聚酰亚胺基导热绝缘复合薄膜的研究进展

聚酰亚胺(PI)薄膜作为综合性能最优异的聚合物材料之一,已经被广泛应用于各类微电子器件。随着电子元器件的功率密度急剧增加,热积累问题已经成为制约其发展的瓶颈。具有高导热性能的PI绝缘薄膜材料被认为是解决上述热积累问题的有效方法之一。由于PI薄膜的本征导热性能较差,近年来,国内外研究学者在提高PI薄膜导热性能方面做了大量工作。本文从阐述热量在PI薄膜中的传输机理出发,概述了近年来导热PI绝缘薄膜的研究进展与发展现状,重点讨论了绝缘导热型填料、导电导热型填料以及三维导热骨架等增强PI绝缘复合薄膜导热性能的策略,最后对PI基导热绝缘复合薄膜研究进展和未来可能的发展趋势进行了总结和展望。     

导热橡胶研究进展北大核心CSCD

橡胶是热的不良导体,但在实际应用中,许多领域需要橡胶具备一定的导热性能,以满足使用要求。因此,人们对于橡胶导热的研究越来越重视。本文概述了导热填料种类、形状、粒径、界面结合状态以及填料在橡胶基体中的分散性等因素对橡胶复合材料导热性能的影响,从实验角度分析了填充型导热橡胶的导热机理,阐述了目前研究中人们所建立的各种物理和数学模型,浅析了这些模型的优缺点及适用范围,并将其应用于橡胶材料导热性能的预测,最后介绍了导热橡胶的应用领域,以及导热橡胶未来的发展方向。     

甲烷水合物导热机理的分子动力学模拟

甲烷水合物导热系数是甲烷水合物勘探、开采、储运以及其他应用过程中一个十分重要的物理参数.我们采用平衡分子动力学（EMD）方法Green-Kubo理论计算温度203.15～263.15K、压力范围3～100MPa、晶穴占有率为0～1的sI甲烷水合物的导热系数,采用的水分子模型包括TIP4P、TIP4P-Ew、TIP4P-FQ、TIP4P/2005、TIP4P/Ice.研究了主客体分子、外界温压条件等对甲烷水合物导热性能的影响.研究结果显示甲烷水合物的低导热性能由主体分子构建的sI笼型结构决定,而客体分子进入笼型结构后,使得笼型结构导热性能增强,同时进入笼型结构的客体分子越多,甲烷水合物导热性能越强.研究结果还显示在高温区域（T〉TDebye/3）内不同温度作用下,所有sI水合物具有相似的导热规律.压力对导热系数有一定影响,尤其是在较高压力条件下,压力越高,导热系数越大.而在不同温度和不同压力作用过程中,密度的改变对导热系数的增大或减小几乎没有影响.     

耐高温高导热硅橡胶的研究与应用进展

概述了导热硅橡胶的种类、组成、固化机理和应用及发展方向。分析了硅橡胶的热老化机理,概述了几种提高硅橡胶耐热老化性能的方法,指出添加含杂原子聚硅氧烷是提高硅橡胶耐热性和综合性能的一条非常重要的有效途径。同时系统阐述了导热硅橡胶的导热理论和机理及提高硅橡胶导热性的方法,概述了导热填料的种类、晶体结构、粒径及制法、取向和纤维化及表面处理和复合杂化对硅橡胶导热性能的影响。     

高分子导热复合材料结构设计及性能研究进展

近年来,电子设备的需求逐渐向集成化、微型化发展,随之带来了愈发严重的发热问题已经成为了阻碍电子设备发展的重要因素之一。作为电子设备重要组成材料之一的高分子材料对优良导热性能的要求也越来越高,导热高分子复合材料的研究已经成为当前功能复合材料的重要发展方向。本文综述了高分子导热复合材料的发展趋势,介绍了当前选用填料法来制备单一填料、混杂填料高分子导热复合材料以及双逾渗结构、隔离结构等复杂多相结构的高分子导热复合材料的研究进展。重点介绍了通过多种导热填料的组合利用来制备高性能导热高分子复合材料。最后,对填料法高导热高分子复合材料的发展方向做出了简要展望。     

氮化硼/聚合物导热复合材料研究进展

电子信息产业的高速发展,使得电子装置或装备在使用过程中产生的热量越来越剧烈,需要及时导出以保证其正常运行,聚合物基导热复合材料由于其优异的加工性和较低的成本得到了应用。六方氮化硼(hBN)兼具优异的导热性和绝缘性,因此作为导热填料在导热绝缘聚合物复合材料领域受到越来越多的关注。本文主要从氮化硼填料尺寸、表面性质、取向结构以及杂化等方面综述了近年来氮化硼/聚合物导热复合材料的研究进展。     

填料填充型聚合物基导热材料的研究进展

大多数聚合物由于导热性差等缺点,限制了其在许多领域的应用,因此需要添加导热填料增强聚合物的导热性能,提高材料的使用价值.但是导热填料难以均匀分散到聚合物中,极大地制约了其在高性能热界面材料中的应用,所以需要对填料进行表面功能化,提高其分散性和降低填料与基体之间的界面热阻.无论表面功能化的类型如何,不可避免地都会减弱填料...     

兼具导热和自修复功能的聚合物复合材料

针对聚合物复合材料存在的结构受损导致导热和力学强度降低的问题,提出利用导热填料增强自修复聚合物,实现导热性能和力学强度的快速修复.通过对双(3-氨丙基)封端的聚二甲基硅氧烷(H2N-PDMS-NH2)进行端基改性,得到脲基嘧啶酮(UPy)双封端的聚二甲基硅氧烷(UPy-PDMS-UPy),于60℃下20 h后拉伸强度修复效率可达86.6%.进一步填充羟基化氮化硼(mBN)制备兼具自修复功能的导热复合材料,研究发现mBN的填充导致复合材料强度提高但韧性降低,对导热性能和自修复功能分别起积极和不利影响.当mBN含量为30 wt%时,热导率高达2.579 W·m^?1·K^?1,于60℃下40 h后拉伸强度修复效率达82.0%.红外热像仪显示,损伤处接触10 h后,mBN-30/UPy-PDMS-UPy上表面温度接近初始温度,展现出导热通路的修复特征,实现导热与自修复功能的兼备.     

导热橡胶研究进展

橡胶是热的不良导体,但在实际应用中,许多领域需要橡胶具备一定的导热性能,以满足使用要求。因此,人们对于橡胶导热的研究越来越重视。本文概述了导热填料种类、形状、粒径、界面结合状态以及填料在橡胶基体中的分散性等因素对橡胶复合材料导热性能的影响,从实验角度分析了填充型导热橡胶的导热机理,阐述了目前研究中人们所建立的各种物理和数学模型,浅析了这些模型的优缺点及适用范围,并将其应用于橡胶材料导热性能的预测,最后介绍了导热橡胶的应用领域,以及导热橡胶未来的发展方向。     

石蜡/膨胀石墨/石墨烯复合相变储热材料的制备及性能

以石蜡(PA)作为相变储热材料、 膨胀石墨(EG)作为主导热材料和支撑材料, 石墨烯气凝胶(GA)作为导热增强材料和辅支撑材料制备了PA/EG/GA复合相变材料, 研究了GA添加量对复合相变材料相变温度、 相变潜热、 导热性能以及循环稳定性的影响. 结果表明, 所制备的80%PA-17%EG-3%GA复合相变材料导热性能良好, 循环稳定性出色. 与80%PA-20%EG复合材料相比, 该材料的相变温度、 相变潜热以及循环稳定性无明显变化, 但导热系数由4.089 W/(m·K)提升到了5.336 W/(m·K), 显示出良好的应用前景.     

A Fast and Room-temperature Self-healing Thermal Conductive Polymer Composite

Thermal conducting materials may be damaged during long-term use, resulting in the increase of thermal resistance and therefore inefficient heat dissipation. The introduction of self-healing ability may solve this problem, but the realization of fast and room-temperature selfhealing in thermal conducting composites is quite challenging. Herein, we choose a flexible poly(dimethylsiloxane) polymer material(PDMSCOOH) as the matrix and graphene nanosheets as the thermal conductive filler to prepare a new kind of thermal conductive polymer composite(PDMS-COOH-CG) that can quickly self-heal at room temperature. The thermal conductivity of PDMS-COOH-CG10 with 10% of graphene content is 0.48 W·m~(-1)·K~(-1), which is 16 times that of PDMS-COOH(0.03 W·m~(-1)·K~(-1)). At room temperature, self-healing efficiency of PDMS-COOHCG10 based on tensile strength can be 53.8% for 30 s and 84.6% for 24 h. Dynamic infrared thermal imaging dipicted that after 2 min of selfhealing at room temperature, the thermal conduction temperature near the damage was basically restored to the level of the pristine sample.     

石墨烯导热研究进展

石墨烯具有目前已知材料中最高的热导率,在电子器件、信息技术、国防军工等领域具有良好的应用前景。石墨烯导热的理论和实验研究具有重要意义,在最近十年间取得了长足的发展。本文综述了石墨烯本征热导率的研究进展及应用现状。首先介绍应用于石墨烯热导率测量的微纳尺度传热技术,包括拉曼光谱法、悬空热桥法和时域热反射法。然后展示了石墨烯热导率的理论研究成果,并总结了石墨烯本征热导率的影响因素。随后介绍石墨烯在导热材料中的应用,包括高导热石墨烯膜、石墨烯纤维及石墨烯在热界面材料中的应用。最后对石墨烯导热研究的成果进行总结,提出目前石墨烯热传导研究中存在的机遇与挑战,并展望未来可能的发展方向。     

聚苯胺复合材料的制备方法及应用进展

复合材料是由两种或多种性质不同的物质组成的多元材料,具有比各组分材料更优异的或原来不具备的性能。聚苯胺(PANI)作为最具应用前景的导电高分子材料,国内外对基于PANI的复合材料的研究也愈加关注。本文对PANI复合材料制备方法的研究成果进行了综述,主要包括原位化学法、共混法、电化学法、层层自组装法等。探讨了PANI复合材料在电极、导电、防腐、传感、分离、催化等方面的应用性能,并展望了PANI复合材料今后研究与应用的发展方向。     

塑料及其复合材料的摩擦学

综述了近年来国内外塑料及其复合材料的摩擦学研究的新进展,涉及到PTFE、PEEK、UHMWPE的合金以及塑料复合材料的重点研究领域,指出基于现代材料设计的摩擦学材料设计、塑料在热和应力作用下的蠕变和长期稳定性、塑料梯度功能材料和环保的绿色材料的摩擦学等方面是未来的发展方向。     

Electrically conductive nanocomposites with segregated structure based on poly(vinylidene fluoride-<Emphasis Type="Italic">co</Emphasis>-tetrafluoroethylene) and reduced graphene oxide

An approach was described to obtaining polymer composites with segregated structure that have high electrical conductivity at low concentrations of an electrically conductive filler. According to this approach, thin layers of electrically nonconductive nanodispersed graphene oxide are applied to the surface of polymer particles and conduction is produced by heat and chemical treatments. Hot pressing of the modified powder leads to combination of layers of the graphene-like filler to form a single electrically conductive network. For the first time, reduction of graphene oxide on the surface of polymer particles with hydrazine vapor at room temperature was performed. Comparison of the electrical conductivities of composites obtained by the thermal and chemical methods of graphene oxide reduction showed that the chemical reduction method gives composites with higher conductivities than the thermal method does. The maximum conductivity (0.5 S/m) was reached in a composite containing 0.6% chemically reduced graphene oxide.     

聚合物太阳能电池研究进展

有机材料是近年来新型太阳能电池的研究热点,本文按太阳能电池材料的组成分类,对太阳能电池的原理及其材料的种类进行了详细地总结,重点介绍了导电聚合物基的太阳能电池的研究进展.     

Tailoring the Thermal Conductivity of Rubber Nanocomposites by Inorganic Systems: Opportunities and Challenges for Their Application in Tires Formulation

The development of effective thermally conductive rubber nanocomposites for heat management represents a tricky point for several modern technologies, ranging from electronic devices to the tire industry. Since rubber materials generally exhibit poor thermal transfer, the addition of high loadings of different carbon-based or inorganic thermally conductive fillers is mandatory to achieve satisfactory heat dissipation performance. However, this dramatically alters the mechanical behavior of the final materials, representing a real limitation to their application. Moreover, upon fillers’ incorporation into the polymer matrix, interfacial thermal resistance arises due to differences between the phonon spectra and scattering at the hybrid interface between the phases. Thus, a suitable filler functionalization is required to avoid discontinuities in the thermal transfer. In this challenging scenario, the present review aims at summarizing the most recent efforts to improve the thermal conductivity of rubber nanocomposites by exploiting, in particular, inorganic and hybrid filler systems, focusing on those that may guarantee a viable transfer of lab-scale formulations to technological applicable solutions. The intrinsic relationship among the filler’s loading, structure, morphology, and interfacial features and the heat transfer in the rubber matrix will be explored in depth, with the ambition of providing some methodological tools for a more profitable design of thermally conductive rubber nanocomposites, especially those for the formulation of tires.     

Achieving a high thermal conductivity for segregated BN/PLA composites via hydrogen bonding regulation through cellulose network

Normally, the effective dispersion of thermal conductive fillers is a prerequisite for ensuring thermally conductive networks formed in polymer composites. In this work, a facile method was provided by using cellulose to alter the distribution state of boron nitride (BN) for the preparation of high thermally conductive polylactic acid (PLA). After powder mixing and hot‐pressing process, the Cellulose@BN was located at the boundaries of PLA granules to form consecutive thermally conductive networks with more compact structure. Morphology observation and FTIR spectra confirmed that BN edges absorbed on the cellulose surface under the intermolecular hydrogen bond interaction between PLA and BN. At the BN content of 25 wt%, contrasted with traditional BN/PLA segregated polymer composites (SPCs), thermal conductivity coefficient of Cellulose@BN/PLA SPCs improved by 53.5% from 0.71 to 1.09 Wm^?1 K^?1. This enhancement could be attributed to the reason that the cellulose regulated stripe aggregation allowed the BN connect with each other more compact, thus a thermal conduction networks with reduced phonon scattering were formed.     

RD496微热量计的研制及其应用

简要回顾了热导式微热量计的建立和发展,着重介绍了RD496微热量计的研制历程.归纳并介绍了RD496微热量计在化学和材料研究中的应用,包括物质晶型转化温度和转化热、溶解热和混合热、生成反应焓的测定,化学反应热动力学、稀释结晶动力学的研究,比热容和固体材料导热系数的测定,材料原位生长的量热研究和材料的微量吸附量热研究等;另外,对于其在高分子化学及物理、生物化学及农业科学等方面的应用进行了叙述.     

Multifunctional Thermally Conductive Composite Films Based on Fungal Tree-like Heterostructured Silver Nanowires@Boron Nitride Nanosheets and Aramid Nanofibers

Thermal conduction for electronic equipment has grown in importance in light of the burgeoning of 5G communication. It is imperatively desired to design highly thermally conductive fillers and polymer composite films with prominent Joule heating characteristics and extensive mechanical properties. In this work, “solvothermal & in situ growth” method is carried out to prepare “Fungal tree”-like hetero-structured silver nanowires@boron nitride nanosheet (AgNWs@BNNS) thermally conductive fillers. The thermally conductive AgNWs@BNNS/ANF composite films are obtained by the method of “suction filtration self-assembly and hot-pressing”. When the mass fraction of AgNWs@BNNS is 50 wt%, AgNWs@BNNS/ANF composite film presents the optimal thermal conductivity coefficient of 9.44 W/(m ⋅ K) and excellent tensile strength of 136.6 MPa, good temperature-voltage response characteristics, superior electrical stability and reliability, which promise a wide application potential in 5G electronic devices.