Fabrication of moth eye-like patterned polystyrene films and their functionalization with polyaniline <i>via</i> interfacial reaction

Modigunta, Jeevan Kumar Reddy,Kim, Jun Mo,Song, Hanjung,Huh, Do Sung Butterworth Scientific Ltd. etc. 2019 Polymer Vol.179 No.-

<P><B>Abstract</B></P> <P>Moth eye-like patterned (MEP) polystyrene (PS) films with a hexagonal array of microdomes mimicking natural moth eye were fabricated by pouring a PS solution on a honeycomb-patterned porous polyvinyl alcohol film using as a template. The surface of microdomes on the PS MEP film containing benzoyl peroxide (BPO) was functionalized with polyaniline (PANI) through interfacial reaction by using aniline hydrochloride to enhance their functionality of the MEP patterned film. The PANI functionalization on the MEP film was confirmed by UV–visible spectroscopy, scanning electron microscopy and EDX analysis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Moth eye-like PS films are fabricated using honeycomb-patterned film as a template. </LI> <LI> The patterned films were functionalized with polyaniline by interfacial reaction. </LI> <LI> The functionalization of PANI was identified by SEM and conductivity of the film. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Enhancing the durability of filtration the ultrafine aerosol by electrospun polymer filter containing quaternary ammonium moiety

Lee, Su-Bin,Cho, Hee-Joo,Ha, Yu-Mi,Kim, Seo-Jeong,Chung, Byung-Joo,Son, Won Keun,Kang, Kyung Seok,Jung, Yong Chae,Park, Kihong,Lee, Jae-Suk Butterworth Scientific Ltd. etc. 2017 Polymer Vol. No.

<P><B>Abstract</B></P> <P>Functionalized polymer filter (FPF) was fabricated using a synthesized terpolymer containing a quaternary ammonium moiety via electrospinning method to enhance the durability of air filters. Removal efficiency and durability of FPF were exhibited compared with those of polystyrene (PS) filter and a commercial electret filter. FPF showed the best performance than others, and the removal efficiencies were 89.5, 98.6, and 99.8% when the sodium chloride aerosol were sized in 100, 200, and 300 nm, respectively. In addition, FPF had almost no decrease in the removal efficiency after the treatment by isopropyl alcohol (IPA). On the other hand, the IPA-treated PS and electret filter showed the rapid decrease around 20–40% for the sodium chloride aerosol. The performance of FPF was also kept even after the water treatment. Furthermore, FPF also showed good antibacterial activity, a desirable characteristic for using the air filter without infections.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Functionalized polymer filter was fabricated for removal of ultrafine aerosol. </LI> <LI> Hydrophilicity and high dipole moment from the quaternary ammonium moiety were helpful to capture the MPPS. </LI> <LI> Durability of the filter was improved owing to the inherent characteristics of the functionalized terpolymer. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Conductive poly(high internal phase emulsion) foams incorporated with polydopamine-coated carbon nanotubes

Kim, Haseung,Ahn, Kyung Hyun,Lee, Seong Jae Butterworth Scientific Ltd. etc. 2017 Polymer Vol. No.

<P><B>Abstract</B></P> <P>Electrically conductive poly(high internal phase emulsion) (polyHIPE) nanocomposite foams based on poly(styrene-co-divinylbenzene) were prepared by incorporating polydopamine-coated carbon nanotubes (PDA-CNTs). Conductive yet amphiphobic CNTs were modified to PDA-CNTs by coating with PDA on the surface of CNTs to provide hydrophilicity. As a result, it was possible to prepare highly stable HIPEs having PDA-CNT content >10 wt% and resultant polyHIPE foams having enhanced conductivity due to the good dispersion of PDA-CNTs in aqueous phase. The foams made with a water-to-monomer ratio of 10:1 showed well-developed interconnected microcellular structure. With increasing PDA-CNT content, the yield stress and storage modulus of HIPE increased and the cell size of the polyHIPE foam decreased. The electrical percolation threshold was determined to be less than PDA-CNT 1 wt% and the conductivity at PDA-CNT content of 8 wt% was increased to as high as 10<SUP>−2</SUP> Sm<SUP>−1</SUP>. Surface modification of CNTs by PDA was very effective in providing electrical conductivity due to their stable dispersion in aqueous phase while keeping the intrinsic properties of CNTs intact.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Electrically conductive poly(high internal phase emulsion) foams are prepared. </LI> <LI> Polydopamine-coated carbon nanotubes are effective in providing conductivity. </LI> <LI> Highly stable HIPEs are made possible by excellent dispersion of the CNTs. </LI> <LI> The cell size of poly(HIPE) foams decreases with increasing the CNT content. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Design and synthesis of polyaniline-grafted reduced graphene oxide via azobenzene pendants for high-performance supercapacitors

Male, Umashankar,Modigunta, Jeevan Kumar Reddy,Huh, Do Sung Butterworth Scientific Ltd. etc. 2017 Polymer Vol. No.

<P><B>Abstract</B></P> <P>To increase the pseudo-capacitance and cycle stability of polyaniline (PANI), PANI was covalently attached to reduced graphene oxide (rGO) via azobenzene (Azo) units. The rGO-Azo composite was first synthesized and subsequently used for the in situ chemical polymerization of aniline to form PANI-rGO-Azo composites. The Azo units on rGO functioned as spacers to prevent the agglomeration of rGO and increase the solubility of rGO to assist in the in situ polymerization of aniline to form PANI-rGO-Azo composite. The Azo units act as linkers for the covalent attachment of PANI chains to graphene, thereby enhance the overall performance of the composite materials. The electrochemical properties of the composites were evaluated by fabricating symmetric two-electrode cell configuration and also compared with three electrode system. The charge transfer resistance of PANI is reduced from 6.6 Ω to 2.9 Ω, by grafting PANI onto rGO-Azo. The specific capacitance of PANI-rGO-Azo (328 F g<SUP>-1</SUP>) is higher than that of PANI (270 F g<SUP>-1</SUP>) and rGO-Azo (114 F g<SUP>-1</SUP>). The electrochemical performance of PANI was enhanced by grafting of PANI onto rGO-Azo.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Charger transfer resistance of PANI is reduced by grafting onto rGO-Azo. </LI> <LI> Knee frequency of PANI-rGO-Azo was higher than PANI. </LI> <LI> 80% of initial capacitance was retained even after 1500 charge-discharge cycles. </LI> <LI> PANI-rGO-Azo shows higher electrochemical performances than PANI. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Coupling of breath figure method with interfacial polymerization: Bottom-surface functionalized honeycomb-patterned porous films

Male, Umashankar,Shin, Bo Kyoung,Huh, Do Sung Butterworth Scientific Ltd. etc. 2017 Polymer Vol. No.

<P><B>Abstract</B></P> <P>A new and facile method was designed for the fabrication of asymmetrically polyaniline (PANI) functionalized polystyrene (PS) honeycomb-patterned porous films in a single step. The method involves the coupling of breath figure process with an interfacial polymerization, wherein the PS solution containing benzoyl peroxide in an organic solvent was cast under humid conditions over an aqueous solvent containing aniline and methane sulfonic acid. PANI was coated on the bottom surface at the organic/aqueous interface by an interfacial polymerization method, whereas a porous patterned PS was fabricated on the top surface by the breath figure method. The films revealed a translucent insulating PS top surface and a conducting green PANI bottom surface. The obtained films represented asymmetrical composition, color, morphology, conductivity, and contact angle on either surface.</P> <P><B>Highlights</B></P> <P> <UL> <LI> First report on asymmetric functionalized honeycomb patterned films. </LI> <LI> Film was obtained by coupling interfacial polymerization with breath figure process. </LI> <LI> It has asymmetrical color, composition, morphology, contact angle and conductivity. </LI> <LI> These can be used in applications where asymmetrical property is a requirement. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Benzotriazole-based donor-acceptor type low band gap polymers with a siloxane-terminated side-chain for electrochromic applications

Suganya, S.,Kim, N.,Jeong, J.Y.,Park, J.S. Butterworth Scientific Ltd. etc. 2017 Polymer Vol. No.

A series of donor-acceptor (D-A) type polymers (P1-P4) bearing a benzotriazole group with a siloxane terminated side-chain and a long alkyl chain were synthesized via Stille coupling, and the electrochromic (EC) properties were characterized by various analytical techniques. The incorporation of hybrid siloxane-solubilizing groups in P1 and P2 influenced the intermolecular interactions among the adjacent polymer chains and increased the solubility of the resulting polymers in common organic solvents. The EC behavior of the polymers revealed a color transition from red to blue upon oxidation and reduction. In particular, P1, containing a short siloxane-terminated side-chain, showed superior optical performances, with transmittance change of 42.7%, the change in optical density of 0.767, and coloration efficiency of up to 327 cm<SUP>2</SUP>/C, and exhibited superior operational stability, with little transmittance changes after 100 potential steps. Overall, these properties highlight the potential applications of current polymers in displays and smart windows.

In <i>vitro</i> biocompatibility of vapour phase polymerised conductive scaffolds for cell lines

Choi, Jong Seob,Park, Jin Seul,Kim, Boram,Lee, Byong-Taek,Yim, Jin-Heong Butterworth Scientific Ltd. etc. 2017 Polymer Vol. No.

<P><B>Abstract</B></P> <P>Conductive polymers have been intensively studied for their potential applications in cell therapy, neural regeneration, and drug delivery. They can also be used as scaffolds for tissue engineering. Ideal scaffolds are porous, interconnected structures that allow cell entry and can thus mimic in <I>vivo</I> three-dimensional (3D) tissue regeneration. In the present study, poly(3,4-ethylenedioxythiophene)-silica and polypyrrole-silica composites were fabricated by a two-step procedure for use as 3D conductive porous scaffolds. A hybrid conductive composite layer was first formed by vapour phase polymerisation on a 3D microparticle assembly. Microparticles were then selectively removed, yielding a highly porous skeletal structure. The in <I>vitro</I> biocompatibility of the scaffolds was investigated by culturing with HepG2 and MC3T3-E1 cells, and evaluating cell viability with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and examining cell morphology by scanning electron and confocal microscopy. We found that the two scaffolds effectively promoted cell proliferation, indicating that conductive polymer-based scaffolds can be useful for investigating the behaviour of muscle and nerve cells under electrical stimulation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PEDOT-SiO<SUB>2</SUB> and PPy-SiO<SUB>2</SUB> based 3D conductive porous scaffolds were prepared by VPP. </LI> <LI> In <I>vitro</I> biocompatibility of the scaffolds was confirmed by culturing with two kinds of cells. </LI> <LI> The scaffolds can be useful for studying the behaviour of cells under electrical stimulation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>In this paper, we investigated the biocompatible study of 3D conductive scaffolds mechanically and electrically enhanced by simultaneous co-vaporized VPP.</P> <P>[DISPLAY OMISSION]</P>

Preparation of pendant group-functionalized amphiphilic diblock copolymers in the presence of a monomer activator and evaluation as temperature-responsive hydrogels

Lee, Hye Yun,Park, Ji Hoon,Ji, Yun Bae,Kwon, Doo Yeon,Lee, Bo Keun,Kim, Jae Ho,Park, Kinam,Kim, Moon Suk Butterworth Scientific Ltd. etc. 2018 Polymer Vol. No.

<P><B>Abstract</B></P> <P>Temperature-responsive hydrogels have been widely developed for biomedical applications. In this study, 4-benzyloxy-ε-caprolactone (CL-OBn) was synthesized and the subsequent ring opening polymerization (ROP) of ε-caprolactone (CL) and CL-OBn monomers was performed by using the hydroxyl group of methoxy polyethylene glycol (MPEG) in the presence of HCl·Et<SUB>2</SUB>O as a monomer activator. MPEG-<I>b</I>-poly (ε-caprolactone) (MC) with benzyl pendant groups (MC-OBn) was successfully obtained in almost quantitative yield and the segment ratios and molecular weights were close to the theoretical values. Deprotection of the benzyl pendant groups successfully provided MC with hydroxyl pendant groups (MC-OH). Suspensions of MC-OBn and MC-OH exhibited distinct sol-to-gel phase transitions as a function of the temperature. The sol-to-gel phase transition of the MC-OBn and MC-OH diblock copolymers depended on the type (benzyl or hydroxyl) and amount of pendant groups in the diblock copolymer structure. The pendant group on the MC-OBn and MC-OH diblock copolymers either stabilized and/or destabilized hydrophobic aggregation between the MC segments. The hydrophobic aggregation was confirmed by the detection of crystallinity in the MC-OBn and MC-OH diblock copolymer suspensions. In conclusion, MC-OBn and MC-OH diblock copolymers were successfully prepared and served as temperature-responsive hydrogels.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The ROP of CL and CL-OBn by the metal-free method successfully provided. </LI> <LI> The MC-OH diblock copolymers were also obtained by a deprotection reaction. </LI> <LI> MC-OBn and MC-OH acted as temperature-responsive hydrogels. </LI> <LI> The pendant groups weakened and/or prohibited hydrophobic aggregation. </LI> <LI> The temperature-responsive hydrogels can be utilized for biomedical applications. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Continuous thermal-rolling of electrospun nanofiber for polyamide layer deposition and its detection by engineered osmosis

Son, Moon,Bae, Jiyeol,Park, Hosik,Choi, Heechul Butterworth Scientific Ltd. etc. 2018 Polymer Vol. No.

<P><B>Abstract</B></P> <P>In this study, electrospun nanofiber was continuously sandwiched between two rubber rollers at high temperature (150 °C). The prepared nanofiber support layer possessed a pore size of 0.4 μm (with narrow distribution) and a fiber diameter of 292 ± 94 nm. Afterward, an interfacial polymerization was employed to deposit the selective polyamide layer on the nanofiber support layer. For the first time, engineered osmosis (EO) was used as a platform for verifying the presence of a polyamide selective layer on a nanofiber support layer. We found that the membrane prepared exhibited an excellent combination of permeability (30 L/m<SUP>2</SUP>h) and selectivity (17 g/m<SUP>2</SUP>h and 0.57 g/L) under a net pressure of 49 bar at the EO platform. The membrane developed can be applied to generate renewable energy using the EO process. In addition, the EO method can be used to detect selective polymer having a nano-scale thickness.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The polyamide layer was successfully synthesized on nanofiber. </LI> <LI> The continuous thermal-rolling was applied as a pretreatment. </LI> <LI> An osmosis-based platform was employed to detect polyamide. </LI> <LI> The TNC exhibited excellent permselectivity. </LI> <LI> This method is easy to upscale. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Solution-processable methyl-substituted semi-alicyclic homo- and co-polyimides and their gas permeation properties

Shin, So-Ra,Moon, Su-Young,Park, Chae-Young,Chang, Bong-Jun,Kim, Jeong-Hoon Butterworth Scientific Ltd. etc. 2018 Polymer Vol. No.

<P><B>Abstract</B></P> <P>Because of their excellent thermal, chemical and physical properties, as well as high gas selectivity, polyimides are promising polymers for gas separation membranes. However, their commercial use is limited due to their relatively poor solubility and permeability. Here, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-cyclohexane-1,2-dicarboxylic anhydride (DOCDA) was used to improve the solubility of the polyimides, and various methyl-substituted diamines were introduced to increase their permeability, due to the effect of the bulky methyl groups. Polyimides based on DOCDA (DOCDA-PIs), synthesized via one-step solution polymerization, exhibited high solubility in common organic solvents and improved gas permeability due to the non-planar structure of DOCDA and the presence of methyl groups, which disturbed chain packing, an effect that was correlated with increased fractional free volume (FFV) and d-spacing. Co-polyimides based on DOCDA, DOCDA-coPIs, exhibited high gas permeability and CO<SUB>2</SUB>/CH<SUB>4</SUB> and O<SUB>2</SUB>/N<SUB>2</SUB> selectivity, comparable to commercial polymeric membranes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Alicyclic polyimides containing different methyl substituent groups were synthesized by the one-step imidization. </LI> <LI> lDOCDA-PIs showed excellent solubility in organic solvents thanks to the incorporation of asymmetric alicyclic groups. </LI> <LI> The methyl substituents had a crucial effect on gas permeability. </LI> <LI> The DOCDA-coPIs had permeability and selectivity values similar to commercial polymeric membranes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>