石墨烯增强复合相变储能材料的热学性能研究

以铁尾矿多孔陶瓷为载体,通过自发浸渗法成功制备出了添加石墨烯的复合相变储能材料,并对该材料热学性能及稳定性进行测试。结果表明：通过改变载体孔隙率,可以制得导热系数为0.41～0.59 W/(m·K)、潜热为69～120 kJ/kg、热学稳定性良好的导热增强复合相变储能材料。通过拟合,复合相变储能材料的导热系数与多孔载体的孔隙率呈线性关系,且经100次热循环后材料熔化潜热和导热系数分别降低了3.2%和16.7%。本研究为固废铁尾矿在蓄热、储能领域的应用提供了新思路。     

石蜡复合相变材料的研究进展及其热学性质

石蜡作为相变储能材料具有不存在过冷及析出现象,性能稳定,无毒,无腐蚀,价格便宜等优点。石蜡复合相变储能材料弥补了石蜡作为相变储能材料的缺点,改进了在实际应用中相变材料的效果,并且扩大了石蜡相变储能材料应用的领域。主要介绍了国内外对石蜡复合相变储能材料的研讨及相关热学性质。     

Eco-Friendly Electromagnetic Interference Shielding Materials from Flexible Reduced Graphene Oxide Filled Polycaprolactone/Polyaniline Nanocomposites

Hybrid nanocomposites have the unique ability of enhancing material properties due to the existing synergistic effect of the fillers. In this study, the authors report such an eco-friendly hybrid nanocomposite comprising of polyaniline and reduced graphene oxide in polycaprolactone. The conducting polyaniline improved the processability of polycaprolactone, and the final composites were prepared by incorporating graphene oxide reduced at 200 and 600°C temperatures to the polycaprolactone–polyaniline blend. Polyaniline, polyaniline/reduced graphene oxide200, and polyaniline/reduced graphene oxide600 imparted good electrical conductivity to polycaprolactone, and the fabricated flexible polycaprolactone–polyaniline/reduced graphene oxide nanocomposites exhibited good mechanical property, increased thermal stability, and excellent electromagnetic interference shielding up to 42 dB at 13 GHz.     

石蜡定形相变材料的包裹及热性能

利用原位聚合法,提出了对定形相变材料进行无机高分子材料再包裹,制备了硅胶封装石蜡定形相变材料的微胶囊,其石蜡的含量最高达到w(石蜡)=69.12%。用差示扫描量热仪(DSC)测定了微胶囊的热性能,并将测定粉体材料润湿性能的W ashburn方程应用于相变材料的亲油亲水性测定,评价了定形相变材料在胶囊封装前后的亲水性变化。结果表明,经硅胶封装的相变材料其相变焓为153.46 J.g-1,相变焓降低较少,而亲水性能有很大提高,确定了微胶囊产品中石蜡最佳质量分数为w(石蜡)=50%~56%。     

Large-Scale Fabrication of Flexible EVA/EG@PW Phase Change Composites with High Thermal Conductivity for Thermal Management

The working electronic devices and batteries generate a lot of heat, if this heats not release quickly, it will not only have a great impact on the performance of the devices, but also cause certain safety hazards. The passive thermal management based on organic phase change materials (PCMs) stands out due to its excellent temperature regulation capability as well as the buffer protection capability for device overload. In view of these, a series of flexible EVA/EG@PW (EE@P) phase change composites (PCCs) with high thermal conductivity are prepared by efficiently constructing porous skeletons and thermal conductive pathways through sacrificial template method, and introducing paraffin wax (PW) by simple vacuum impregnation technique. The PCC exhibits high thermal conductivity (2.6 W m⁻¹ K⁻¹), high enthalpy (153.5 J g⁻¹), and good flexibility. In addition, the PCC possesses excellent cycling stability and thermal stability. In practical application, the PCC shows good temperature control ability for LED and shows great potential application in the field of thermal management.     

复合相变储热材料的研究与发展

系统概括和评述了复合相变材料的制备方法及其研究进展，并介绍了研制有机／无机纳米复合相变储热材料的创新思路及初步研究成果，提出，有机／无机纳米复合技术是制备高性能复合相变储热材料的新途径。     

相变储能材料的研究进展

综述了用于节能领域的相变储能材料的分类及其性能、优缺点;重点论述了新型相变材料的研究发展;并探讨了相变材料在太阳能利用、医疗、建筑节能等领域的应用;展望了未来相变材料的发展方向和应用前景。     

相变材料的研究与应用新进展

综述了近年来相变材料的研究和应用状况,包括相变材料的封装和热性能研究进展,以及在许多领域的应用,展望了相变材料的发展前景.     

Tailoring Nylon 6/Acrylonitrile-Butadiene-Styrene Nanocomposites for Application against Electromagnetic Interference: Evaluation of the Mechanical,Thermal and Electrical Behavior,and the Electromagnetic Shielding Efficiency

Nylon 6/acrylonitrile-butadiene-styrene nanocomposites were prepared by mixing in a molten state and injection molded for application in electromagnetic interference shielding and antistatic packaging. Multi-wall carbon nanotubes (MWCNT) and maleic anhydride-grafted ABS compatibilizer were incorporated to improve the electrical conductivity and mechanical performance. The nanocomposites were characterized by oscillatory rheology, Izod impact strength, tensile strength, thermogravimetry, current-voltage measurements, shielding against electromagnetic interference, and scanning electron microscopy. The rheological behavior evidenced a severe increase in complex viscosity and storage modulus, which suggests an electrical percolation phenomenon. Adding 1 to 5 phr MWCNT into the nanocomposites produced electrical conductivities between 1.22 × 10⁻⁶ S/cm and 6.61 × 10⁻⁵ S/cm. The results make them suitable for antistatic purposes. The nanocomposite with 5 phr MWCNT showed the highest electromagnetic shielding efficiency, with a peak of –10.5 dB at 9 GHz and a value around –8.2 dB between 11 and 12 GHz. This was possibly due to the higher electrical conductivity of the 5 phr MWCNT composition. In addition, the developed nanocomposites, regardless of MWCNT content, showed tenacious behavior at room temperature. The results reveal the possibility for tailoring the properties of insulating materials for application in electrical and electromagnetic shielding. Additionally, the good mechanical and thermal properties further widen the application range.     

应用于功能性热流体的相变微胶囊的制备与表征

相变材料微胶囊以其特有的蓄热性能在热能存储领域引起了人们的广泛关注。以异佛尔酮二异氰酸酯和四乙撑五胺为壁材原料,以相变点为20℃的石蜡为芯材,以非离子表面活性剂span60和tween60为乳化剂,利用界面聚合法制备了应用于功能热流体的相变微胶囊,分别用相差显微镜和差示扫描量热分析仪测定了微胶囊的形貌和热性能,结果表明所得微胶囊粒径分布均匀,其直径约为1.7μm。芯材含量约为92.4%,颗粒均匀,相变热124.47 J/g。相变微胶囊热稳定性高,具有好的致密性和不溶胀性。     

Ultrasonic-Assisted Method for the Preparation of Carbon Nanotube-Graphene/Polydimethylsiloxane Composites with Integrated Thermal Conductivity,Electromagnetic Interference Shielding,and Mechanical Performances

Due to the rapid development of the miniaturization and portability of electronic devices, the demand for polymer composites with high thermal conductivity and mechanical flexibility has significantly increased. A carbon nanotube (CNT)-graphene (Gr)/polydimethylsiloxane (PDMS) composite with excellent thermal conductivity and mechanical flexibility is prepared by ultrasonic-assisted forced infiltration (UAFI). When the mass ratio of CNT and Gr reaches 3:1, the thermal conductivity of the CNT-Gr(3:1)/PDMS composite is 4.641 W/(m·K), which is 1619% higher than that of a pure PDMS matrix. In addition, the CNT-Gr(3:1)/PDMS composite also has excellent mechanical properties. The tensile strength and elongation at break of CNT-Gr(3:1)/PDMS composites are 3.29 MPa and 29.40%, respectively. The CNT-Gr/PDMS composite also shows good performance in terms of electromagnetic shielding and thermal stability. The PDMS composites have great potential in the thermal management of electronic devices.     

癸酸-棕榈酸/SiO2复合相变材料的热性能

以SiO2为载体、癸酸-棕榈酸为相变材料,采用溶胶-凝胶法制备癸酸-棕榈酸/SiO2复合相变材料,考察了其储热性能、导热性能、微观形貌和组成结构. 结果表明,当癸酸-棕榈酸掺入量为0.08 mol时,所制材料具有最好的潜热性能,相变温度为20.02~22.08℃,相变焓为44.53~50.51 J/g,适合在建筑领域应用;当癸酸-棕榈酸掺入量为0.06 mol时,材料导热性能最好,导热系数在第一降温阶段为0.211 W/(m×K),相变平台阶段为0.017 W/(m×K),第二降温阶段为0.040 W/(m×K);材料中SiO2与癸酸-棕榈酸仅是物理嵌合,未发生明显的化学作用,癸酸-棕榈酸掺杂过量时明显包裹SiO2,导致复合相变材料潜热性能和导热性能下降.     

微胶囊相变材料及其在热红外隐身中的应用

微胶囊相变材料是将微胶囊技术应用到相变材料中而形成的新型功能材料,因其独特的功能而成为近年来材料研究的热点。综述了微胶蠼相变材料及其在热红外隐身上的应用,展望了其在热红外隐身上的应用前景。     

Synergistic Function between Phosphorus-Containing Flame Retardant and Multi-Walled Carbon Nanotubes towards Fire Safe Polystyrene Composites with Enhanced Electromagnetic Interference Shielding

As a universal polymer material, polystyrene (PS) is widely applied in electrical devices and construction. Thus, it is necessary to improve the flame retardancy and electromagnetic shielding properties of PS material. In this work, PS/silicon-wrapped ammonium polyphosphate/Inorganic acid-treated multi-walled carbon nanotubes composites (PS/SiAPP/aMWCNT, abbreviated as PAC) were prepared via methods of filtration-induced assembly and hot-pressing. Morphology and structure characterization demonstrated that SiAPP and aMWCNT had good dispersion in PS and excellent compatibility with the PS matrix. Thermogravimetric analysis revealed that the addition of aMWCNT to PS improved its thermal stability and carbon-forming characteristics. The peak heat release rate, the peak carbon monoxide production rate, and the peak smoke production rate of the PAC10 composite decreased by 53.7%, 41.9%, and 45.5%, respectively, while its electromagnetic shielding effectiveness reached 12 dB. These enhancements were attributed to the reason that SiAPP and aMWCNT synergistically catalyzed the char generation and SiAPP produced free radical scavengers and numbers of incombustible gases, which could decrease the oxygen concentration and retard the combustion reaction. Therefore, the assembled PS/SiAPP/aMWCNT system provides a new pathway to improve the flame retardant and electromagnetic shielding properties of PS.     

石蜡/LDPE/OMMT/石墨复合相变储能材料的制备及性能

以石蜡为相变材料,低密度聚乙烯(LDPE)为支撑材料,有机蒙脱土(OMMT)为载体材料,石墨为填料,采用加热共熔法制备石蜡/LDPE/OMMT/石墨复合相变储能材料。采用扫描显微镜(SEM)、红外光谱仪(FTIR)、热重分析仪(TGA)、差示扫描量热仪(DSC)、广角X射线衍射仪(WAXD)、导热系数测定仪等对复合相变材料进行结构表征与性能测试。结果表明:当石蜡质量分数为50%,OMMT质量分数为15%,石墨质量分数为4%时,石蜡包覆良好,相变温度为57.45℃,相变潜热为92.95 J/g。该复合相变材料结构稳定、密封性能优异、热稳定性好和导热率高,应用前景广阔。     

多孔SiC陶瓷/石蜡复合相变材料定型封装及热性能研究

以微米级SiC粉为原料,采用冷冻干燥工艺制备具有连贯层状孔结构的SiC陶瓷。以多孔SiC陶瓷为基体,石蜡为相变芯材,通过真空浸渍法制备多孔SiC陶瓷/石蜡复合相变材料,研究了石蜡在层状多孔SiC陶瓷内的浸渗行为及复合材料的储热性能。结果表明,层片状多孔SiC陶瓷的显微形貌对石蜡的浸渗过程及储热性能有明显影响。当石蜡负载量为21.7%(质量分数)时,复合相变材料熔融温度为59.6 ℃,凝固温度为53.9 ℃,相变潜热为28.4 J/g,室温下的热导率为2.4 W·(m·K)^-1。复合相变材料吸热峰和放热峰强度随着石蜡负载量减少而降低,当温度为200 ℃时,多孔SiC陶瓷/石蜡复合相变材料失重为5%(质量分数),表明材料具有良好的热稳定性。复合相变材料在100 ℃热处理30 min后陶瓷基体未发生形变,经100次热循环后具有稳定的相变潜热和良好的定型能力。     

相变材料在动力电池热管理系统中的应用进展

动力电池作为电动汽车的核心部件对整车的性能有很大影响,而其性能的发挥又受工作温度影响,只有确保在一定的温度范围内动力电池的性能才能最好的发挥.因此动力电池组必须安装有效的热管理系统,保证正常的工作温度,缩小单体电池的温差.相变材料是一种可以被用于热管理系统的新型材料,本文分别从相变材料的性能、动力电池热管理系统现状和相变材料在动力电池热管理系统中的应用三个方面对基于相变材料的热管理系统进行了综述.     

相变材料在纺织品中的研究和应用进展

介绍了常用相变材料,相变材料与纤维或纺织品结合的四种主要方法即直接纺丝法、交联沉积法、微胶囊化法、复合纺丝法,重点是微胶囊法和复合纺丝法,含有相变材料纺织品的产品测试标准仪器也有涉及。     

膨胀石墨相变储热复合材料的制备及性能研究

利用石墨高温膨胀得到多孔高吸附性膨胀石墨,吸附石蜡相变材料,制备了膨胀石墨石蜡相变储热复合材料。采用扫描电镜、差示扫描量热分析对复合材料的结构和性能进行了表征,研究了其储热释热行为。结果表明,在900℃时保持32 s膨胀后可得到适宜的膨胀石墨,吸附适量石蜡时仍保持定型特性,石墨的添加改善了复合材料的导热性能,提高了相变...     

高分子固-固相变材料的热性能

以活性炭颗粒(ACG)为吸附增强材料,高密度聚乙烯(HDPE)、聚乙二醇(PEG)为相变材料,采用物理共混法制备两种高分子固-固相变材料。利用差示扫描量热仪、导热系数测定仪、高温综合热分析仪对所得相变材料的热性能进行了研究。结果表明:入活性炭颗粒,可提高材料的导热系数和热稳定性。