Polymers
·
2022
·Vol. 14
·期 7
·1413
·
IF 4.967
Yang Yang,Ziyuan Zheng,Jun Lin,Lintao Zhou,Guohua Chen
Polarizer is a key component of the liquid crystal display panel, and the optical properties mainly include transmittance, degree of polarization and chromaticity. Polarizer is made of a multilayer optical film, in which the PVA polarizing film is the core structure for realizing the polarization of the whole polarizer. PVA polarizing film is commonly manufactured through a multi-step craft, including rinsing, dyeing, stretching and correcting. The correction process has a significant impact on the final apparent color and optical properties of the polarizer. In this study, the KI concentration in the correcting tank, ranging from 1% to 3%, was systematically investigated. With the increase in KI concentration, the Raman vibration peak at 160 cm−1representingI5−ions gradually weakened, while the Raman vibration peak at 110 cm−1representingI3−ions gradually increased, indicating that the KI in the correcting tank changed the chemical equilibrium of polyiodide ions in PVA. Then abundant chromophoreI5−ions were consumed andI3−ions generated, so that the apparent color of PVA polarizing film gradually changed from dark blue to dark gray, and the chromaticitya-value andb-value gradually increased. The change in the concentration of dichroic species (I5−andI3−) in PVA polarizing film had directly affected its transmittance in the visible range. From the UV-Vis transmittance spectrum of PVA polarizing film, when theI5−ions were consumed andI3−ions generated, the transmittance of PVA polarizing film in the region of 675–525 nm wavelength increased gradually while the polarization degree also increased.Keywords:PVA polarizing film;correction process;transmittance;chromaticity;degree of polarization
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Jun-Heng Fu,Qigong Zhang,Minglei Yan,Wei Tang,Yun Zeng,Yuntao Cui,Mingkuan Zhang,Hongwei Deng,Hao Kang,Xinlong Sun,Liang Qiao,Hongzhang Wang,Yang Zhao
Passive radiative cooling which dissipates heat from surfaces by reflecting sunlight and emitting radiation towards outer space, has garnered growing attention as an eco-friendly cooling strategy with zero-energy consumption. However, few studies focus on low-cost and multifunctional composite film fabricated by a straightforward and environmentally friendly method that is crucial for their large-scale applications. Herein, we introduce a facile, efficient, and scalable approach to fabricate a hydrophobic and polymer-dielectric poly (vinylidene fluoride)-hexafluoropropylene (P(VDF-HFP)@PVA hydrogel Janus film (DPP), exhibiting exceptional radiative cooling and thermal management capabilities for diverse practical applications. With the introduction of ZnO, DPP showcases the optical capability with a solar reflectance of ≈93 % and an infrared emittance of ≈96 %, endowing it with remarkable radiative cooling performance. The synergistic integration of hydrogel phase change and radiation cooling capabilities offered by the P(VDF-HFP) layer enables the DPP to achieve a subambient cooling of 8.62 °C under direct sunlight. Moreover, when applied to the thermal management of electronic devices and fruit preservation due to the phase change property, the DPP effectively reduced surface temperatures by 10 °C and 15.5 °C respectively. Its simplicity and versatility suggest that it could be widely adopted for daytime passive radiation cooling, thereby expanding its practical applications across various fields.
研究领域:
材料科学
·
能源与环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Chenxiao Yin,Jingrui Sun,Wei Ni,Ling-Ying Shi
With the global energy shortage and deterioration of the human living environment as well as the increasing demand for personal protective equipment under extreme environments, phase change materials (PCMs) have received much attention due to their excellent energy storage and reusability. Herein, lithium nitrate trihydrate (LNH), one of the particularly promising low-temperature salt hydrate PCMs, was encapsulated with three-dimensional (3D) gelatin/polyvinyl alcohol (PVA) cross-linking networks to fabricate flexible, stretchable, and form-stable phase change salogels. Specifically, the salogels were fabricated by dissolving macromolecular gelatin and PVA in melted LNH and then cross-linked using 1,4-butanediol diglycidyl ether (BDDE). The encapsulation using a 3D cross-linked polymer network can effectively solve the problems of melting leakage/flowing and water-loss drying/hygroscopic deliquescence of LNH. The results showed that the gelatin/PVA/LNH salogels exhibit good form stability, high latent heat (~170.9 J g −1 ), and excellent hygroscopic properties with the saturation water absorption of dry gels up to 1.730 g g −1 . Meanwhile, the gelatin/PVA/LNH salogels show good mechanical properties, and their elongation at break could reach 1086%. Therefore, these hygroscopic phase change salogels are expected to be applicable in wearable devices for human low-temperature thermal and humidity management.
研究领域:
材料科学
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能源工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Membranes
·
2022
·Vol. 12
·期 3
·249
·
IF 4.562
Xin Rao,Qi Zhou,Qin Wen,Zhiqiang Ou,Lingying Fu,Yue Gong,Xueyu Du,Chunqing Huo
Plasma treatment is considered a straightforward, cost-effective, and environmental-friendly technique for surface modification of film materials. In this study, air plasma treatment was applied for performance improvement of pure PVA, cellulose nanocrystal (CNC)/PVA, and CNC/oxalic acid (OA)/PVA films. Compared with the original performance of pure PVA, the mechanical properties and water resistance of air plasma treated films were greatly improved. Among them, the CNC/OA/PVA film treated by three minutes of air plasma irradiation exhibits the most remarkable performance in mechanical properties (tensile strength: 132.7 MPa; Young’s modulus: 5379.9 MPa) and water resistance (degree of swelling: 47.5%; solubility: 6.0%). By means of various modern characterization methods, the wettability, surface chemical structure, surface roughness, and thermal stability of different films before and after air plasma treatment were further revealed. Based on the results obtained, the air plasma treatment only changed the surface chemical structure, surface roughness, and hydrophobicity, while keeping the inner structure of films intact.Keywords:air plasma;PVA film;surface modification;water resistance;crosslinking
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2021
·Vol. 101
·期 1
·103-113
·
IF 2.326
Wang Chen,Shen Zhifeng,Hu Pengfei,Wang Tao,Zhang Xing,Liang Lidong,Bai Jianguang,Qiu Liewei,Lai Xiaojuan,Yang Xiaowu,Zhang Kang
Borax-PVA hydrogels with excellent mechanical properties are prepared by simple physical mixing of polyvinyl alcohol (PVA, thickener) and borax (cross-linking agent) at room temperature. The resulting hydrogel is a three-dimensional structure composed of boric ester bonds as physical crosslinking points. Thus, the spatial structure, swelling properties, viscoelastic properties, tensile properties, and self-healing properties of hydrogels with different ratios of borax and PVA are studied. XRD confirmed that the hydrogels have similar structures near 2 θ values of 10 and 20. The microstructure of the hydrogel is confirmed by SEM and TEM. With an increase of borax mass fraction, the pore structure and morphology of hydrogel are more ordered, with substantial quantities of water immobilized within their three-dimensional structure. The viscoelastic properties and tensile properties showed that when the mass fraction of borax is 5%, the storage modulus and compressive stress of the hydrogel are the highest, reaching 100 Pa and 5.6 kPa, respectively. In addition, through physical and chemical stimulation (heating and varying pH, respectively), the hydrogels also showed reversible gel–sol conversion characteristics, indicating that the boric ester bonds have self-healing properties.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FIBERS AND POLYMERS
·
2024
·Vol. 25
·期 6
·2131-2138
·
IF 2.2
Wang Peng,Jin Zengkai,Mai Ke,Zhu Lei,Lin Junxiong
The antibacterial silver nanoparticles (Ag NPs)-loaded cotton fabric modified by SPEEK/PVA film was prepared by photo-induced method with 350 nm UV light irradiation. Its wearable properties, such as wrinkle recovery, tensile property, thermal stability and water vapour permeability were investigated. It was found that the fabric loaded with Ag NPs retained its brown colour after five cycles of washing in soap solution. TG/DTG analysis indicated that the fabric had two pyrolysis peak temperatures at about 370 °C and 500 °C, and the loading of Ag NPs improved the thermal stability of the cotton fabric. The crease recovery angles of the fabric in both warp and weft directions increased with the generation of Ag NPs. However, both the breaking force and elongation at break decreased with the generation of Ag NPs due to the use of UV irradiation, which is destrimental to the mechanical performance of textile materials. Moreover, the deposition of Ag NPs led to a minor decrease of the water-vapour transmission rate. The hand-feel evaluation showed that the softness of the fabric improved whilst the smoothness declined with the loading of Ag NPs. The water contact angle was found to be 135.2°, indicating that the Ag NPs-loaded cotton fabric had excellent hydrophobicity.
研究领域:
材料科学
·
纺织工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Fang Li,Jianfeng Ye,Linming Yang,Chunhua Deng,Qing Tian,Bo Yang
Due to the ease of processing and stability during filtration, polydopamine (PD) coatings with grafted hydrophilic polymers have recently received significant attention. In this study, glycine-functionalized PVA was synthesized and grafted to a PD-coated ultrafiltration (UF) membrane to improve its performance during wastewater filtration. The membranes were modified by grafting PD with glycine-functionalized PVA (PD-g-PVA), and the resultant materials were characterized using surface morphology analyses, contact angle measurements, flux, oil/water emulsion separation tests, and grafted layer stability tests. The performance of the PD-g-PVA membrane was compared to that of the membrane modified with PD-g-polyethylene glycol (PEG). After grafting the PD-g-PVA, the surface roughness of the membranes decreased significantly. The grafted PVA layer, which was stable under acidic and alkaline conditions, protected the PD layer. The filtration experiments with an oil/water emulsion indicated that modifying the glycine-functionalized PVA by grafting can significantly improve the antifouling ability of membranes.
研究领域:
材料科学
·
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 54
·34416-34423
·
IF 3.361
Zhenzeng Wu,Tingjie Chen,John Tosin Aladejana,Zhutao Zhang,Shengwei Liang,Yuanjiao Xiao,Jiahui Lin,Xiaodong(Alice) Wang,Yongqun Xie
Aluminum phosphate (AP) shows great potential to replace formaldehyde-based adhesives in the wood industry, except for its weak hygroscopic resistance and low wet bonding strength. This study chose PVA as an AP modifier to prepare a PVA–AP organic–inorganic hybrid adhesive (PAP). The preparation, bonding mechanism and heat resistant property of PAP were studied by using X-ray photoelectron spectroscopy (XPS), Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TG-DSC), nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). The result showed that covalent bonds between PVA and AP were built. The mechanical properties of PAP improved remarkably; the dry and wet bonding strength are 2.28 and 0.79 MPa with 15.2% and 690% increment, respectively, compared to the control samples. The thermostabilities of PAP and plywood samples were improved. In conclusion, PVA could effectively improve the hygroscopic resistance and low wet bonding strength of AP adhesives.
研究领域:
材料科学
·
林学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Lisha Pu,Zhiang Yuan,Yuting Cai,Xusheng Li,Zhongxin Xue,Yuzhong Niu,Yan Li,Songmei Ma,Wenlong Xu
Currently, the development of hydrogels with excellent mechanical properties (elasticity, fatigue resistance, etc.) and conductive properties can better meet their needs in the field of flexible sensor device applications. Generally, hydrogels with a denser cross-linking density tend to have better mechanical properties, but the improvement in mechanical properties comes at the expense of reduced electrical conductivity. Directly generating CaCO3 in the hydrogel prepolymer can not only increase the cross-linking density of its network but also introduce additional ions to enhance its internal ionic strength, which is beneficial to improving the conductivity of the hydrogel. It is still a big challenge to directly generate CaCO3 in the static prepolymer solution and ensure its uniform dispersion in the hydrogel. Herein, we adopted an improved preparation method to ensure that the directly generated CaCO3 particles can be evenly dispersed in the static prepolymer solution until the polymerization is completed. Finally, a PAM/PVA/CaCO3 hydrogel with supertensile, compressive, toughness, and fatigue resistance properties was prepared. In addition, the presence of free Na+ and Cl– gives the hydrogel excellent conductivity and sensing performance to monitor daily human activities. On the basis of the application of hydrogels in information communication, we have further deepened this application by combining the characteristics of hydrogels themselves. Combined with ASCII code, the hydrogel can also be applied in information exchange and information encryption and decryption, achieving the antitheft function in smart locks. A variety of excellent performance integrated PAM/PVA/CaCO3 hydrogels have broad application prospects for flexible sensors, highlighting great potential in human–computer interaction and intelligent information protection.
研究领域:
材料科学
·
生物医学工程
·
智能材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2024
·Vol. 62
·期 15
·3346-3359
·
IF 3.9
Xiaohui Wang,Yarui Hou,Yiyuan Fan,Zeqi Liu,Ran Li,Xiaojun Li,Bin Yang,Qingye Liu
Soft tissues, such as muscle could autonomously grow through re-alignment and/or -combination of collagen nanofibrils upon the mechanical training. This adaptive capability is highly expected in artificial materials, particularly in hydrogel actuator. In order to avoid the failure for devices by suffering from the accumulated mechanical loading, in this work, a double layered thermo-responsive hydrogel actuator capable of self-strengthening was successfully prepared. In the bilayer, PVA nanocrystals with different particle sizes were uniformly distributed in each monolayer matrix, giving rise to the asymmetric structure and the resultant differentiated de-swelling behaviors. Thus, the obtained hydrogel actuator with the semi-interpenetrating network of P(NIPAM-co-NMA) can display diverse programmable transformations by varying the temperatures. The existence of PVA nanocrystals in both layers not only can enhance the mechanical strength, dramatically minimizing the collapse of hydrogel actuator in service due to the imbalance of the mechanical properties for bilayer structure, but also was greatly involved in the self-reinforcing behavior. After repetitive tensile training with 80% strain, the tensile strength and fracture strain increased from 29.6 to 45.8 kPa and 95% to 104%, respectively. The experimental results indicated that the anisotropic orientation and strain-induced-crystallization for PVA crystalline domains readily occurred along the tensile direction, finally leading to the synchronous enhancement in mechanical strength for both layers. This work provides a new strategy for designing smart and robust biomimetic hydrogel systems that can be further used as the intelligent soft robotics in various fields. Graphical
研究领域:
材料科学
·
生物仿生学
·
软体机器人
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 14
·18591-18604
·
IF 2.478
Zhang Shengsheng,Huang Fanglin,Zhong Mingqiang,Fan Ping
Dielectric material is an important material for film capacitors. However, the progress of this material is either impeded by its low dielectric constant, high loss tangent, or insufficient flexibility. In this work, PVA/GO film with alternating layer structure was fabricated by Spin-Coating-Assembly (SCA) method. This alternating layer structure not only benefits forming numerous microscale capacitors which improve ε value a lot, but also helps eliminate perpendicular contact of GO and prevents the formation of conductive pathways. Thus, compared with pure PVA, significantly increased dielectric permittivity and a low loss tangent were simultaneously observed for the PVA/GO film. The ratio of dielectric permittivity to loss tangent increased from 68 to 165. These films might be potential flexible dielectric materials for advanced electrical devices such as embedded capacitors.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
AUSTRALIAN JOURNAL OF CHEMISTRY
·
2022
·Vol. 75
·期 10
·820-834
·
IF 1.224
Haikuan Yuan,Cun Bao,Ruiran Hao,Jie Lu
A polyvinyl alcohol (PVA)/SiO2 organic-inorganic hybrid membrane was fabricated, using PVA as the basic material, SiO2 nanoparticles as the inorganic material, γ-(2,3)-glycidoxy propyl trimethoxysilane (GPTMS) and 3-aminopropyl triethoxysilane (APTEOS) as the second modified agents. The dehydration performance of PVA-SiO2/polyacrylonitrile (PAN) composite membrane to ethyl acetate (EA)/H2O, EA/ethanol (EtOH)/H2O and EA/EtOH/acetic acid (HAc)/H2O solutions was investigated. After modification of the second coupling agent of APTEOS or GPTMS, PVA-SiO2/PAN composite membrane had the better dehydration performance to these aqueous solutions. When dehydrating PVA-SiO2/PAN composite membrane modified by GPTMS (M5 membrane) in EA/H2O binary solution (98/2, wt%) at 40°C, the separation factor and the total permeation flux were 5245 and 293.9 g m−2 h−1, respectively. The preparation method of PVA/SiO2 membrane through adding the second coupling agent was simple, it had good dehydration performance and has excellent application prospects. The sorption behavior of PVA/SiO2 hybrid membrane was systematically studied, providing sufficient data for studying the separation mechanism of pervaporative membrane. The degree of swelling (DS) and the sorption selectivity of the membrane in different feed compositions and temperatures were measured to determine the static sorption of membrane. Dynamic sorption more clearly reflects the sorption and swelling processes of the membrane, and the dynamic sorption curves of the membrane in EA aqueous solutions were obtained. The sorption behavior of membrane to permeate components was studied by ATR-FTIR. Changes in the characteristic peaks for the permeate components and membrane indicated the sorption behavior of the membrane.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）