Polymers

Research

Jump to: Review

13 pages, 3074 KiB

Open AccessArticle

Fluorine-Free Hydrophobic Modification and Waterproof Breathable Properties of Electrospun Polyacrylonitrile Nanofibrous Membranes

by Ling Zhang, Junlu Sheng, Yongbo Yao, Zhiyong Yan, Yunyun Zhai, Zhongfeng Tang and Haidong Li

Polymers 2022, 14(23), 5295; https://doi.org/10.3390/polym14235295 - 3 Dec 2022

Cited by 8 | Viewed by 2235

Abstract

Waterproof breathable functional membranes have broad application prospects in the field of outdoors textiles. The fluorine-containing microporous membranes of the mainstream functional products easily cause harm to the environment, and thus, the fluorine-free environmental nanofibrous membranes are an important development direction for functional [...] Read more.

Waterproof breathable functional membranes have broad application prospects in the field of outdoors textiles. The fluorine-containing microporous membranes of the mainstream functional products easily cause harm to the environment, and thus, the fluorine-free environmental nanofibrous membranes are an important development direction for functional membranes. In this subject, the electrospun polyacrylonitrile nanofibrous membranes were first hydrophobically modified by amino functional modified polysiloxane (AMP), followed by in situ cross-linking modified with 4, 4’-methyl diphenylene diisocyanate (MDI). The fluorine-free modification by AMP altered the surface of the membranes from hydrophilic to hydrophobic, and greatly improved the waterproof properties with the hydrostatic pressure reaching to 87.6 kPa. In addition, the formation of bonding points and the in situ preparation of polyuria through the reaction between the isocyanate in MDI and the amino group in AMP, could improve the mechanical properties effectively. When using AMP with the concentration of 1 wt% and MDI with the concentration of 2 wt%, the relatively good comprehensive performance was obtained with good water resistance (93.8 kPa), modest vapor permeability (4.7 kg m⁻² d⁻¹) and air permeability (12.7 mm/s). Based on these testing data, the modified nanofibrous membranes had excellent waterproof and breathable properties, which has future potential in outdoor sports apparel. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Graphical abstract

10 pages, 1650 KiB

Open AccessArticle

Binary Polyamide-Imide Fibrous Superelastic Aerogels for Fire-Retardant and High-Temperature Air Filtration

by Yuezhen Hua, Wang Cui, Zekai Ji, Xin Wang, Zheng Wu, Yong Liu and Yuyao Li

Polymers 2022, 14(22), 4933; https://doi.org/10.3390/polym14224933 - 15 Nov 2022

Cited by 1 | Viewed by 1639

Abstract

Fibrous air filtration materials are highly desirable for particle removal from high-temperature emission sources. However, the existing commercial filter materials suffer from either low filtration efficiency or high pressure drop, due to the difficulty in achieving small fiber diameter and high porosity simultaneously. [...] Read more.

Fibrous air filtration materials are highly desirable for particle removal from high-temperature emission sources. However, the existing commercial filter materials suffer from either low filtration efficiency or high pressure drop, due to the difficulty in achieving small fiber diameter and high porosity simultaneously. Herein, we report a facile strategy to fabricate mechanical robust fibrous aerogels by using dual-scale sized PAI/BMI filaments and fibers, which are derived from wet spinning and electrospinning technologies, respectively. The creativity of this design is that PAI/BMI filaments can serve as the enhancing skeleton and PAI/BMI fibers can assemble into high-porosity interconnected networks, enabling the improvement of both mechanical property and air filtration performance. The resultant dual-scale sized PAI/PBMI fibrous aerogels show a compressive stress of 8.36 MPa, a high filtration efficiency of 90.78% (particle diameter of 2.5 μm); for particle diameter over 5 μm, they have 99.99% ultra-high filtration efficiency, a low pressure drop of 20 Pa, and high QF of 0.12 Pa⁻¹, as well as thermostable and fire-retardant properties (thermal decomposition temperature up to 342.7 °C). The successive fabrication of this material is of great significance for the govern of industrial dust. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

14 pages, 4434 KiB

Open AccessArticle

Numerical Analysis of Fiber/Air-Coupling Field for Annular Jet

by Yudong Wang, Hongzhi Wei, Yumei Chen, Meixiang Liao, Xiuping Wu, Mingcai Zhong, Yang Luo, Bin Xue, Changchun Ji and Yuhong Tian

Polymers 2022, 14(21), 4630; https://doi.org/10.3390/polym14214630 - 31 Oct 2022

Cited by 2 | Viewed by 1337

Abstract

Melt-blowing technology is an important method for directly preparing micro-nanofiber materials by drawing polymer melts with high temperature and high velocity air flow. During the drawing process, the melt-blowing fiber not only undergoes a phase change, but also has an extremely complex coupling [...] Read more.

Melt-blowing technology is an important method for directly preparing micro-nanofiber materials by drawing polymer melts with high temperature and high velocity air flow. During the drawing process, the melt-blowing fiber not only undergoes a phase change, but also has an extremely complex coupling effect with the drawing airflow. Therefore, in the numerical calculation of the flow field, the existence of melt-blowing fibers is often ignored. In this paper, based on the volume of fluid method, a numerical study of the flexible fiber/air-coupling flow field of an annular melt-blowing die is carried out with the aid of computational fluid dynamics software. The results show that the pressure distribution in the different central symmetry planes of the ring die at the same time was basically the same. However, the velocity distribution may have been different; the velocity on the spinning line varied with time; the pressure changes on the spinning line were small; and velocity fluctuations around the spinning line could cause whiplash of the fibers. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

17 pages, 14302 KiB

Open AccessArticle

Carboxylated Carbon Nanotube/Polyimide Films with Low Thermal Expansion Coefficient and Excellent Mechanical Properties

by Cheng Lu, Fangbing Lin, Huiqi Shao, Siyi Bi, Nanliang Chen, Guangwei Shao and Jinhua Jiang

Polymers 2022, 14(21), 4565; https://doi.org/10.3390/polym14214565 - 27 Oct 2022

Cited by 8 | Viewed by 2044

Abstract

Polyimide (PI) films with excellent heat resistance and outstanding mechanical properties have been widely researched in microelectronics and aerospace fields. However, most PI films can only be used under ordinary conditions due to their instability of dimension. The fabrication of multifunctional PI films [...] Read more.

Polyimide (PI) films with excellent heat resistance and outstanding mechanical properties have been widely researched in microelectronics and aerospace fields. However, most PI films can only be used under ordinary conditions due to their instability of dimension. The fabrication of multifunctional PI films for harsh conditions is still a challenge. Herein, flexible, low coefficient of thermal expansion (CTE) and improved mechanical properties films modified by carboxylated carbon nanotube (C-CNT) were fabricated. Acid treatment was adapted to adjust the surface characteristics by using a mixture of concentrated H₂SO₄/HNO₃ solution to introduce carboxyl groups on the surface and improve the interfacial performance between the CNT and matrix. Moreover, different C-CNT concentrations of 0, 1, 3, 5, 7, and 9 wt.% were synthesized to use for the PI film fabrication. The results demonstrated that the 9 wt.% and 5 wt.% C-CNT/PI films possessed the lowest CTE value and the highest mechanical properties. In addition, the thermal stability of the C-CNT/PI films was improved, making them promising applications in precise and harsh environments. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Graphical abstract

12 pages, 3211 KiB

Open AccessArticle

Reduction of Thermal Residual Strain in a Metal-CFRP-Metal Hybrid Tube Using an Axial Preload Tool Monitored through Optical Fiber Sensors

by Zhao Li, Wei Ke, Mingyao Liu and Yang Zhou

Polymers 2022, 14(20), 4368; https://doi.org/10.3390/polym14204368 - 17 Oct 2022

Viewed by 1656

Abstract

Thermal residual strains/stresses cause several defects in hybrid structures and various studies have reported the reduction of residual strain. This paper describes a method for reducing thermal residual strains/stresses in metal-CFRP-metal hybrid tubes (MCMHT). The proposed axial preload tool provides two ways to [...] Read more.

Thermal residual strains/stresses cause several defects in hybrid structures and various studies have reported the reduction of residual strain. This paper describes a method for reducing thermal residual strains/stresses in metal-CFRP-metal hybrid tubes (MCMHT). The proposed axial preload tool provides two ways to reduce the thermal residual strains/stresses during the co-cure bonding process: pre-compressing of the metal layers and pre-stretching of the unidirectional carbon fiber reinforced polymer (CFRP) layers. An online measurement technique with embedded optical fiber Bragg grating (FBG) sensors is presented. Thermal residual strains are evaluated based on classical lamination theory with the assumption of plane stress. The theoretical calculations and measurement results agree well. Furthermore, the dynamic characteristics of the MCMHTs are tested. The results show that the reduction of residual strain increases the natural frequency of the MCMHT, but is detrimental to the damping capability of the MCMHT, which imply that the intrinsic properties of the metal-composite hybrid structure can be modified by the proposed axial preload tool. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

12 pages, 4764 KiB

Open AccessArticle

Nitrogen-Doped Porous Core-Sheath Graphene Fiber-Shaped Supercapacitors

by Qianlan Ke, Yan Liu, Ruifang Xiang, Yuhui Zhang, Minzhi Du, Zhongxiu Li, Yi Wei and Kun Zhang

Polymers 2022, 14(20), 4300; https://doi.org/10.3390/polym14204300 - 13 Oct 2022

Cited by 9 | Viewed by 1535

Abstract

In this study, a strategy to fabricate nitrogen-doped porous core-sheath graphene fibers with the incorporation of polypyrrole-induced nitrogen doping and graphene oxide for porous architecture in sheath is reported. Polypyrrole/graphene oxide were introduced onto wet-spun graphene oxide fibers by dip-coating. Nitrogen-doped core-sheath graphene-based [...] Read more.

In this study, a strategy to fabricate nitrogen-doped porous core-sheath graphene fibers with the incorporation of polypyrrole-induced nitrogen doping and graphene oxide for porous architecture in sheath is reported. Polypyrrole/graphene oxide were introduced onto wet-spun graphene oxide fibers by dip-coating. Nitrogen-doped core-sheath graphene-based fibers (NSG@GFs) were obtained with subsequently thermally carbonized polypyrrole/small-sized graphene oxide and graphene oxide fiber slurry (PPY/SGO@GOF). Both nitrogen doping and small-sized graphene sheets can improve the utilization of graphene layers in graphene-based fiber electrode by preventing stacking of the graphene sheets. Enhanced electrochemical performance is achieved due to the introduced pseudo-capacitance and enhanced electrical double-layered capacitance. The specific capacitance (38.3 mF cm⁻²) of NSG@GF is 2.6 times of that of pure graphene fiber. The energy density of NSG@GF reaches 3.40 μWh cm⁻² after nitrogen doping, which is 2.59 times of that of as-prepared one. Moreover, Nitrogen-doped graphene fiber-based supercapacitor (NSG@GF FSSC) exhibits good conductivity (155 S cm⁻¹) and cycle stability (98.2% capacitance retention after 5000 cycles at 0.1 mA cm⁻²). Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

11 pages, 3382 KiB

Open AccessArticle

Enhancement of Piezoelectric Properties of Flexible Nanofibrous Membranes by Hierarchical Structures and Nanoparticles

by Feng Wang, Hao Dou, Cheng You, Jin Yang and Wei Fan

Polymers 2022, 14(20), 4268; https://doi.org/10.3390/polym14204268 - 11 Oct 2022

Cited by 1 | Viewed by 1836

Abstract

Piezoelectric nanogenerators (PENGs) show superiority in self-powered energy converters and wearable electronics. However, the low power output and ineffective transformation of mechanical energy into electric energy l limit the role of PENGs in energy conversion and storage devices, especially in fiber-based wearable electronics. [...] Read more.

Piezoelectric nanogenerators (PENGs) show superiority in self-powered energy converters and wearable electronics. However, the low power output and ineffective transformation of mechanical energy into electric energy l limit the role of PENGs in energy conversion and storage devices, especially in fiber-based wearable electronics. Here, a PAN-PVDF/ZnO PENG with a hierarchical structure was designed through electrospinning and a hydrothermal reaction. Compared with other polymer nanofibers, the PAN-PVDF/ZnO nanocomposites not only showed two distinctive diameter distributions of uniform nanofibers, but also the complete coverage and embedment of ZnO nanorods, which brought about major improvements in both mechanical and piezoelectric properties. Additionally, a simple but effective method to integrate the inorganic nanoparticles into different polymers and regulate the hierarchical structure by altering the types of polymers, concentrations of spinning solutions, and growth conditions of nanoparticles is presented. Further, the designed P-PVDF/ZnO PENG was demonstrated as an energy generator to successfully power nine commercial LEDs. Thus, this approach reveals the critical role of hierarchical structures and processing technology in the development of high-performance piezoelectric nanomaterials. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

27 pages, 4481 KiB

Open AccessArticle

Imitation of a Pre-Designed Irregular 3D Yarn in Given Fabric Structures

by Tianyong Zheng, Wenli Yue and Xiaojiao Wang

Polymers 2022, 14(19), 3992; https://doi.org/10.3390/polym14193992 - 23 Sep 2022

Viewed by 1562

Abstract

The 3D CAD software has obvious advantages in appearance imitating and geometric structure modeling for fabrics. In contemporary 3D CAD fabric systems, only uniform yarns are involved in studies on fabric geometric structures, due to technological limitations, whereas objectives such as irregular/uneven 3D [...] Read more.

The 3D CAD software has obvious advantages in appearance imitating and geometric structure modeling for fabrics. In contemporary 3D CAD fabric systems, only uniform yarns are involved in studies on fabric geometric structures, due to technological limitations, whereas objectives such as irregular/uneven 3D yarns have not been considered much. As the fabric structure or the central curve of the yarn changes, it is difficult to reflect the changed positions of the effect spots of the pre-designed uneven 3D yarns accordingly. In this paper, a key-point-mapping algorithm between the source yarn and the target curve is proposed to reflect the position change in effect spots when the fabric structure changes. By using the shape-preserving quasi-uniform cubic B-spline curve, a simple 3D irregular source yarn is designed using key points and setting their corresponding base cross-sections. The mapping is based on the principle that the lengths of the curve between the key points and the contours of the corresponding base cross-sections of the source yarn remain unchanged. Finally, the control grid of the new 3D yarn in the fabric structure is automatically generated. According to the examples and error analysis, the mapping technique can be applied to arbitrary given fabric structures, and the effect spots of the irregular 3D yarn are reasonably distributed as expected. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

10 pages, 2248 KiB

Open AccessCommunication

Precise Control of the Preparation of Proton Exchange Membranes via Direct Electrostatic Deposition

by Hao Liu, Runmin Tian, Chunxu Liu, Jinghan Zhang, Mingwei Tian, Xin Ning, Xingyou Hu and Hang Wang

Polymers 2022, 14(19), 3975; https://doi.org/10.3390/polym14193975 - 23 Sep 2022

Cited by 2 | Viewed by 1476

Abstract

In this work, we reported a novel preparation method for a proton exchange membrane (PEM) named, the direct electrostatic deposition method. In theory, any required thickness and size of PEM can be precisely controlled via this method. By direct electrostatic spraying of Nafion [...] Read more.

In this work, we reported a novel preparation method for a proton exchange membrane (PEM) named, the direct electrostatic deposition method. In theory, any required thickness and size of PEM can be precisely controlled via this method. By direct electrostatic spraying of Nafion solution containing amino modified SiO₂ nanoparticles onto a metal collector, a hybrid membrane of 30 μm thickness was fabricated. The DMFC assembled with a prepared ultrathin membrane showed a maximum power density of 124.01 mW/cm² at 40 °C and 100% RH, which was 95.29% higher than that of Nafion. This membrane formation method provides potential benefits for the preparation of ultrathin PEMs. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Graphical abstract

13 pages, 3137 KiB

Open AccessArticle

Vibrational Emission Study of the CN and C₂ in Nylon and ZnO/Nylon Polymer Using Laser-Induced Breakdown Spectroscopy (LIBS)

by Tahani A. Alrebdi, Amir Fayyaz, Amira Ben Gouider Trabelsi, Haroon Asghar, Fatemah H. Alkallas and Ali M. Alshehri

Polymers 2022, 14(17), 3686; https://doi.org/10.3390/polym14173686 - 5 Sep 2022

Cited by 9 | Viewed by 2261

Abstract

The laser-induced breakdown spectroscopy (LIBS) technique was performed on polymers to study the neutral and ionic emission lines along with the CN violet system (B²Σ⁺ to X²Σ⁺) and the C₂ Swan system (d³ П [...] Read more.

The laser-induced breakdown spectroscopy (LIBS) technique was performed on polymers to study the neutral and ionic emission lines along with the CN violet system (B²Σ⁺ to X²Σ⁺) and the C₂ Swan system (d³ П_g–a³ П_u). For the laser-based emission analyses, the plasma was produced by focusing the laser beam of a Q-switched Nd: YAG laser (2ω) at an optical wavelength of 532 nm, 5 ns pulse width, and a repetition frequency of 10 Hz. The integration time of the detection system was fixed at 1–10 ms while the target sample was positioned in air ambiance. Two organic polymers were investigated in this work: nylon and nylon doped with ZnO. The molecular optical emission study of nylon and doped nylon polymer sample reveals CN and C₂ molecular structures present in the polymer. The vibrational emission analysis of CN and C₂ bands gives information about the molecular structure of polymers and dynamics influencing the excitation structures of the molecules. Besides, it was further investigated that the intensity of the molecular optical emission structure strongly depends on the electron number density (cm⁻³), excitation temperature (eV), and laser irradiance (W/cm²). These results suggest that LIBS is a reliable diagnostic technique for the study of polymers regarding their molecular structure, identification, and compositional analysis. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Graphical abstract

13 pages, 4659 KiB

Open AccessArticle

Preparation and Photodegradation Properties of Carbon-Nanofiber-Based Catalysts

by Mingpan Zhang, Fuli Wang, Xinran Shi, Jing Wei, Weixia Yan, Yihang Dong, Huiqiang Hu and Kai Wei

Polymers 2022, 14(17), 3584; https://doi.org/10.3390/polym14173584 - 30 Aug 2022

Viewed by 1664

Abstract

In this study, an iron oxide/carbon nanofibers (Fe₂O₃/CNFs) composite was prepared by a combination of electrospinning and hydrothermal methods. The characterization of Fe₂O₃/CNFs was achieved via scanning electron microscopy (SEM), infrared spectroscopy (IR), X-ray diffraction [...] Read more.

In this study, an iron oxide/carbon nanofibers (Fe₂O₃/CNFs) composite was prepared by a combination of electrospinning and hydrothermal methods. The characterization of Fe₂O₃/CNFs was achieved via scanning electron microscopy (SEM), infrared spectroscopy (IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is shown that when the hydrothermal reaction time was 180 °C and the reaction time was 1 h, the Fe₂O₃ nanoparticle size was about 90 nm with uniform distribution. The photodegradation performance applied to decolorize methyl orange (MO) was investigated by forming a heterogeneous Fenton catalytic system with hydrogen peroxide. The reaction conditions for the degradation of MO were optimized with the decolorization rate up to more than 99% within 1 h, which can decompose the dyes in water effectively. The degradation process of MO by Fenton oxidation was analyzed by a UV-visible NIR spectrophotometer, and the reaction mechanism was speculated as well. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

15 pages, 5772 KiB

Open AccessArticle

An Optical Algorithm for Relative Thickness of Each Monochrome Component in Multilayer Transparent Mixed Films

by Meiqin Wu, Zuoxiang Lu, Yongrui Li, Xiaofei Yan, Xuefei Chen, Fangmeng Zeng and Chengyan Zhu

Polymers 2022, 14(16), 3423; https://doi.org/10.3390/polym14163423 - 22 Aug 2022

Cited by 1 | Viewed by 1494

Abstract

A modification of the two-flux Kubelka-Munk (K-M) model was proposed to describe the energy conservation of scattered light in colored mixed material with a defined scattered photometric, which is applied for the relative quantity distribution of each colored monochrome component in mixed material. [...] Read more.

A modification of the two-flux Kubelka-Munk (K-M) model was proposed to describe the energy conservation of scattered light in colored mixed material with a defined scattered photometric, which is applied for the relative quantity distribution of each colored monochrome component in mixed material. A series of systematical experiments demonstrated a higher consistency with the reference quantity distribution than the common Lambert-Beer (L-B) law. Its application in the fibrogram of each component for measuring the cotton fiber’s length was demonstrated to be good, extending its applicability to white and dark colored blended fibers, the length of which is harder to measure using L-B law. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

8 pages, 2938 KiB

Open AccessArticle

New Method for a SEM-Based Characterization of Helical-Fiber Nonwovens

by Ying Li, Guixin Cui and Yongchun Zeng

Polymers 2022, 14(16), 3370; https://doi.org/10.3390/polym14163370 - 18 Aug 2022

Cited by 2 | Viewed by 1768

Abstract

The lack of tools particularly designed for the quantification of the fiber morphology in nonwovens, especially the multi-level structured fibers, is the main reason for the limited research studies on the establishment of realistic nonwoven structure. In this study, two polymers, cellulose acetate [...] Read more.

The lack of tools particularly designed for the quantification of the fiber morphology in nonwovens, especially the multi-level structured fibers, is the main reason for the limited research studies on the establishment of realistic nonwoven structure. In this study, two polymers, cellulose acetate (CA) and thermoplastic polyurethane (TPU), which have different molecular flexibility, were chosen to produce nonwovens with helical nanofibers. Focusing on the nonwovens with helical fibers, a soft package was developed to characterize fiber morphologies, including fiber orientation, helix diameter, and curvature of helix. The novelty of this study is the proposal of a method for the characterization of nanofibrous nonwovens with special fiber shape (helical fibers) which can be used for curve fibers. The characterization results for the helical-fiber nonwoven sample and the nonwoven sample with straight fibers were compared and analyzed. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

14 pages, 6070 KiB

Open AccessArticle

A Highly Sensitive and Flexible Strain Sensor Based on Dopamine-Modified Electrospun Styrene-Ethylene-Butylene-Styrene Block Copolymer Yarns and Multi Walled Carbon Nanotubes

by Bangze Zhou, Chenchen Li, Zhanxu Liu, Xiaofeng Zhang, Qi Li, Haotian He, Yanfen Zhou and Liang Jiang

Polymers 2022, 14(15), 3030; https://doi.org/10.3390/polym14153030 - 26 Jul 2022

Cited by 7 | Viewed by 1986

Abstract

As wearable electronic devices have become commonplace in daily life, great advances in wearable strain sensors occurred in various fields including healthcare, robotics, virtual reality and other sectors. In this work, a highly stretchable and sensitive strain sensor based on electrospun styrene-ethylene-butene-styrene copolymer [...] Read more.

As wearable electronic devices have become commonplace in daily life, great advances in wearable strain sensors occurred in various fields including healthcare, robotics, virtual reality and other sectors. In this work, a highly stretchable and sensitive strain sensor based on electrospun styrene-ethylene-butene-styrene copolymer (SEBS) yarn modified by dopamine (DA) and coated with multi-walled carbon nanotubes (MWCNTs) was reported. Due to the process of twisting, a strain senor stretched to a strain of 1095.8% while exhibiting a tensile strength was 20.03 MPa. The strain sensor obtained a gauge factor (GF of 1.13 × 10⁵) at a maximum strain of 215%. Concurrently, it also possessed good stability, repeatability and durability under different strain ranges, stretching speeds and 15,000 stretching-releasing cycles. Additionally, the strain sensor exhibited robust washing fastness under an ultrasonic time of 120 min at 240 W and 50 Hz. Furthermore, it had a superior sensing performance in monitoring joint motions of the human body. The high sensitivity and motion sensing performance presented here demonstrate that PDA@SEBS/MWNCTs yarn has great potential to be used as components of wearable devices. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

17 pages, 39187 KiB

Open AccessArticle

Dynamic Equivalent Resistance Model of Knitted Strain Sensor under In-Plane and Three-Dimensional Surfaces Elongation

by Yutian Li, Pibo Ma, Mingwei Tian and Miao Yu

Polymers 2022, 14(14), 2839; https://doi.org/10.3390/polym14142839 - 12 Jul 2022

Cited by 1 | Viewed by 1556

Abstract

The dynamic equivalent resistance is a major index that determines the sensing performance of knitted strain sensors, and has the characteristics of in-plane and three-dimensional curved strain sensing. Therefore, in addition to establishing the in-plane equivalent resistance, it is necessary to establish a [...] Read more.

The dynamic equivalent resistance is a major index that determines the sensing performance of knitted strain sensors, and has the characteristics of in-plane and three-dimensional curved strain sensing. Therefore, in addition to establishing the in-plane equivalent resistance, it is necessary to establish a three-dimensional equivalent resistance model to fully explain the surface sensing performance. This project establishes two equivalent resistance models of knitted strain sensors under in-plane deformation and one equivalent resistance model of three-dimensional curved surface strain. Based on the length of resistance and the geometric topological structure, an in-plane strain macro–micro equivalent resistance model and a topological equivalent resistance model are established, respectively. In addition, a three-dimensional curved surface equivalent resistance model is created based on the volume resistance. By comparing the theoretical model with the experimental data, the results prove that the proposed in-plane and three-dimensional models can be utilized to calculate the resistance change of knitted strain sensors. Length resistance, coil transfer, and curved surface deformation depth are the main factors that affect the equivalent resistance of knitted strain sensors. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

12 pages, 7150 KiB

Open AccessArticle

Design and Analysis of Solid Rocket Composite Motor Case Connector Using Finite Element Method

by Lvtao Zhu, Jiayi Wang, Wei Shen, Lifeng Chen and Chengyan Zhu

Polymers 2022, 14(13), 2596; https://doi.org/10.3390/polym14132596 - 27 Jun 2022

Cited by 1 | Viewed by 2970

Abstract

The connector is an essential component in the solid rocket motor case (SRMC), and its weight and performance can directly affect the blasting performance of SRMC. Considering the lightweight design of these structures, fiber-reinforced composite materials are used for the major components. In [...] Read more.

The connector is an essential component in the solid rocket motor case (SRMC), and its weight and performance can directly affect the blasting performance of SRMC. Considering the lightweight design of these structures, fiber-reinforced composite materials are used for the major components. In this study, the finite element analysis of the SRMC connector was performed. The lay-up design and structure optimum design of the connector were studied. Furthermore, the strain distribution on the composite body was compared with experimental measurements. The results demonstrate that the calculated value of the final preferred solution was within the allowable range, and at least 31% weight loss was achieved, suggesting that the performance of the optimum design was optimized. The comparison between the finite element calculation and the test results suggests that the design was within the allowable range and reasonable. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

13 pages, 4149 KiB

Open AccessArticle

Size Prediction and Electrical Performance of Knitted Strain Sensors

by Xinhua Liang, Honglian Cong, Zhijia Dong and Gaoming Jiang

Polymers 2022, 14(12), 2354; https://doi.org/10.3390/polym14122354 - 10 Jun 2022

Cited by 10 | Viewed by 2061

Abstract

Benefitting from the multifunctional properties of knitted fabrics with elasticity, flexibility, and high resilience, knitted strain sensors based on structure and strain performance are widely utilized in sports health due to their adaptability to human movements. However, the fabrication process of common strain [...] Read more.

Benefitting from the multifunctional properties of knitted fabrics with elasticity, flexibility, and high resilience, knitted strain sensors based on structure and strain performance are widely utilized in sports health due to their adaptability to human movements. However, the fabrication process of common strain sensors mainly relies on experienced technicians to determine the best sensor size through repeated experiments, resulting in significant size errors and a long development cycle. Herein, knitted strain sensors based on plain knit were fabricated with nylon/spandex composite yarn and silver-plated nylon yarn using a flat knitting process. A size prediction model of knitted strain sensors was established by exploring the linear relationship between the conductive area size of samples and knitting parameters via SPSS regression analysis. Combined with stable structures and high performance of good sensitivity, stability, and durability, the knitted strain sensors based on size prediction models can be worn on human skin or garments to monitor different movements, such as pronunciation and joint bending. This research indicated that the reasonable size control of the knitted strain sensor could realize its precise positioning in intelligent garments, exhibiting promising potential in intelligent wearable electronics. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Graphical abstract

14 pages, 4022 KiB

Open AccessArticle

Research on Tensile Properties of Carbon Fiber Composite Laminates

by Jiayi Wang, Lifeng Chen, Wei Shen and Lvtao Zhu

Polymers 2022, 14(12), 2318; https://doi.org/10.3390/polym14122318 - 8 Jun 2022

Cited by 10 | Viewed by 4008

Abstract

In order to study the thread tensile performance of carbon fiber composite laminates, the connection between the test piece, connecting bolts, bushings, and the composite matrix, was leveraged for loading, and combined with an ultra-sound scanning imaging system, experiments were carried out on [...] Read more.

In order to study the thread tensile performance of carbon fiber composite laminates, the connection between the test piece, connecting bolts, bushings, and the composite matrix, was leveraged for loading, and combined with an ultra-sound scanning imaging system, experiments were carried out on the dynamic response to record the failure behavior of the laminate structure of equal thickness. The effects of different pull-off loading strengths on the dynamic failure process, deformation profile, midpoint deformation, failure mode, and energy dissipation ratio of the thread were studied. The results show that (1) with the increase in pull-off strength, the response speed of mid-point deformation increases, the thread deformation mode changes from overall deformation to partial deformation, and the localized effect increases, accompanied by severe matrix and fiber fracture failure; (2) the thread energy dissipation ratio ascends with increasing pull-off strength and exhibits three distinct stages, i.e., elastic deformation, central fracture, and complete failure, which are directly related to the structural failure mode; (3) the failure load increases with the increment of the thickness of the laminate, and the maximum failure surface of the specimen will move from the upper layer of the laminate to the lower layer along the thickness direction; (4) the deformation velocity of the midpoint augments with the increase in the tensile rate, which can be included as a factor to assess the tensile properties of carbon fiber composites. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

Review

Jump to: Research

21 pages, 3078 KiB

Open AccessReview

A Review of Recent Development of Wearable Triboelectric Nanogenerators Aiming at Human Clothing for Energy Conversion

by Yu Peng, Zheshan Wang, Yunfei Shao, Jingjing Xu, Xiaodong Wang, Jianchen Hu and Ke-Qin Zhang

Polymers 2023, 15(3), 508; https://doi.org/10.3390/polym15030508 - 18 Jan 2023

Cited by 12 | Viewed by 3593

Abstract

Research in the field of wearable triboelectric generators is increasing, and pioneering research into real applications of this technology is a growing need in both scientific and industry research. In addition to the two key characteristics of wearable triboelectric generators of flexibility and [...] Read more.

Research in the field of wearable triboelectric generators is increasing, and pioneering research into real applications of this technology is a growing need in both scientific and industry research. In addition to the two key characteristics of wearable triboelectric generators of flexibility and generating friction, features such as softness, breathability, washability, and wear resistance have also attracted a lot of attention from the research community. This paper reviews wearable triboelectric generators that are used in human clothing for energy conversion. The study focuses on analyzing fabric structure and examining the integration method of flexible generators and common fibers/yarns/textiles. Compared to the knitting method, the woven method has fewer restrictions on the flexibility and thickness of the yarn. Remaining challenges and perspectives are also investigated to suggest how to bring fully generated clothing to practical applications in the near future. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

13 pages, 2425 KiB

Open AccessReview

Personal Cooling Garments: A Review

by Song Ren, Mengyao Han and Jian Fang

Polymers 2022, 14(24), 5522; https://doi.org/10.3390/polym14245522 - 16 Dec 2022

Cited by 8 | Viewed by 6491

Abstract

Thermal comfort is of critical importance to people during hot weather or harsh working conditions to reduce heat stress. Therefore, personal cooling garments (PCGs) is a promising technology that provides a sustainable solution to provide direct thermal regulation on the human body, while [...] Read more.

Thermal comfort is of critical importance to people during hot weather or harsh working conditions to reduce heat stress. Therefore, personal cooling garments (PCGs) is a promising technology that provides a sustainable solution to provide direct thermal regulation on the human body, while at the same time, effectively reduces energy consumption on whole-building cooling. This paper summarizes the current status of PCGs, and depending on the requirement of electric power supply, we divide the PCGs into two categories with systematic instruction on the cooling materials, working principles, and state-of-the-art research progress. Additionally, the application fields of different cooling strategies are presented. Current problems hindering the improvement of PCGs, and further development recommendations are highlighted, in the hope of fostering and widening the prospect of PCGs. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

38 pages, 40633 KiB

Open AccessReview

Processes of Electrospun Polyvinylidene Fluoride-Based Nanofibers, Their Piezoelectric Properties, and Several Fantastic Applications

by Yubin Bai, Yanan Liu, He Lv, Hongpu Shi, Wen Zhou, Yang Liu and Deng-Guang Yu

Polymers 2022, 14(20), 4311; https://doi.org/10.3390/polym14204311 - 13 Oct 2022

Cited by 63 | Viewed by 4412

Abstract

Since the third scientific and technological revolution, electronic information technology has developed rapidly, and piezoelectric materials that can convert mechanical energy into electrical energy have become a research hotspot. Among them, piezoelectric polymers are widely used in various fields such as water treatment, [...] Read more.

Since the third scientific and technological revolution, electronic information technology has developed rapidly, and piezoelectric materials that can convert mechanical energy into electrical energy have become a research hotspot. Among them, piezoelectric polymers are widely used in various fields such as water treatment, biomedicine, and flexible sensors due to their good flexibility and weak toxicity. However, compared with ceramic piezoelectric materials, the piezoelectric properties of polymers are poor, so it is very important to improve the piezoelectric properties of polymers. Electrospinning technology can improve the piezoelectric properties of piezoelectric polymers by adjusting electrospinning parameters to control the piezoelectrically active phase transition of polymers. In addition, the prepared nanofibrous membrane is also a good substrate for supporting piezoelectric functional particles, which can also effectively improve the piezoelectric properties of polymers by doping particles. This paper reviews the piezoelectric properties of various electrospun piezoelectric polymer membranes, especially polyvinylidene fluoride (PVDF)-based electrospun nanofibrous membranes (NFs). Additionally, this paper introduces the various methods for increasing piezoelectric properties from the perspective of structure and species. Finally, the applications of NFs in the fields of biology, energy, and photocatalysis are discussed, and the future research directions and development are prospected. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

18 pages, 5872 KiB

Open AccessReview

Fabrication, Property and Application of Calcium Alginate Fiber: A Review

by Xiaolin Zhang, Xinran Wang, Wei Fan, Yi Liu, Qi Wang and Lin Weng

Polymers 2022, 14(15), 3227; https://doi.org/10.3390/polym14153227 - 8 Aug 2022

Cited by 44 | Viewed by 9129

Abstract

As a natural linear polysaccharide, alginate can be gelled into calcium alginate fiber and exploited for functional material applications. Owing to its high hygroscopicity, biocompatibility, nontoxicity and non-flammability, calcium alginate fiber has found a variety of potential applications. This article gives a comprehensive [...] Read more.

As a natural linear polysaccharide, alginate can be gelled into calcium alginate fiber and exploited for functional material applications. Owing to its high hygroscopicity, biocompatibility, nontoxicity and non-flammability, calcium alginate fiber has found a variety of potential applications. This article gives a comprehensive overview of research on calcium alginate fiber, starting from the fabrication technique of wet spinning and microfluidic spinning, followed by a detailed description of the moisture absorption ability, biocompatibility and intrinsic fire-resistant performance of calcium alginate fiber, and briefly introduces its corresponding applications in biomaterials, fire-retardant and other advanced materials that have been extensively studied over the past decade. This review assists in better design and preparation of the alginate bio-based fiber and puts forward new perspectives for further study on alginate fiber, which can benefit the future development of the booming eco-friendly marine biomass polysaccharide fiber. Full article

(This article belongs to the Special Issue Smart Textile and Polymer Materials)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Smart Textile and Polymer Materials

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Related Special Issue

Published Papers (22 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI