schwaneberg and Alexander Böker

Polymers 2018, 10(2), 151; https://doi.org/10.3390/polym10020151 - 6 Feb 2018

Cited by 12 | Viewed by 6329

Abstract

Sortase A (SrtA) from Staphylococcus aureus has been often used for ligating a protein with other natural or synthetic compounds in recent years. Here we show that SrtA-mediated ligation (SML) is universally applicable for the linkage of two purely artificial building blocks. Silica [...] Read more.

Sortase A (SrtA) from Staphylococcus aureus has been often used for ligating a protein with other natural or synthetic compounds in recent years. Here we show that SrtA-mediated ligation (SML) is universally applicable for the linkage of two purely artificial building blocks. Silica nanoparticles (NPs), poly(ethylene glycol) and poly(N-isopropyl acrylamide) are chosen as synthetic building blocks. As a proof of concept, NP–polymer, NP–NP, and polymer–polymer structures are formed by SrtA catalysis. Therefore, the building blocks are equipped with the recognition sequence needed for SrtA reaction—the conserved peptide LPETG—and a pentaglycine motif. The successful formation of the reaction products is shown by means of transmission electron microscopy (TEM), matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-ToF MS), and dynamic light scattering (DLS). The sortase catalyzed linkage of artificial building blocks sets the stage for the development of a new approach to link synthetic structures in cases where their synthesis by established chemical methods is complicated. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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Review

Jump to: Research

21 pages, 2488 KiB

Open AccessReview

Recent Overviews in Functional Polymer Composites for Biomedical Applications

by Moustafa M. Zagho, Essraa A. Hussein and Ahmed A. Elzatahry

Polymers 2018, 10(7), 739; https://doi.org/10.3390/polym10070739 - 4 Jul 2018

Cited by 139 | Viewed by 10610

Abstract

Composite materials are considered as an essential part of our daily life due to their outstanding properties and diverse applications. Polymer composites are a widespread class of composites, characterized by low cost, facile processing methods, and varied applications ranging from daily-use issues to [...] Read more.

Composite materials are considered as an essential part of our daily life due to their outstanding properties and diverse applications. Polymer composites are a widespread class of composites, characterized by low cost, facile processing methods, and varied applications ranging from daily-use issues to highly complicated electronics and advanced medical combinations. In this review, we focus on the most important fabrication techniques for bioapplied polymer composites such as electrospinning, melt-extrusion, solution mixing, and latex technology, as well as in situ methods. Additionally, significant and recent advances in biomedical applications are spotlighted, such as tissue engineering (including bone, blood vessels, oral tissues, and skin), dental resin-based composites, and wound dressing. Full article

(This article belongs to the Special Issue Polymer Hybrid Materials)

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