POLYMER
·
2022
·
IF 4.432
Can Zhou,Yangyang Zhang,Fangjie Cen,Xie Yu,Wenjing Zhou,Shenglin Jiang,Yan Yu
Polymer PTC (positive temperature coefficient) materials with low switching temperature point are important for many electronic devices since the electronic devices usually work under room temperature range (0–40 °C). The desired polymer PTC materials for the application in thermal control of flexible electronics should also include room-temperature switching temperature, low room-temperature resistivity, good mechanical flexibility and adaptive thermal control performances. This work designed two new types of PTC materials with room-temperature switching temperature and excellent mechanical properties . They are prepared by mixing the semi-crystalline polymer EVA with low melting temperature (Tm) with the amorphous polymer (PS or PVAc) with low glass transition temperature (Tg), while the low-cost graphite is selected as conductive filler. The PTC materials were obtained with low switching temperature point (<30 °C) and low room temperature resistivity (102 Ω m), high PTC repeatability and flexibility, short heating response time and good adaptive thermal control performances.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 34
·e54311
·
IF 3
Aimei Yu,Ying Xi,Weigang Xu,Ao Wang,Lin Liu,Lin Zhang
In this study, three kinds of newly flexible positive temperature coefficient (PTC) materials are fabricated by a simple preparation method. Due to introducing the hybrid filler of carbon nanotube and carbon black, these materials exhibit remarkable PTC effect including the PTC intensity of more than four-orders magnitude and the resistivity-temperature coefficient of 154%/°C. The Curie points of PTC materials are regulated to room-temperature range by the low melting phase and influenced by melting onset temperatures of their solid–liquid phase change. With the help of transmission electron microscope, the micro-capsule structure of the phase change regions is observed, and the hybrid conductive fillers randomly distribute in the blend matrix to construct three-dimensional conductive network. Using the PTC materials as a heating element, the equilibrium temperature of the controlled device can be maintained around their Curie point without any control method. Moreover, the adaptive thermal control effect becomes more obvious with the increase of ambient temperature and initial heating power. Furthermore, the thermal control accuracy fluctuates within 0.15°C without any external control method, and is improved to round 0.08°C in combination with the switch control method. This study provides a new method for the thermal control of electronic devices in the requirement of lightweight and miniaturization at low temperature environment.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2023
·
IF 4.6
Maozheng Wang,Xingliang Jiang,Yu Chen,Tao Li,Qiulin Chen,Longfei Ma
The application of the positive temperature coefficient (PTC) materials in electrothermal anti-icing offers not only uniform heating of the anti-icing area, but also adaptive temperature control of the material. This study focuses on the preparation of a low Curie point PTC material with a Curie temperature point of 1 °C, using the in-situ polymerization method. The PTC behaviors of the material were extensively investigated by adjusting the component ratios and the microstructures of the materials were analyzed in correlation with scanning electron microscopy (SEM) images. Subsequently, adaptive temperature control and stability experiments were conducted to evaluate the material's performance. Eventually, the material was adopted to electrothermal anti-icing experiment for wind turbine blades. The results demonstrate that when the mass fraction of acetylene black is 9 wt%, the mass ratio of n-tetradecane/hydroxyl-terminated polydimethylsiloxane (HTPDMS) is 1:1, and the mass ratio of polydimethylsiloxane (PDMS)/HTPDMS is 1:2, the low-temperature resistivity of the low Curie point PTC material reaches an impressive value of only 5.37 Ω cm, the PTC intensity can reach 2.99, and the thermal conductivity can reach 0.778 W/(m·K). Furthermore, the material exhibits robust adaptive temperature control capability, effectively maintaining the temperature below 3 °C under different operating voltages and ambient temperatures. Even after 100 cyclic experiments, the material demonstrates superior PTC behavior, excellent temperature control ability, and exceptional stability. Additionally, under different operating voltages, ambient temperatures and wind speeds, the low Curie point PTC material exhibits excellent adaptive adjustment capability and maintains uniform heating of the anti-icing surface. These findings provide valuable insights for in-depth exploration of the low Curie point PTC electrothermal anti-icing materials.
研究领域:
材料科学
·
能源工程
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2024
·Vol. 16
·期 14
·2028
·
IF 4.7
Chao Du,Yangyang Zhang,Jiangmin Lin,Guotao Fan,Can Zhou,Yan Yu
Polymeric positive temperature coefficient (PTC) materials with low switching temperature points are crucial for numerous electronic devices, which typically function within the room temperature range (0–40 °C). Ideal polymeric PTC materials for flexible electronic thermal control should possess a room-temperature switching temperature, low room-temperature resistivity, exceptional mechanical flexibility, and adaptive thermal control properties. In this study, a novel PTC material with a room-temperature switching temperature and superb mechanical properties has been designed. A blend of a semi-crystalline polymer EVA with a low melting temperature (Tm) and an amorphous polymer (PVAc) with a low glass transition temperature (Tg) was prepared. Low-cost graphite was chosen as the conductive filler, while CNF was incorporated as a hybrid filler to enhance the material’s heating stability. PVAc0.4/EVA0.6/GP-3wt.% CNF exhibited the lowest room temperature resistivity, and its PTC strength (1.1) was comparable to that without CNF addition, with a Curie temperature of 29.4 °C. Room temperature Joule heating tests revealed that PVAc0.4/EVA0.6/GP-3wt.% CNF achieved an equilibrium temperature of approximately 42 °C at 25 V, with a heating power of 3.04 W and a power density of 3.04 W/cm2. The Young’s modulus of PVAc0.4/EVA0.6/GP-3wt.% CNF was 9.24 MPa, and the toughness value was 1.68 MJ/m3, indicating that the elasticity and toughness of the composites were enhanced after mixing the fillers, and the mechanical properties of the composites were improved by blending graphite with CNF.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER BULLETIN
·
2022
·Vol. 80
·期 3
·2697-2711
·
IF 2.843
Yin Peinan,Wei Chengxiong,Jin Xin,Yu Xiaogang,Wu Chengwei,Zhang Wei
Trans-catheter arterial embolization, as a minimally invasive therapy strategy, has become a choice for treating liver cancer. Development of embolic agents integrated with therapy and imagining functions is desired. Herein, magnetic polyvinyl alcohol (PVA) microspheres as embolic agents are prepared by emulsification method. The diameter of the magnetic PVA microspheres ranges from 10 to 110 μm, and the required size can be obtained by sieving. The temperature of magnetic PVA microspheres suspension could stabilize at 49 °C under the applied magnetic field, which indicates the microspheres have self-regulating temperature hyperthermia characteristic due to the application of magnetic nanoparticles with low Curie point. In addition, magnetic PVA microspheres possess obvious contrast effects on CT and T2-weighted imaging due to the existence of magnetic nanoparticles. Cytotoxicity assay indicates the survival rate of cells cultured with leach liquor of 30 mg/mL PVA/MNPs microspheres is 97.4%, which shows the magnetic microspheres have good cell biocompatibility. The developed magnetic microspheres have the potential to realize embolization, self-regulating temperature hyperthermia, and CT/MR imaging simultaneously in interventional therapy.
研究领域:
医学成像
·
癌症治疗
·
生物医学工程
·
材料科学
✓ 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）