Functional and Conductive Polymer Thin Films II

A special issue of Polymers (ISSN 2073-4360). This special issue belongs to the section "Polymer Analysis and Characterization".

Deadline for manuscript submissions: closed (20 November 2020) | Viewed by 30835

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Department of Chemical and Materials Engineering, National Yun-Lin University of Science and Technology, Yun-Lin 64002, Taiwan
Interests: nanocomposite; biomedical materials; separation technology
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Dear Colleagues,

The development of materials is a key factor for industry growth and innovation, with Enhanced material functionalities effectively promoting the profundity and breadth of original material applications. Material functionality methods include chemical modifications and compounding from physical blending, while functional polymers represent polymers bearing functional groups that have a greater polarity or reactivity than simple linear backbones. Polymer functionalization aims at offering new properties to materials. These include separation membranes for fuel cells, electrodes in batteries, organic catalysis, medicine, optoelectronics, biomaterials, photographic materials, fuel additives, etc. Conductive polymers are organic polymers that conduct electricity. The electrical properties can be modulated using the methods of organic synthesis and via excellent dispersion techniques. It is worth mentioning that the total number of papers on conducting polymers to date (2020) according to scientific databases is more than 300,000, and the literature suggests that they are promising in catalysts, photovoltaic cells, batteries, organic solar cells, batteries, transistor, wearable smart devices, organic light-emitting diodes, actuators, electrochromic devices, supercapacitors, electrochemical biosensors and bioelectronics, flexible transparent displays, electromagnetic shielding and microwave-absorbent coatings, and others. A thin film is a layer of material ranging from the nanometer scale to several micrometers in thickness. Since layers are thin relative to length scale, interface effects are much more important than in bulk materials, bringing about novel physical properties. The film properties and functions have become a major research field. The synthesis of polymer as thin films is a key step in numerous applications (e.g., protective, smart coatings to electronics, sensors and display technology, as well as serving biological and medical purposes).

The core subject matter of the Special Issue is to discern the fundamental and advancement aspects for the synthesis, fabrication, characterization, properties, and foresights of functional and conductive polymer thin films, as well as their copolymers, composites, and nanocomposites.

Prof. Yen-Zen Wang
Guest Editor

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Keywords

  • synthesis and fabrication of functional and conductive polymer thin films
  • synthesis and application of flexible and transparent conducting polymer thin films
  • polymers for green energy cells
  • polymers for electrodes in electronic and optoelectronic devices
  • polymers for supercapacitors
  • polymers for wearable electronics
  • polymers for electrochemical sensors
  • polymers for electrochromic devices

Published Papers (9 papers)

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Research

16 pages, 4507 KiB  
Article
Thermoresponsive and Conductive Chitosan-Polyurethane Biocompatible Thin Films with Potential Coating Application
by Junpeng Xu, Chih-Yu Fu, Yu-Liang Tsai, Chui-Wei Wong and Shan-hui Hsu
Polymers 2021, 13(3), 326; https://doi.org/10.3390/polym13030326 - 20 Jan 2021
Cited by 13 | Viewed by 2992
Abstract
Conductive thin films have great potential for application in the biomedical field. Herein, we designed thermoresponsive and conductive thin films with hydrophilicity, strain sensing, and biocompatibility. The crosslinked dense thin films were synthesized and prepared through a Schiff base reaction and ionic interaction [...] Read more.
Conductive thin films have great potential for application in the biomedical field. Herein, we designed thermoresponsive and conductive thin films with hydrophilicity, strain sensing, and biocompatibility. The crosslinked dense thin films were synthesized and prepared through a Schiff base reaction and ionic interaction from dialdehyde polyurethane, N-carboxyethyl chitosan, and double-bonded chitosan grafted polypyrrole. The thin films were air-dried under room temperature. These thin films showed hydrophilicity and conductivity (above 2.50 mS/cm) as well as responsiveness to the deformation. The tensile break strength (9.72 MPa to 15.07 MPa) and tensile elongation (5.76% to 12.77%) of conductive thin films were enhanced by heating them from 25 °C to 50 °C. In addition, neural stem cells cultured on the conductive thin films showed cell clustering, proliferation, and differentiation. The application of the materials as a conductive surface coating was verified by different coating strategies. The conductive thin films are potential candidates for surface modification and biocompatible polymer coating. Full article
(This article belongs to the Special Issue Functional and Conductive Polymer Thin Films II)
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19 pages, 4604 KiB  
Article
Relationship between Photoelasticity of Polyurethane and Dielectric Anisotropy of Diisocyanate, and Application of High-Photoelasticity Polyurethane to Tactile Sensor for Robot Hands
by Masahiko Mitsuzuka, Yuho Kinbara, Mizuki Fukuhara, Maki Nakahara, Takashi Nakano, Jun Takarada, Zhongkui Wang, Yoshiki Mori, Masakazu Kageoka, Tsutomu Tawa, Sadao Kawamura and Yoshiro Tajitsu
Polymers 2021, 13(1), 143; https://doi.org/10.3390/polym13010143 - 31 Dec 2020
Cited by 13 | Viewed by 4591
Abstract
Eight types of polyurethane were synthesized using seven types of diisocyanate. It was found that the elasto-optical constant depends on the concentration of diisocyanate groups in a unit volume of a polymer and the magnitude of anisotropy of the dielectric constant of diisocyanate [...] Read more.
Eight types of polyurethane were synthesized using seven types of diisocyanate. It was found that the elasto-optical constant depends on the concentration of diisocyanate groups in a unit volume of a polymer and the magnitude of anisotropy of the dielectric constant of diisocyanate groups. It was also found that incident light scattered when bending stress was generated inside photoelastic polyurethanes. A high sensitive tactile sensor for robot hands was devised using one of the developed polyurethanes with high photoelasticity. Full article
(This article belongs to the Special Issue Functional and Conductive Polymer Thin Films II)
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15 pages, 3181 KiB  
Article
Calcined Co(II)-Triethylenetetramine, Co(II)- Polyaniline-Thiourea as the Cathode Catalyst of Proton Exchanged Membrane Fuel Cell
by Wen-Yao Huang, Li-Cheng Jheng, Tar-Hwa Hsieh, Ko-Shan Ho, Yen-Zen Wang, Yi-Jhun Gao and Po-Hao Tseng
Polymers 2020, 12(12), 3070; https://doi.org/10.3390/polym12123070 - 21 Dec 2020
Cited by 7 | Viewed by 2563
Abstract
Triethylenetetramine (TETA) and thiourea complexed Cobalt(II) (Co(II)) ions are used as cathode catalysts for proton exchanged membrane fuel cells (PEMFCs) under the protection of polyaniline (PANI) which can become a conducting medium after calcination. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) [...] Read more.
Triethylenetetramine (TETA) and thiourea complexed Cobalt(II) (Co(II)) ions are used as cathode catalysts for proton exchanged membrane fuel cells (PEMFCs) under the protection of polyaniline (PANI) which can become a conducting medium after calcination. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectra clearly reveal the presence of typical carbon nitride and sulfide bonds of the calcined Nitrogen (N)- or Sulfur (S)-doped co-catalysts. Clear (002) and (100) planes of carbon-related X-ray diffraction patterns are found for co-catalysts after calcination, related to the formation of a conducting medium after the calcination of PANI. An increasing intensity ratio of the D to G band of the Raman spectra reveal the doping of N and S elements. More porous surfaces of co-catalysts are found in scanning electronic microscopy (SEM) micropictures when prepared in the presence of both TETA and thiourea (CoNxSyC). Linear sweep voltammetry (LSV) curves show the highest reducing current to be 4 mAcm−2 at 1600 rpm for CoNxSyC, indicating the necessity for both N- and S-doping. The membrane electrode assemblies (MEA) prepared with the cathode made of CoNxSyC produces the highest maximum power density, close to 180 mW cm−2. Full article
(This article belongs to the Special Issue Functional and Conductive Polymer Thin Films II)
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13 pages, 3480 KiB  
Article
Conductive Polyaniline Doped with Dodecyl Benzene Sulfonic Acid: Synthesis, Characterization, and Antistatic Application
by Cheng-Ho Chen, Jing-Mei Wang and Wei-Yu Chen
Polymers 2020, 12(12), 2970; https://doi.org/10.3390/polym12122970 - 12 Dec 2020
Cited by 9 | Viewed by 2639
Abstract
A novel method was conducted to synthesize conductive polyaniline (PANI) doped with dodecyl benzene sulfonic acid (DBSA) (PANDB) in xylene by using chemical oxidative polymerization at 25 °C. Meanwhile, the synthesis process was photographed. Results showed as the reaction time was increased, and [...] Read more.
A novel method was conducted to synthesize conductive polyaniline (PANI) doped with dodecyl benzene sulfonic acid (DBSA) (PANDB) in xylene by using chemical oxidative polymerization at 25 °C. Meanwhile, the synthesis process was photographed. Results showed as the reaction time was increased, and the color of the product was gradually turned into dark green. The influence of different synthesis time on properties of synthesized PANDB was then examined by a Fourier transform infrared (FTIR) spectrometer, an ultraviolet-visible spectrophotometer (UV-vis), a four-point measurement method, and a Field-emittance scanning electron microscope (FE-SEM). The result indicated that the optimum reaction time was 24 h with conductivity at around 2.03 S/cm. FE-SEM images and the conductivity testing showed that the more needle-like shapes in resulted PANDB, the higher the conductivity. The synthesized PANDB solution was blended with UV curable coating firstly and then coated on polyethylene terephthalate (PET) sheet. The UV coating/PANDB conductive composite films displayed an impressive translucency along with an adequate flexibility at room temperature. The UV coating/PANDB conductive composite film on PET sheet was flexible, transparent, and with antistatic function. Full article
(This article belongs to the Special Issue Functional and Conductive Polymer Thin Films II)
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9 pages, 3742 KiB  
Article
Numerical Modeling of Ink Widening and Coating Gap in Roll-to-Roll Slot-Die Coating of Solid Oxide Fuel Cell Electrolytic Layer
by Seongyong Kim, Jongsu Lee, Minho Jo and Changwoo Lee
Polymers 2020, 12(12), 2927; https://doi.org/10.3390/polym12122927 - 07 Dec 2020
Cited by 5 | Viewed by 3501
Abstract
Slot-die coatings are advantageous when used for coating large-area flexible devices; in particular, the coating width can be controlled and simultaneous multi-layer coatings can be processed. To date, the effects of ink widening and the coating gap on the coating thickness have only [...] Read more.
Slot-die coatings are advantageous when used for coating large-area flexible devices; in particular, the coating width can be controlled and simultaneous multi-layer coatings can be processed. To date, the effects of ink widening and the coating gap on the coating thickness have only been considered in a few studies. To this end, we developed two mathematical models to accurately estimate the coating width and thickness that consider these two effects. We used root mean square deviation (RMSD) to experimentally verify the developed method. When the coating gap was increased, the coating width increased and the coating thickness decreased. Experimental results showed that the estimated performances of the coating width and thickness models were as high as 98.46% and 95.8%, respectively. We think that the developed models can be useful for determining the coating conditions according to the ink properties to coat a functional layer with user-defined widths and thicknesses in both lab- and industrial-scale roll-to-roll slot-die coating processes. Full article
(This article belongs to the Special Issue Functional and Conductive Polymer Thin Films II)
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16 pages, 19405 KiB  
Article
Bifunctional Microcapsules with n-Octadecane/Thyme Oil Core and Polyurea Shell for High-Efficiency Thermal Energy Storage and Antibiosis
by Xianfeng Wang, Chunhong Li, Meihui Wang, Tao Zhao and Wenyao Li
Polymers 2020, 12(10), 2226; https://doi.org/10.3390/polym12102226 - 28 Sep 2020
Cited by 15 | Viewed by 2915
Abstract
A new kind of bifunctional microcapsule containing a n-octadecane (OD) and thyme oil (TO) core based on polyurea shell designed for thermal energy storage and antibiosis was prepared successfully through interfacial polymerization. The scanning electron microscopic investigations reveal that the obtained composite microcapsules [...] Read more.
A new kind of bifunctional microcapsule containing a n-octadecane (OD) and thyme oil (TO) core based on polyurea shell designed for thermal energy storage and antibiosis was prepared successfully through interfacial polymerization. The scanning electron microscopic investigations reveal that the obtained composite microcapsules present the regular spherical morphology and the transmission electron microscopic observations confirm the clear core–shell structure. Morphological and chemical structure analyses prove the successful synthesis of bifunctional microcapsules. Thermogravimetric analysis indicates that the polyurea shell can protect the composite cores effectively. Differential scanning calorimetry examination shows that the bifunctional microcapsules can maintain high thermal storage capacity and the encapsulation efficiency of OD increases with the increase in TO. The supercooling crystallization can be notably suppressed by adding 7 wt.% of n-octadecanol. A study on the release behavior of TO from the bifunctional microcapsules reveals that the Higuchi kinetic model could better fit the TO release profile. The antibacterial results demonstrate that the bifunctional microcapsules can effectively inhibit the growth of Staphylococcus aureus and the inhibition rate can reach as high as 99.9% when the mass concentration of microcapsules is over 3 wt.%. Full article
(This article belongs to the Special Issue Functional and Conductive Polymer Thin Films II)
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18 pages, 4316 KiB  
Article
Blending and Characteristics of Electrochemical Double-Layer Capacitor Device Assembled from Plasticized Proton Ion Conducting Chitosan:Dextran:NH4PF6 Polymer Electrolytes
by Shujahadeen B. Aziz, Mohamad A. Brza, Iver Brevik, Muhamad H. Hafiz, Ahmad S.F.M. Asnawi, Yuhanees M. Yusof, Rebar T. Abdulwahid and Mohd F.Z. Kadir
Polymers 2020, 12(9), 2103; https://doi.org/10.3390/polym12092103 - 16 Sep 2020
Cited by 30 | Viewed by 2731
Abstract
This research paper investigates the electrochemical performance of chitosan (CS): dextran (DX) polymer-blend electrolytes (PBEs), which have been developed successfully with the incorporation of ammonium hexafluorophosphate (NH4PF6). X-ray diffraction (XRD) analysis indicates that the plasticized electrolyte system with the [...] Read more.
This research paper investigates the electrochemical performance of chitosan (CS): dextran (DX) polymer-blend electrolytes (PBEs), which have been developed successfully with the incorporation of ammonium hexafluorophosphate (NH4PF6). X-ray diffraction (XRD) analysis indicates that the plasticized electrolyte system with the highest value of direct current (DC) ionic conductivity is the most amorphous system. The glycerol addition increased the amorphous phase and improved the ionic dissociation, which contributed to the enhancement of the fabricated device’s performance. Transference number analysis (TNM) has shown that the charge transport process is mainly by ions rather than electrons, as tion = 0.957. The CS:DX:NH4PF6 system was found to decompose as the voltage goes beyond 1.5 V. Linear sweep voltammetry (LSV) revealed that the potential window for the most plasticized system is 1.5 V. The fabricated electrochemical double-layer capacitor (EDLC) was analyzed with cyclic voltammetry (CV) and charge-discharge analysis. The results from CV verify that the EDLC in this work holds the characteristics of a capacitor. The imperative parameters of the fabricated EDLC such as specific capacitance and internal resistance were found to be 102.9 F/g and 30 Ω, respectively. The energy stored and power delivered by the EDLC were 11.6 Wh/kg and 2741.2 W/kg, respectively. Full article
(This article belongs to the Special Issue Functional and Conductive Polymer Thin Films II)
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21 pages, 3555 KiB  
Article
Drawbacks of Low Lattice Energy Ammonium Salts for Ion-Conducting Polymer Electrolyte Preparation: Structural, Morphological and Electrical Characteristics of CS:PEO:NH4BF4-Based Polymer Blend Electrolytes
by Mohamad A. Brza, Shujahadeen B. Aziz, Muaffaq M. Nofal, Salah R. Saeed, Shakhawan Al-Zangana, Wrya O. Karim, Sarkawt A. Hussen, Rebar T. Abdulwahid and Mohd F. Z. Kadir
Polymers 2020, 12(9), 1885; https://doi.org/10.3390/polym12091885 - 21 Aug 2020
Cited by 24 | Viewed by 3123
Abstract
In the present work it was shown that low lattice energy ammonium salts are not favorable for polymer electrolyte preparation for electrochemical device applications. Polymer blend electrolytes based on chitosan:poly(ethylene oxide) (CS:PEO) incorporated with various amounts of low lattice energy NH4BF [...] Read more.
In the present work it was shown that low lattice energy ammonium salts are not favorable for polymer electrolyte preparation for electrochemical device applications. Polymer blend electrolytes based on chitosan:poly(ethylene oxide) (CS:PEO) incorporated with various amounts of low lattice energy NH4BF4ammonium salt have been prepared using the solution cast technique. Both structural and morphological studies were carried out to understand the phenomenon of ion association. Sharp peaks appeared in X-ray diffraction (XRD) spectra of the samples with high salt concentration. The degree of crystallinity increased from 8.52 to 65.84 as the salt concentration increased up to 40 wt.%. These are correlated to the leakage of the associated anions and cations of the salt to the surface of the polymer. The structural behaviors were further confirmed by morphological study. The morphological results revealed the large-sized protruded salts at high salt concentration. Based on lattice energy of salts, the phenomena of salt leakage were interpreted. Ammonium salts with lattice energy lower than 600 kJ/mol are not preferred for polymer electrolyte preparation due to the significant tendency of ion association among cations and anions. Electrical impedance spectroscopy was used to estimate the conductivity of the samples. It was found that the bulk resistance increased from 1.1 × 104 ohm to 0.7 × 105 ohm when the salt concentration raised from 20 wt.% to 40 wt.%, respectively; due to the association of cations and anions. The low value of direct current (DC) conductivity (7.93 × 10−7 S/cm) addressed the non-suitability of the electrolytes for electrochemical device applications. The calculated values of the capacitance over the interfaces of electrodes-electrolytes (C2) were found to drop from 1.32 × 10−6 F to 3.13 × 10−7 F with increasing salt concentration. The large values of dielectric constant at low frequencies are correlated to the electrode polarization phenomena while their decrements with rising frequency are attributed to the lag of ion polarization in respect of the fast orientation of the applied alternating current (AC) field. The imaginary part of the electric modulus shows obvious peaks known as conduction relaxation peaks. Full article
(This article belongs to the Special Issue Functional and Conductive Polymer Thin Films II)
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14 pages, 3277 KiB  
Article
High-Molecular-Weight PLA-b-PEO-b-PLA Triblock Copolymer Templated Large Mesoporous Carbons for Supercapacitors and CO2 Capture
by Mohamed Gamal Mohamed, Wei-Shih Hung, Ahmed F. M. EL-Mahdy, Mahmoud M. M. Ahmed, Lizong Dai, Tao Chen and Shiao-Wei Kuo
Polymers 2020, 12(5), 1193; https://doi.org/10.3390/polym12051193 - 23 May 2020
Cited by 20 | Viewed by 4782
Abstract
High-molecular-weight PLA440-b-PEO454-b-PLA440 (LEL) triblock copolymer was synthesized through simple ring-opening polymerization (ROP) by using the commercial homopolymer HO-PEO454-OH as the macro-initiator. The material acted as a single template to prepare the large [...] Read more.
High-molecular-weight PLA440-b-PEO454-b-PLA440 (LEL) triblock copolymer was synthesized through simple ring-opening polymerization (ROP) by using the commercial homopolymer HO-PEO454-OH as the macro-initiator. The material acted as a single template to prepare the large mesoporous carbons by using resol-type phenolic resin as a carbon source. Self-assembled structures of phenolic/LEL blends mediated by hydrogen bonding interaction were determined by FTIR and SAXS analyses. Through thermal curing and carbonization procedures, large mesoporous carbons (>50 nm) with a cylindrical structure and high surface area (>600 m2/g) were obtained because the OH units of phenolics prefer to interact with PEO block rather than PLA block, as determined by FTIR spectroscopy. Furthermore, higher CO2 capture and good energy storage performance were observed for this large mesoporous carbon, confirming that the proposed approach provides an easy method for the preparation of large mesoporous materials. Full article
(This article belongs to the Special Issue Functional and Conductive Polymer Thin Films II)
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