Research progress of thermally conductive polymer composites with three-dimensional interconnected network structures
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摘要: 热界面材料可以有效地将高温电子器件的热量快速传递到热管理元件，以缓解电子器件过热而导致的元件寿命恶化的问题。近年来，由聚合物和高导热填料制成的聚合物基复合材料因其密度低、导热性能可调而受到广泛关注。不同于传统的填料随机分散的复合材料，在聚合物基体中构建三维连续网络结构可以显著增加填料/填料接触、降低导热渗透阈值和界面热阻，显著改善复合材料的导热性能。首先，简要分析了聚合物基导热复合材料的导热机制。其次，总结了具有连续网络结构的聚合物基导热复合材料的构筑工艺，主要包括基于三维导热填料网络的预构筑、基于聚合物颗粒/粉末的后加工、基于聚合物纤维/织物的后加工、基于聚合物胶乳的铸膜或絮凝等工艺。再次，系统总结了不同类型的导热填料对聚合物复合材料导热性能的影响，主要包括金属填料、陶瓷填料、碳基填料及其混杂填料等。最后，对具有三维连续网络结构的聚合物基导热复合材料的发展前景进行了展望。Abstract: Thermal interface materials could effectively transfer the heat from electronic devices with high temperature to the thermal management components, so as to alleviate the problems of deterioration of component life caused by overheating of electronic devices. In recent years, the polymer-based composites composed of polymer matrix and reinforcing fillers with high thermal conductivities have been widely concerned because of their low density and adjustable thermal conductivities. Different from the conventional composites with randomly dispersed fillers, the construction of three-dimensional (3D) continuous network structure in the polymer matrix could significantly increase the filler/filler contact, reduce the percolation threshold of thermal conductivity and the interfacial thermal resistance, and then significantly improve the thermal conductivities of composites. Firstly, the thermal conductivity mechanisms of polymer-based thermal conductive composites were briefly analyzed. Secondly, the construction processes of polymer-based thermally conductive composites with interconnected network structures were summarized, mainly including the pre-construction of 3D thermally conductive filler network, the post-processing based on polymer particle/powder, the post-processing based on polymer fiber/fabric, and the film casting or flocculation based on polymer latex. The effects of different types of thermal conductive fillers on the thermal conductivities of polymer composites were summarized, mainly including metal fillers, ceramic fillers, carbon-based fillers and their hybrid fillers. Finally, the development prospects of polymer-based thermally conductive composites with interconnected network structures were prospected.
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随着时代的发展，大量的电磁波产生于商业、工业和军事应用中，无形的电磁波正在侵袭着人们的正常生活[1-3] ，并且逐渐导致一系列环境和社会安全问题。值得注意的是，电磁波吸收器能够有效地减弱或者消除入射电磁波的电磁能量，特别是不同频率的电磁辐射(尤其是在2~18 GHz范围内)，能够将其转化为热能或其他形式的能量，这被认为是消除电磁波辐射的简单可行的解决方案[4-6]。近年来，微波吸收剂种类越来越多，但大多数吸收剂由于其复杂的合成工艺和昂贵的原材料阻碍了它们的实际应用，相比之下，从自然资源中转化而来的生物质碳(BDC)材料，由于其丰富的资源和便捷的合成，能够以对待环境友好的方式大量获取[7-8]。生物质衍生碳拥有分层级结构、多孔结构[9]和网状结构中存在的微观结构能够提供丰富的界面极化和偶极极化位点，有利于形成2D/3D导电网络，提高材料的电磁波吸收能力[10]。
生物质衍生碳作为典型的介电损耗型吸波材料，具有低密度、高导电性和良好的化学稳定性，但单一的损耗型机制无法满足各个频段电磁波的有效地吸收[11]。同时，单组分生物质衍生碳的磁损耗性能较差，阻抗匹配较低，进而限制了单组分生物质衍生碳材料的发展。因此，可以通过对碳材料表面进行改性，或者与磁性组分结合来改善复合材料的阻抗特性和吸波性能[12]。Dong等[13]以可持续生物质香蒲为模板，合理构建了分级钉状碳纤维/ZnO纳米棒复合材料，当填充率仅为15wt%时，分级钉状碳纤维@ZnO在2.29 mm的匹配厚度下，在14.12 GHz下表现出−62.35 dB的较高的反射损耗，分级钉状碳纤维的中空结构和互连导电网络的结构有助于传导损耗和多次反射；Yan等[14]以香蒲绒毛为模板，通过绿色、简单的合成工艺，构建出管状碳纤维/镍纳米粒子复合材料，其中原位生长的镍纳米粒子的均匀分布提供了磁耦合网络，并与碳纤维形成丰富的异质界面，以增强界面极化，促进了复合材料的有效吸收带宽；Dong等[15]通过水热和碳化方法制备了爆米花衍生的蜂窝状的多孔碳杂化物，通过调整碳化温度，材料厚度为1.57 mm，其反射损耗可达−52.97 dB，吸收带宽为4.8 GHz，其高效的吸收特性归因于NiS2/SnS2纳米粒子对碳组分的有效调控，因而复合材料的阻抗匹配特性大幅度的提升。由此可见生物质衍生碳在结合上磁性组分或者表面改性后，能够很大程度的改善复合碳材料的阻抗匹配特性，其独特的多孔结构也能够为纳米磁性颗粒提供大量的活性位点，增加了界面极化效应的可能性，从而微波吸收能力能够得到较大的提高。
磁性材料固有的磁特性能够促进低频电磁波吸收并优化阻抗匹配[16] ，材料的组成和结构是影响吸波性能的重要因素。通常通过合适的组分配比和添加磁性掺杂物等手段，来实现介电常数和复磁导率的平衡，以达到最佳的吸波性能，因此具有磁损耗和介电损耗的轻质碳材料是比较有前途的制备吸波剂的方法[17]。本课题通过在碳基体上随机分布的磁性颗粒(Fe)制备了具有磁性碳复合吸收剂。
基于此，研究采用一种简单的碳热还原的方法，以生物质香蒲为原料，利用其固有的吸附特性，经原位吸附和高温煅烧还原得到了Fe/C复合材料，受介电-磁损耗机制的协同增强，Fe/C复合材料具有优异的吸波性能，其最大反射损耗值在4.4 GHz处可达−35 dB，研究将为生物质衍生碳基吸波材料提供新的策略。
1. 实验部分
1.1 原材料
香蒲，淘宝购买；FeCl3·6H2O(AR，99.0%)和尿素购自上海阿拉丁生化科技股份有限公司； 氩气(99.99%，河南源正特种气体有限公司)，去离子水和工业乙醇。
1.2 试样制备
将0.5 g香蒲、100 mL 0.50 mol/L的尿素溶液和100 mL 1 mol/L的六水合三氯化铁混合在一起搅拌24 h后抽滤，再将香蒲转移至真空烘箱50℃烘干，制得浅黄色前驱体，经氩气气氛以升温速率5℃/min高温煅烧还原2 h制备出Fe/C复合材料，将经过700℃、800℃、900℃的材料分别命名为Fe/C-700、Fe/C-800和Fe/C-900(表1)，制备流程如图1(a)所示，图1(d)为Fe/C-700、 Fe/C-800 和Fe/C-900吸波样品的制备流程图。本次制备采用了30%的填料量(石蜡质量为0.06 g、样品质量为0.025 g)，后经石蜡充分搅拌和研磨使复合材料粉末均匀地分散到圆环中。
表 1 Fe/C复合材料的命名Table 1. Naming of Fe/C compositesSample Calcination temperature/℃ Fe/C-700 700 Fe/C-800 800 Fe/C-900 900 ![]()
图 1 Fe/C复合材料的制备流程图 (a)、SEM图像 ((b)~(c))、吸波测试样品制备流程图 (d)、XRD图谱 (e)、热重图谱 (f)、拉曼图谱 (g)、 振动样品磁强计(VSM) (h)Figure 1. Fe/C composite preparation flow chart (a), SEM images ((b)-(c)), flow chart for sample preparation for wave absorption testing (d), XRD (e), TG (f), Raman mapping (g), vibrating sample magnetometer (VSM) (h)ID/IG—Intensity ratio of the D band and G band1.3 表征与测试
实验采用日本HITACHI公司扫描电子显微镜(SEM，S-4800型)，调整放大倍数可以观察到样品的形貌和结构；利用X射线衍射仪(XRD，U1tima IV，日本，Cu-Kα辐射，扫描速度10/min)对材料组分、晶体结构或粒径等信息进行分析；热重测试采用德国NETZSCH公司热重分析仪器(TG，209FI Iris)。通过热重分析材料的热稳定性，确定煅烧温度及分析物理化学反应；X射线光电子能谱分析仪(XPS)采用美国热电公司(ESCALAB 250Xi)，用来测定材料中元素构成、试验式及其中所含元素化学态和电子态的定量能谱技术。磁性测试采用美国Lake Shore公司振动样品磁强针，对材料的磁特性进行分析的仪器；利用Agilent 8720B矢量网络分析仪( 集成信号源，动态范围为95 dB)在微波暗室内采用同轴法进行涂层吸 波性能测试, 测试频率范围为2~18 GHz，真空烘箱采用上海精宏实验设备有限公司(DZF-6020)。
2. 结果与讨论
2.1 Fe/C复合材料的形貌、成分及其性质
图1(b)为煅烧后没有经过负载的香蒲纤维。煅烧后的香蒲纤维呈现出竹节状，能够更大程度地增加比表面积，使负载效果更佳；图1(c)可以看出Fe纳米粒子成功负载到了碳层上，碳层较大的表面积为磁性颗粒增加了更多的活性位点[18]，可以有效地避免磁性颗粒的团聚，同时能够有效地增加复合材料的导电性，有利于电子的快速传输[10]；附着在碳层表面的颗粒平均尺度大约为0.25 μm，呈现出不规则形状的纳米颗粒是通过Fe3+还原沉淀而成；在外电场的作用下，大量的Fe单质和碳层之间产生了许多的异质界面，由于二者的导电性和介电特性的不同，额外电荷将聚集在它们之间的界面上，从而导致界面极化的发生[19]，使复合材料的电磁波吸收能力进一步得到提升。
图1(e)是不同煅烧温度下复合材料的XRD图谱。Fe/C复合材料在3个不同温度下煅烧，700℃、800℃、900℃煅烧的样品衍射峰分别位于2θ=44.8°、65.0°和82.3°，分别对应于体心立方Fe单质的PDF(JCPDS No.06-0696)的(110)、(200)和(211)平面[20]，特征峰的出现表明存在不含任何杂质的Fe单质，证实在C的存在下Fe/C复合材料中三价铁离子被完全还原成金属铁，并且金属粒子可以增加复合材料的磁损耗机制。Fe/C-800特征峰较另外两个样品特征峰十分尖锐，说明Fe/C-800中Fe的结晶度较高；并且复合材料在2θ=26°出现随温度升高逐渐凸显的鼓包峰，对应于石墨碳的(002)平面[4]。
为了评估Fe/C复合材料的热稳定性能，利用热重分析仪将复合材料在空气氛围中进行高温热分解，从图1(f)中可以看出，复合材料在空气氛围下经历了一个明显的失重区。第一个质量下降过程裂解温度小于400℃时，是由于复合材料表面上少量的吸附水受热蒸发，Fe/C-700、Fe/C-800、Fe/C-900复合材料分别损失7.86wt%、4.6wt%、4.8wt%；Fe/C-700、Fe/C-800、Fe/C-900复合材料在500℃开始剧烈失重，复合材料失重率分别为50%、60%和80%，这是由于复合材料中的碳在高温空气下被迅速燃烧，直至800℃后趋于稳定；Fe/C-700、Fe/C-800、Fe/C-900复合材料的剩余质量分别为14.15wt%、51.5wt%和40.1wt%。结合式(1)，估算得到Fe/C复合材料Fe元素含量分别为12.0wt%、43.0wt%、33.0wt%，其中W为剩余质量百分数，M为化合物相对分子质量。由此可知Fe/C-800复合材料中的Fe元素含量最高，在最终形成了氧化产物中残余质量最大。
WR=(1−Wcarbon−Wwater)M(Fe2O3)2M(Fe) (1) 为了进一步确定复合材料中Fe元素含量，对其进行电感耦合等离子体(ICP)测试，确定出Fe/C-700、Fe/C-800、Fe/C-900复合材料Fe元素含量分别为38.5874 、490.7882 、192.6471 mg/g，与热重分析所得结果一致。
复合材料中碳组分的石墨化程度会对其介电损耗和电磁波吸收性能产生重要的影响，较高石墨化程度可以增强碳组分的电导损耗[21]，用拉曼对Fe/C复合材料的石墨化程度进行分析，从图1(g)拉曼图谱可以看出，在1350 cm−1(D带)和1590 cm−1(G带)出现两个明显的峰，D带与C原子晶格缺陷有关，而G带与C原子sp2杂化的面内伸缩振动有关[13]，其比值ID/IG值常用来表征碳材料的石墨化程度，所得Fe/C复合材料中的碳材料应为部分石墨化的碳材料，Fe/C-700、Fe/C-800和Fe/C-900的ID/IG的比值分别为0.92、0.87和0.91，从比值上看复合材料Fe/C-800的石墨化强度大于Fe/C-900，是由于在煅烧过程中，材料中的有机物会发生热解和氧化反应，从而导致材料中的碳元素逐渐向石墨化方向发展。但是，在高温下，氧化反应也会被加速，从而使材料中的碳元素被氧化成为气态化合物而流失。同时，煅烧过程中还会形成多种杂质和晶格缺陷，这些杂质和缺陷会影响材料的导电性能和吸波性能，从而影响材料的石墨化程度，Fe/C-800材料ID/IG比值较小，证明其复合材料的石墨化程度最强，复合材料的介电性能越好，这主要得益于高温煅烧的铁/碳复合材料中无定形碳向石墨转化。
通过振动样品磁强计可以测定Fe/C复合材料的饱和磁化强度(Ms)和矫顽力(Hc)。从图1(h)所示，不同温度下的复合材料有相似的曲线趋势图，三者均表现出了铁磁性质，700℃、800℃、900℃的Fe/C复合材料的饱和磁化强度(Ms)分别为52.09 emu/g、96.66 emu/g、51.52 emu/g，可以看出Fe/C-800饱和磁化强度(Ms)最大，根据TG测试结果分析可知Fe/C-800复合材料中Fe组分含量最高，以往文献分析可知，磁性组分的含量大小影响着复合材料的饱和磁化强度大小[22]，铁/碳复合材料的区域扩大磁滞曲线如图1(e)内插图所示，通过分析发现，在Fe/C-700、Fe/C-800和Fe/C-900的Hc依次为2077.56、1106.44和1599.96 kA/m，一般来说，复合材料的矫顽力通常受磁各向异性、形状各向异性和颗粒尺寸等因素影响， 复合材料中Fe纳米颗粒均为相同的面心立方结构，微观形貌均为片状，因此矫顽力受颗粒尺寸影响较大，对于Fe/C-700、Fe/C-800，Ms增加，Hc降低，是铁纳米粒子的生长过程中通过表层的自旋斜切效应导致的[23]，Fe/C-700和Fe/C-900 的复合材料的饱和磁化强度非常接近，是由于复合材料中Fe纳米粒子中在煅烧中，经炉体环境的影响造成了Fe纳米粒子在微观环境的自旋造成，并且饱和磁化强度决定于组成材料的磁性原子数、原子磁矩和温度。但在低温区，它遵循布洛赫(Bloch)定律，使Fe/C-700复合材料的饱和磁化强度同Fe/C-900非常接近。
图2展示了Fe/C-700、Fe/C-800和Fe/C-900复合材料的的氮气吸附/脱附等温线图(BET)。等温线显示具有典型H3磁滞回线的IV型等温线，表明复合材料具有介孔结构； Fe/C-700、Fe/C-800和Fe/C-900 BET比表面积(SBET)分别为478.6 m2·g−1、543.56 m2·g−1和589.04 m2·g−1，高比表面积进一步印证了材料的多孔结构，适宜的多孔结构为延长电磁波传输提供更多空间。同时，孔径分布图证实材料的介孔特性，Fe/C-800和Fe/C-900复合材料孔径主要分布于3~10 nm之间，进而调节复合材料等效电磁参数以优化材料阻抗匹配。
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图 2 Fe/C-700 (a)、Fe/C-800 (b)、Fe/C-900 (c) 的BET曲线Figure 2. BET curves of Fe/C-700 (a), Fe/C-800 (b), Fe/C-900 (c)STP—Standard temperature and pressure利用XPS对Fe/C复合材料元素种类及其表面化学价态进行表征。Fe/C复合材料XPS全谱如图3(a)所示，在284.08、399.08、531.08、713.05 eV周围有5个不同的峰，分别归属于C1s、N1s、O1s、Fe2p；C1s高分辨率XPS图谱图3(b)显示复合材料存在C—C/C=C(283.88 eV)峰，C—N(285.18 eV)峰和C—O(287.18 eV)[24]；如图3(c)所示，N1s光谱在398.28、399.78、400.48和402.68 eV处分为4个峰，属于吡啶N、吡咯N、石墨N和氧化N，石墨氮的形成有助于提高复合材料的电导率[25-27]；Fe2p高分辨率XPS图谱如图3(d)所示，其中在位于709.48 和722.58 eV处的峰可归属于Fe2p3/2和Fe2p1/2，712.28 eV和724.78 eV处的峰分属于Fe2+，而717.38 eV和733.4 eV两个峰分别对应于卫星峰[26]；Fe/C复合材料的O1s光谱如图3(e)所示，在529.58、530.48、531.38和531.98 eV周围有4个不同的峰，分别归属于Fe3O4、C=O、C—O和FeCO3[28]。
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图 3 Fe/C复合材料的XPS全谱 (a)、Cls (b)、N1s (c)、Fe2p (d)、O1s (e)Figure 3. Fe/C composite XPS full spectum (a), Cls (b), N1s (c), Fe2p (d), O1s (e)2.2 电磁参数分析
Fe/C复合材料的微波吸收特性通过矢量网络分析仪(VNA)在2~18 GHz的频率范围内测量，样品填料量为30wt%，电磁参数包括介电常数ε( ε = ε'−jε'') 和磁导率μ(μ= μ'− jμ'')，其中介电常数实部(ε')和磁导率实部(μ′)代表电能和磁能的储存能力，相应的虚部( ε''、μ'')代表电能和磁能的损耗能力。如图4(a)所示，Fe/C复合材料在介电常数实部(ε')和介电常数虚部(ε'')变化上均有频散效应发生，Fe/C-700、 Fe/C-800和 Fe/C-900分别从8.52、10.5、12.64降至5.91、7.96和7.6[29]，介电常数实部(ε')的明显下降可能是由于碳基复合材料中频率相关的介电色散引起的；介电常数虚部随频率变化曲线如图4(b)所示，其变化趋势同实部相反，在2至18 GHz的频率范围3个样品介电常数虚部值都有所增加，Fe/C-700、 Fe/C-800和 Fe/C-900分别从1.89、2.74、5.15增至2.96、4.3和5.65，介电常数虚部的增加原因有两种：一种是归因于碳组分相对含量和相对石墨化程度的提升、另一种是由于随着煅烧温度的提高，单个的Fe原子被杂原子取代引起的电偶极子的增加，介电常数虚部的提升也增强了复合材料的介电损耗能力；复合材料的介电常数实部和虚部在6至18 GHz频率范围内出现多重共振现象, 这种波动峰可能是由材料内部多种损耗机制导致的。
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图 4 Fe/C复合材料的介电常数实部ε' (a)、介电常数虚部ε'' (b)、介电损耗正切值tanδϵ(c)、复磁导率实部μ' (d)、复磁导率虚部μ'' (e)、复磁损耗正切值tanδμ(f)、Cole-Cole环 (g)、涡流损耗对磁损耗的贡献(C0) (h)、衰减因子谱 (i)Figure 4. Fe/C composite real part of the dielectric constant ε' (a), Imaginary part of the dielectric constant ε'' (b), Dielectric loss tanδε (c), Complex magnetic permeability real part μ' (d), Complex magnetic permeability imaginary part μ'' (e), Complex magnetic loss tanδμ (f), Cole-Cole (g), Contribution of Eddy current loss to magnetic loss (C0) (h) and Attenuation factor mapping (i)介电损耗角正切值(tanδε=ε″) 可用于表征材料的介电损耗的强弱。如图4(c)所示。Fe/C-700、Fe/C-800、Fe/C-900在低频(2~8 GHz)和高频(10~18 GHz)都出现多重共振峰，表明存在多重极化弛豫过程，通常，高频共振峰归因于界面极化，低频共振峰归因为偶极极化；从图中可以出在高频段(17 GHz)时，介电损耗正切值显著增强，其中Fe/C-800、Fe/C-900增强幅度尤为突出，由此推断，煅烧温度的提高有利于促进复合材料Fe原子和石墨碳构建导电网络，增强了材料的极化行为和介电损耗能力；Fe/C-900具有最佳的介电损耗能力，是由于它具有较高的介电正切值。
众所周知，磁损耗特性能够显著的提升材料的电磁波损耗性能。图4(d)~4(e)是Fe/C复合材料相对复磁导率的实部和虚部随频率变化曲线，结合电磁参数变化可进一步探究复合材料的吸波性能。Fe/C-700、Fe/C-800、Fe/C-900分别从1.33、1.28、1.17降至1.06、1.03、1.032。实部曲线的变化趋势相似；Fe/C复合材料复磁导率虚部(μ'')如图4(e)所示，Fe/C-700、Fe/C-800、Fe/C-900在低频区(2~8 GHz)和高频区(12~18 GHz)有清晰的共振峰，根据文献记载，低频共振峰与自然共振相关，高频共振峰与交换共振相关；3个样品的虚部随着频率的增加虚部值呈下降趋势，值得注意的是μ''在高频下呈现负值。根据麦克斯韦方程，交变电场可以产生反向磁场，如果感应磁场比原始磁场强，磁能可以直接辐射出去，从而产生负磁导率。
磁损耗角的正切值( \mathrm{tan}{\delta }_{\mu }={\mu'' }/{\mu' } )可用于表征材料的磁损耗能力的强弱。如图4(f)所示，Fe/C-700、Fe/C-800曲线的变化趋势相似，随着频率的增加Fe/C-900正切值略低于另外两个样品曲线，根据TG测试结果可知Fe/C-900的磁性成分(Fe)较低，是导致磁损耗角正切值低的原因，其中复合材料介电损耗正切值远高于磁损耗正切值，这表明介电损耗比磁损耗对电磁波吸收的贡献更大。
为了进一步探究磁损耗机制，由下式计算出Fe/C复合材料的C0值：
{C_0}{\text{ = }}\frac{{\mu ''}}{{{{(\mu ')}^2}f}} (2) 对于生物质衍生碳基复合材料电磁波损耗机制主要是介电损耗，而介电损耗机制主要由极化弛豫解释，因此引入Cole-Cole半圆模型来解释复合材料极化弛豫过程。ε'和ε''之间的关系如下式：
\left(\varepsilon ' - \frac{{{{({\varepsilon _s} + {\varepsilon _\infty })}^2}}}{2}\right) + \varepsilon '{'^2} = \left(\frac{{{{({\varepsilon _s} - {\varepsilon _\infty })}^2}}}{2}\right) (3) 式中：f代表电磁波频率；εs、ε∞分别为静态介电常数、高频极限相对介电常数。 图4(g)所示，Fe/C-700存在3个Cole-Cole半圆环，表明其存在3个极化弛豫过程，Fe/C-800、 Fe/C-900分别存在四个和五个极化弛豫过程[30]，表明煅烧温度的提高有利于材料的极化能力；Fe/C-700、Fe/C-800和 Fe/C-900有部分扭曲的半圆，这表明除了极化弛豫以外，还存在其他的损耗机制；并且Fe/C-800、 Fe/C-900 Cole-Cole曲线在低频下其尾部变得长而直，根据以往研究表明，复合材料中存在另一种电磁波衰减机制——电导损耗，造成这种损耗的主要原因是由于高温碳化后的材料中存在金属Fe和石墨碳，提高自由电子的流动，从而增加了材料的电导损耗。
磁损耗机制在整个测试频率域中主要由的自然共振、涡流损耗和交换共振，如图4(h)所示，Fe/C-700、Fe/C-800、Fe/C-900的C0值在2~9 GHz的频率范围内剧烈波动，这表明在该频率范围内磁损耗的主要机制归因于自然共振，材料的几何结构是造成自然共振的主要原因；复合材料C0值在14~18 GHz高频区内也产生轻微的波动，这表明在该频率范围内磁损耗的主要机制归因于交换共振，交换共振主要存在于铁磁材料中[5]。
一般来说，根据广义传输线理论，可以使用下式计算RL值以评估样品的吸收性能。
R_{\rm{L}} = 20\lg \left| {\frac{{{Z_{{\rm{in}}}} - {Z_0}}}{{{Z_{{\rm{in}}}} + {Z_0}}}} \right| (4) {Z_0} = \sqrt {\frac{{{\mu _0}}}{{{\varepsilon _0}}}} (5) {Z_{{\rm{in}}}} = {Z_0}\sqrt {\frac{{{\mu _{\rm{r}}}}}{{{\varepsilon _{\rm{r}}}}}} \tan h\left[ {j\frac{{2{\text{π}} fd}}{c}\sqrt {{\mu _{\rm{r}}}{\varepsilon _{\rm{r}}}} } \right] (6) 式中：μ0、ε0和Z0代表自由空间磁导率、介电常数和输入阻抗；Zin代表材料的输入阻抗；d代表材料的厚度；c代表空间光速；f代表电磁波频率；RL为反射损耗(dB)；εr和μr代表相对介电常数和相对磁导率。通常，当RL值小于−10 dB时，意味着90%的电磁波可以转换，相应的频率范围被定义为有效吸收带宽。材复合材料的复合材料经700℃煅烧，厚度为2 mm时，最大有效吸收带宽为4.05 GHz (12.8~18 GHz)，最大反射损耗值在15 GHz处为−20.5 dB，在吸收剂厚度为2 ~ 5 mm 范围内时，有效吸收频带可达13.52 GHz，如图5(a)所示；Fe/C-800在材料的厚度为2 mm时，材料的有效吸收带宽可达3.7 GHz (10.8~14.5 GHz)，最大反射损耗在为−23.4 dB如图5(b)所示；Fe/C-900有效吸收频带随着材料的厚度增加逐步向低频移动[6]，这种现象可以用四分之一波长匹配模型解释：
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图 5 Fe/C-700 (a)、Fe/C-800 (b)、Fe/C-900 (c) 的二维反射损耗图；Fe/C-700 (d)、Fe/C-800 (e)、Fe/C-900 (f) 的三维反射损耗图；Fe/C-700 (g)、Fe/C-800 (h)、Fe/C-900 (i) 的阻抗匹配图Figure 5. 2D reflection loss diagrams for Fe/C-700 (a), Fe/C-800 (b), Fe/C-900 (c); 3D reflection loss diagrams for Fe/C-700 (d), Fe/C-800 (e), Fe/C-900 (f); Impedance matching diagram for Fe/C-700 (g), Fe/C-800 (h), Fe/C-900 (i){{{t}}_{\text{m}}}{\text{ = }}\frac{{nc}}{{\left( {4{f_m}\sqrt {\left| {{\varepsilon _r}} \right|} \left| {{\mu _{_r}}} \right|} \right)}}\left( {n{\text{ = }}1,3,5, \cdots } \right) (7) 式中：tm是实现RLmin时的匹配厚度；ƒm是相应的频率，材料的厚度为5 mm时，最大反射损耗值在4.4 GHz处为−35 dB，可以看出样品的最大反射损耗对应频率与其厚度密不可分，并且表现出随着吸收样品厚度的增加，被吸收层中电磁波膜覆盖样品的时间更长，这意味着电磁波更多的被吸收，就会降低其最大反射损耗对应频率。另外，被吸收样品也构成了一个具有折射和反射作用的电磁绝缘体，当电磁波穿过时，会发生折射和反射的现象，反射损耗将会降低。如图5(c)所示，复合材料更好的有效吸收带宽和较低反射损耗值得益于Fe和C形成的导电网络，使其拥有加优异介电特性和磁损耗，因此表现出良好的吸波性能。
材料吸波性能的差异受衰减因子和阻抗匹配的影响,衰减因子用于评价材料电磁衰减能力，阻抗匹配用于评价电磁波是否可最大限度进入材料内部，且阻抗匹配是完成电磁波衰减的前提。图4(i)为Fe/C复合材料的衰减因子曲线。可以看出，随着频率增加，复合材料的衰减能力逐渐增强，材料在中高频区域的衰减性能最优。Fe/C-700衰减能力最弱，这主要是其相对较低的介电常数所致。众所周知，衰减因子和阻抗匹配共同决定材料的吸波性能差异，图5(g)为 Fe/C复合材料700℃、800℃和900℃的阻抗匹配因子随频率变化图，研究可知|∆| 值的大小影响着阻抗匹配的性能。计算|Δ|如下式：
\left| \varDelta \right|{\text{ = }}\left| {{{\sin h }^2}(Kfd) - M} \right| (8) 式中，K为常数：
K = \frac{{4{\text{π}} \sqrt {\mu _{\rm{r}}'\varepsilon _{\rm{r}}'} \sin\dfrac{{{\delta _{\rm{e}}}{\text{ + }}{\delta _{\rm{m}}}}}{2}}}{{{{c}} {\text{cos}}{\delta _{\rm{e}}}{\text{cos}}{\delta _{\rm{m}}}}} (9) 阻抗匹配因子(|Δ|)接近0.4的区域面积越大，阻抗匹配特性越好。利用公式(9)计算出Fe/C-700、Fe/C-800、Fe/C-900阻抗匹配有效区域占比为23.7%、36.2%和60.3%。对比可知，Fe/C-700表明其与电磁波最不相容，导致电磁波在材料表面发生反射或散射，无法有效吸收电磁波，而Fe/C-900 电磁波与复合材料的兼容性最好，减少电磁波在材料表面发生反射而吸波性能遭受损失，具有适宜的衰减特性和良好的阻抗匹配，吸波性能最佳。
为了更好地理解复合材料的电磁波吸收方式，图6总结了Fe/C复合材料电磁波吸收机制。首先生物质衍生碳和Fe纳米颗粒的协同效应在优化阻抗匹配特性和提高电磁波的衰减能力起着至关重要的作用，其次，样品分散在石蜡中以形成电导网络，更多的电子在不同的碳层之间跳跃，网络导电性增强，将更多的电磁波能量转化为热能，体心立方Fe和碳管之间形成大量的异质界面，并且异质界面之间Fe纳米颗粒和碳层有利于在交变电磁场下的自由电荷积累和振荡，从而增强了界面极化；此外，在复合材料中形成了高密度的氮杂取代，可以极大地促进偶极极化，进一步提高了介电损耗能力，Fe纳米颗粒贡献的磁滞损耗和在低频段发生的自然铁磁共振以及在高频的交换铁磁共振和伴随的涡流损耗，都增强了复合材料的磁损耗性能，多种损耗机制有益于复合材料吸波性能的提升。
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图 6 Fe/C复合材料吸波机制图Figure 6. Diagram of the wave absorption mechanism of Fe/C composites3. 结 论
综上所述，以香蒲为载体，Fe3+为金属源，经原位吸附、碳热还原得到Fe/C复合材料。
(1) X射线衍射测试结果表明，复合材料经高温煅烧后，生物质香蒲转化为碳基质，铁盐转化为Fe纳米颗粒，且随温度升高Fe纳米颗粒结晶性增强。
(2) 反射损耗结果显示，900℃的Fe/C复合材料的吸波性能最佳，厚度为5 mm时，最大反射损耗达−35 dB，复合材料优异的吸波性能取决于其较好的阻抗匹配特性和介电损耗与磁损耗的协同作用，研究将为新型生物质衍生轻质、高效、价廉的碳基吸波材料提供实验指导。
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图 2 (a) 流化床化学气相沉积(CVD)工艺制备氮化硼纳米粒子(BNNS)/碳纳米管(CNTs)示意图和三维BNNS/CNTs/环氧树脂(EP)复合材料制备示意图；(b) 三维泡沫骨架上沉积的BNNS/CNTs的SEM图像；(c) 三维导热网络结构对BNNS/CNTs/EP复合材料导热系数的增强作用[39]
Figure 2. (a) Schematic illustration of the fluidized bed chemical vapor deposition (CVD) process for the fabrication of boron nitride nanoparticles (BNNS)/carbon nanotubes (CNTs) and the preparation process of 3D BNNS/CNTs/epoxy (EP) composie; (b) SEM image of BNNS/CNTs deposited on 3D foam skeleton; (c) Enhancement of 3D network structure on thermal conductivity of BNNS/CNTs/EP composite[39]
PU—Polyurethane; CNTs15%—Mass fraction (15wt%) of CNTs in BNNS/CNTs samples
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图 3 (a) 具有连续网络结构的(CNT+BN)@聚偏二氟乙烯(PVDF)复合材料制备示意图；(b) 均匀分散的CNT/BN/PVDF复合材料和具有连续网络结构的(CNT+BN)@PVDF复合材料在不同混杂填料配比下的导热系数的对比； (c) (CNT+BN)@PVDF复合材料在不同热压温度下的导热系数变化，插图显示了混杂填料网络形貌[18]
Figure 3. (a) Schematic representation showing the preparation of interconnected (CNT+BN)@polyvinylidene fluoride (PVDF) composites; (b) Thermal conductivities of uniformly dispersed CNT/BN/PVDF and interconnected (CNT+BN)@PVDF composites as a function of the volume ratio of hybrid fillers; (c) Thermal conductivities of (CNT+BN)@PVDF composites molded at varied compression temperature, the insets exhibited the morphologies of hybrid filler network[18]
TC—Thermal conductivity
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图 4 (a) 热塑性聚氨酯(TPU)/聚多巴胺(PDA)/Ag复合材料制备示意图；(b) TPU/PDA/Ag纤维膜表面 SEM图像；(c) 热流沿面内方向的连续Ag粒子路径的传导示意图；(d) 不同Ag含量下TPU/PDA/Ag复合膜的导热系数[53]
Figure 4. (a) Schematic illustration of the preparation process of thermoplastic polyurethane (TPU)/polydopamine (PDA)/Ag composites; (b) SEM image of the surface of TPU/PDA/Ag fiber membrane; (c) Schematic illustration of heat flow transfer along continuous silver particles pathways in-plane direction; (d) Thermal conductivities of TPU/PDA/Ag composite films versus mass fraction of Ag[53]
TPU/PDA/Ag-x—Mass fraction (xwt%) of Ag loading in TPU/PDA/Ag (polyurethane/polydopamine/argentum) composite films
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图 5 (a) 通过胶乳共混-铸膜工艺制备具有连续网络的天然橡胶(NR)-羧基化多壁碳纳米管(MWCNTR)复合材料的制备示意图；(b) NR-MWCNTR复合材料的TEM图像[56]
Figure 5. (a) Schematic representation of the preparation of natural rubber (NR)-carboxylated multi-walled carbon nanotubes (MWCNTR) composites with interconnected network by latex blending-solution casting process; (b) TEM images of NR-MWCNTR composite film[56]
MWCNT—Multi-walled carbon nanotube
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图 6 聚合物和导热填料(包括金属填料、碳基填料和陶瓷填料)的导热系数[10]
Figure 6. Thermal conductivity of common materials including polymers and fillers (Metals, ceramics and carbon materials)[10]
BNNT—Boron nitride nanotube; h-BN—Hexagonal boron nitride; BAs—Cubic boron arsenide; AlN—Aluminum nitride; BNNS—Boron nitride nanosheet
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图 7 (a) Cu@TPU复合材料制备和Cu2+在TPU颗粒表面还原的示意图[71]；(b) PVDF@PDA@Ag/低熔点合金(LMPA)、PVDF/LMPA和PVDF@PDA/LMPA复合材料制备示意图[74]
Figure 7. (a) Schematic illustration of preparation process of Cu@TPU composites and Cu2+ reduction process on TPU granules[71]; (b) Schematic diagram of fabrication process of PVDF@PDA@Ag/low melting point alloy (LMPA), PVDF/LMPA and PVDF@PDA/LMPA composites[74]
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图 8 (a) BN@聚苯硫醚(PPS)和BN/PPS复合材料的制备示意图；(b) 30vol%BN含量下BN@PPS颗粒的OM图像；(c) 具有连续网络结构的BN/PPS复合材料和PPS/BN共混复合材料的导热系数[85]
Figure 8. (a) Schematic illustrating the synthesis process of BN@polyphenylene sulfide (PPS) and BN/PPS composite; (b) OM image of BN@PPS particles with 30vol%BN loading; (c) Thermal conductivity of the interconnected architecture BN/PPS composites and PPS/BN blend composites[85]
APTES—3-aminopropyltriethoxysilane; S-PPS—Segregated polyphenylene sulfide; A-BN—APTES functionalized BN; PEI—Polyethylenimine
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图 9 (a) 具有连续网络结构的还原氧化石墨烯(RGO)/TPU复合材料的制备过程示意图；(b) RGO/TPU复合材料切片的OM图像；(c) 连续网络结构RGO/TPU的导热系数[20]
Figure 9. (a) Schematic illustration of fabrication process of reduced graphene oxide (RGO)/TPU composite with interconnected structure; (b) Optical microscope images of RGO/TPU composite sections; (c) Thermal conductivities of RGO/TPU with interconnected structure[20]
GO—Graphene oxide
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图 10 (a) 具有三维连续网络结构的聚苯乙烯(PS)/氧化石墨烯(GO)-PDA复合材料制备示意图，插图为PS/GO-PDA薄膜照片；((b), (b’)) PS/GO-PDA微球的SEM图像；(c) 不同填料含量下PS/GO-PDA复合材料的面内和面外导热系数；(d) 不同填料含量下PS/GO和PS/GO-PDA体积电阻率[103]
Figure 10. (a) Schematic illustration of preparation of the polystyrene (PS)/graphene oxide (GO)-PDA composites with a continuous three-dimensional network. Inset: photograph of the PS/GO-PDA thin film; ((b), (b’)) SEM images of the PS/GO-PDA microspheres; (c) In-plane and through-plane thermal conductivities of the PS/GO-PDA composites with different filler loadings; (d) Volume electrical resistivity of the PS/GO and PS/GO-PDA with different filler loadings[103]
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[1] DOAN V C, VU M C, THIEU N A T, et al. Copper flake-coated cellulose scaffold to construct segregated network for enhancing thermal conductivity of epoxy composites[J]. Composites Part B: Engineering,2019,165:772-778. DOI: 10.1016/j.compositesb.2019.02.015
[2] GUO Y Q, YANG X T, RUAN K P, et al. Reduced graphene oxide heterostructured silver nanoparticles significantly enhanced thermal conductivities in hot-pressed electrospun polyimide nanocomposites[J]. ACS Applied Materials & Interfaces,2019,11(28):25465-25473.
[3] AL-AHMED A, MAZUMDER M A J, SALHI B, et al. Effects of carbon-based fillers on thermal properties of fatty acids and their eutectics as phase change materials used for thermal energy storage: A Review[J]. Journal of Energy Storage,2021,35:102329. DOI: 10.1016/j.est.2021.102329
[4] ARBOLEDA-CLEMENTE L, GARCÍA-FONTE X, ABAD M J, et al. Role of rheology in tunning thermal conductivity of polyamide 12/polyamide 6 composites with a segregated multiwalled carbon nanotube network[J]. Journal of Composite Materials,2018,52(18):2549-2557. DOI: 10.1177/0021998317749715
[5] 石嵩, 张传琪, 张达, 等. 碳纳米管填充聚合物基导热复合材料的研究进展[J]. 科学通报, 2022, 67(30):3531-3545. DOI: 10.1360/TB-2022-0318 SHI Song, ZHANG Chuanqi, ZHANG Da, et al. Progress on carbon nanotube filled polymer-based thermal conductive composites[J]. Chinese Science Bulletin,2022,67(30):3531-3545(in Chinese). DOI: 10.1360/TB-2022-0318
[6] MENG X G, YU H J, WANG L, et al. Recent progress on fabrication and performance of polymer composites with highly thermal conductivity[J]. Macromolecular Materials and Engineering,2021,306(11):2100434. DOI: 10.1002/mame.202100434
[7] 王世民, 温变英. 模压氮化硼/聚对苯二甲酸乙二醇酯复合材料的导热机制与散热效果[J]. 复合材料学报, 2023, 40(1):160-170. DOI: 10.13801/j.cnki.fhclxb.20211215.002 WANG Shimin, WEN Bianying. Thermal conduction mechanism and heat dissipation effect of compression molded boron nitride/polyethylene terephthalate composites[J]. Acta Materiae Compositae Sinica,2023,40(1):160-170(in Chinese). DOI: 10.13801/j.cnki.fhclxb.20211215.002
[8] WU W T, ZHENG M S, LU K J, et al. Thermally conductive composites based on hexagonal boron nitride nanosheets for thermal management: Fundamentals to applications[J]. Composites Part A: Applied Science and Manufacturing,2023,169:107533. DOI: 10.1016/j.compositesa.2023.107533
[9] LI J P, CHENG R, CHENG Z, et al. Silver-nanoparticle-embedded hybrid nanopaper with significant thermal conductivity enhancement[J]. ACS Applied Materials & Interfaces,2021,13(30):36171-36181.
[10] HE X H, WANG Y C. Recent advances in the rational design of thermal conductive polymer composites[J]. Industrial & Engineering Chemistry Research,2021,60(3):1137-1154.
[11] WANG Y, WU W, DRUMMER D, et al. Improvement of thermal conductivity and mechanical properties for polybenzoxazine composites via incorporation of epoxy resin and segregated structure[J]. Materials Research Express,2020,7(9):095301. DOI: 10.1088/2053-1591/abb263
[12] LIU R P, HAN H, WU X T, et al. Construction of “core-shell” structure for improved thermal conductivity and mechanical properties of polyamide 6 composites[J]. Polymer Bulletin,2021,78(5):2791-2803. DOI: 10.1007/s00289-020-03242-z
[13] LI Z L, KONG J J, JU D D, et al. Thermal conductivity enhancement of poly(3-hydroxylbutyrate) composites by constructing segregated structure with the aid of poly(ethylene oxide)[J]. Composites Science and Technology,2017,149:185-191. DOI: 10.1016/j.compscitech.2017.06.028
[14] 林夏泽, 温变英. 界面效应对功能复合材料热传导行为的影响[J]. 复合材料学报, 2022, 39(4):1498-1510. DOI: 10.13801/j.cnki.fhclxb.20211009.002 LIN Xiaze, WEN Bianying. Influence of interfacial effect on heat conduction behavior of functional composites[J]. Acta Materiae Compositae Sinica,2022,39(4):1498-1510(in Chinese). DOI: 10.13801/j.cnki.fhclxb.20211009.002
[15] BURGER N, LAACHACHI A, FERRIOL M, et al. Review of thermal conductivity in composites: Mechanisms, parameters and theory[J]. Progress in Polymer Science,2016,61:1-28. DOI: 10.1016/j.progpolymsci.2016.05.001
[16] LIU B C, LI Y B, FEI T, et al. Highly thermally conductive polystyrene/polypropylene/boron nitride composites with 3D segregated structure prepared by solution-mixing and hot-pressing method[J]. Chemical Engineering Journal,2020,385:123829. DOI: 10.1016/j.cej.2019.123829
[17] ZHAO F W, ZHANG G F, ZHAO S, et al. Fabrication of pristine graphene-based conductive polystyrene compo-sites towards high performance and light-weight[J]. Composites Science and Technology,2018,159:232-239. DOI: 10.1016/j.compscitech.2018.02.013
[18] WANG Z G, HUANG Y F, ZHANG G Q, et al. Enhanced thermal conductivity of segregated poly (vinylidene fluoride) composites via forming hybrid conductive network of boron nitride and carbon nanotubes[J]. Industrial & Engineering Chemistry Research,2018,57(31):10391-10397.
[19] HU S F, XU B F, ZHAO Y, et al. Preparation of CNTs/PP@Gr composites with a segregated structure and enhanced electrical and thermal conductive properties by the Pickering emulsion method[J]. Composites Science and Technology,2022,222:109374.
[20] LI A, ZHANG C, ZHANG Y F. RGO/TPU composite with a segregated structure as thermal interface material[J]. Composites Part A: Applied Science and Manufacturing,2017,101:108-114. DOI: 10.1016/j.compositesa.2017.06.009
[21] HAN Z D, FINA A. Thermal conductivity of carbon nano-tubes and their polymer nanocomposites: A review[J]. Progress in Polymer Science,2011,36(7):914-944. DOI: 10.1016/j.progpolymsci.2010.11.004
[22] CHEN H Y, GINZBURG V V, YANG J, et al. Thermal conductivity of polymer-based composites: Fundamentals and applications[J]. Progress in Polymer Science,2016,59:41-85. DOI: 10.1016/j.progpolymsci.2016.03.001
[23] HUANG Y, ELLINGFORD C, BOWEN C, et al. Tailoring the electrical and thermal conductivity of multi-component and multi-phase polymer composites[J]. International Materials Reviews,2020,65(3):129-163. DOI: 10.1080/09506608.2019.1582180
[24] PIETRAK K, WIŚNIEWSKI T S. A review of models for effective thermal conductivity of composite materials[J]. Journal of Power Technologies,2014,95(1):14-24.
[25] CALLAWAY J. Model for lattice thermal conductivity at low temperatures[J]. Physical Review,1959,113(4):1046-1051. DOI: 10.1103/PhysRev.113.1046
[26] ZHOU W X, CHENG Y A, CHEN K Q, et al. Thermal conductivity of amorphous materials[J]. Advanced Functional Materials,2020,30(8):1903829. DOI: 10.1002/adfm.201903829
[27] GUO Y Q, RUAN K P, SHI X T, et al. Factors affecting thermal conductivities of the polymers and polymer composites: A review[J]. Composites Science and Technology,2020,193:108134. DOI: 10.1016/j.compscitech.2020.108134
[28] YANG X T, LIANG C B, MA T B, et al. A review on thermally conductive polymeric composites: Classification, measurement, model and equations, mechanism and fabrication methods[J]. Advanced Composites and Hybrid Materials,2018,1(2):207-230. DOI: 10.1007/s42114-018-0031-8
[29] OLUWALOWO A, NGUYEN N, ZHANG S L, et al. Electrical and thermal conductivity improvement of carbon nano-tube and silver composites[J]. Carbon,2019,146:224-231. DOI: 10.1016/j.carbon.2019.01.073
[30] KARGAR F, BARANI Z, SALGADO R, et al. Thermal percolation threshold and thermal properties of composites with high loading of graphene and boron nitride fillers[J]. ACS Applied Materials & Interfaces,2018,10(43):37555-37565.
[31] WU Z H, XU C A, MA C Q, et al. Synergistic effect of aligned graphene nanosheets in graphene foam for high-performance thermally conductive composites[J]. Advanced Materials,2019,31(19):1900199. DOI: 10.1002/adma.201900199
[32] RYU S H, CHO H B, KWON Y T, et al. Quasi-isotropic thermal conduction in percolation networks: Using the pore-filling effect to enhance thermal conductivity in polymer nanocomposites[J]. ACS Applied Polymer Materials,2020,3(3):1293-1305.
[33] YANG J, SHEN X, YANG W, et al. Templating strategies for 3D-structured thermally conductive composites: Recent advances and thermal energy applications[J]. Progress in Materials Science,2023,133:101054.
[34] HAN L Y, LI K Z, FU Y Q, et al. Multifunctional electromagnetic interference shielding 3D reduced graphene oxide/vertical edge-rich graphene/epoxy nanocompo-sites with remarkable thermal management performance[J]. Composites Science and Technology,2022,222:109407. DOI: 10.1016/j.compscitech.2022.109407
[35] TAN X, YUAN Q L, QIU M T, et al. Rational design of graphene/polymer composites with excellent electromagnetic interference shielding effectiveness and high thermal conductivity: A mini review[J]. Journal of Materials Science & Technology,2022,117:238-250.
[36] ANAND S, VU M C, MANI D, et al. Dual 3D networks of graphene derivatives based polydimethylsiloxane composites for electrical insulating electronic packaging materials with outstanding electromagnetic interference shielding and thermal dissipation performances[J]. Chemical Engineering Journal, 2023, 462: 142017.
[37] BA K X, ZHANG M Y, WANG X D, et al. Porous graphene composites fabricated by template method used for electromagnetic shielding and thermal conduction[J]. Diamond and Related Materials,2023,131:109585. DOI: 10.1016/j.diamond.2022.109585
[38] YE L J, CHEN C M, BIAN Y X, et al. Segregated structures induced linear mechanoelectrical responses to low strains for elastomer/CNTs composites[J]. Composites Science and Technology,2022,230:109752. DOI: 10.1016/j.compscitech.2022.109752
[39] YANG W, WANG Y F, LI Y, et al. Three-dimensional skeleton assembled by carbon nanotubes/boron nitride as filler in epoxy for thermal management materials with high thermal conductivity and electrical insulation[J]. Composites Part B: Engineering,2021,224:109168. DOI: 10.1016/j.compositesb.2021.109168
[40] KIM J, HAN N M, KIM J, et al. Highly conductive and fracture-resistant epoxy composite based on non-oxidized graphene flake aerogel[J]. ACS Applied Materials & Interfaces,2018,10(43):37507-37516.
[41] BUSTILLOS J, ZHANG C, BOESL B, et al. Three-dimensional graphene foam-polymer composite with superior deicing efficiency and strength[J]. ACS Applied Materials & Interfaces,2018,10(5):5022-5029.
[42] LI X H, LIU P F, LI X F, et al. Vertically aligned, ultralight and highly compressive all-graphitized graphene aerogels for highly thermally conductive polymer composites[J]. Carbon,2018,140:624-633. DOI: 10.1016/j.carbon.2018.09.016
[43] LEE W, HONG J, SONG J, et al. Fabrication of high-performance thermally conductive phase change material composites with porous ceramic filler network for efficient thermal management[J]. Composites Science and Technology,2023,240:110092. DOI: 10.1016/j.compscitech.2023.110092
[44] HU H L, ZHANG G, XIAO L G, et al. Preparation and electrical conductivity of graphene/ultrahigh molecular weight polyethylene composites with a segregated structure[J]. Carbon,2012,50(12):4596-4599. DOI: 10.1016/j.carbon.2012.05.045
[45] DU J H, ZHAO L, ZENG Y, et al. Comparison of electrical properties between multi-walled carbon nanotube and graphene nanosheet/high density polyethylene compo-sites with a segregated network structure[J]. Carbon,2011,49(4):1094-1100. DOI: 10.1016/j.carbon.2010.11.013
[46] LI M K, GAO C X, HU H L, et al. Electrical conductivity of thermally reduced graphene oxide/polymer composites with a segregated structure[J]. Carbon,2013,65:371-373. DOI: 10.1016/j.carbon.2013.08.016
[47] GAO C, ZHANG S M, WANG F, et al. Conductive compo-sites with segregated structure and ultralow percolation threshold via flocculation-assembled PVDF/graphene core-shell particles[J]. Materials Letters,2015,158:428-431. DOI: 10.1016/j.matlet.2015.06.011
[48] WANG L, WANG H, LI B, et al. Highly electrically conductive polymer composite with a novel fiber-based segregated structure[J]. Journal of Materials Science,2020,55(25):11727-11738. DOI: 10.1007/s10853-020-04797-y
[49] XU M K, LIU J, ZHANG H B, et al. Electrically conductive Ti3C2Tx MXene/polypropylene nanocomposites with an ultralow percolation threshold for efficient electromagnetic interference shielding[J]. Industrial & Engi-neering Chemistry Research,2021,60(11):4342-4350.
[50] CHANG C G, YANG J C, ZHANG G, et al. Fabrication of segregated poly(arylene sulfide sulfone)/graphene nanoplate composites reinforced by polymer fibers for electromagnetic interference shielding[J]. Nano Materials Science,2022,4(3):285-293. DOI: 10.1016/j.nanoms.2021.11.001
[51] ZHAO G J, CAO X Y, ZHANG Q, et al. A novel interpenetrating segregated functional filler network structure for ultra-high electrical conductivity and efficient EMI shielding in CPCs containing carbon nanotubes[J]. Materials Today Physics,2021,21:100483. DOI: 10.1016/j.mtphys.2021.100483
[52] LI X, LI C H, ZHANG X M, et al. Simultaneously enhanced thermal conductivity and mechanical properties of PP/BN composites via constructing reinforced segregated structure with a trace amount of BN wrapped PP fiber[J]. Chemical Engineering Journal,2020,390:124563. DOI: 10.1016/j.cej.2020.124563
[53] YANG G, WANG M J, DONG J W, et al. Fibers-induced segregated-like structure for polymer composites achieving excellent thermal conductivity and electromagnetic interference shielding efficiency[J]. Composites Part B: Engi-neering,2022,246:110253. DOI: 10.1016/j.compositesb.2022.110253
[54] WANG L Y, ZHANG J T, SUN Y Y, et al. Green preparation and enhanced gas barrier property of rubber nanocomposite film based on graphene oxide-induced chemical crosslinking[J]. Polymer,2021,225:123756. DOI: 10.1016/j.polymer.2021.123756
[55] ZHAN Y H, MENG Y Y, LI Y C. Electric heating behavior of flexible graphene/natural rubber conductor with self-healing conductive network[J]. Materials Letters,2017,192:115-118. DOI: 10.1016/j.matlet.2016.12.045
[56] GEORGE N, CHANDRA J, MATHIAZHAGAN A, et al. High performance natural rubber composites with conductive segregated network of multiwalled carbon nanotubes[J]. Composites Science and Technology,2015,116:33-40. DOI: 10.1016/j.compscitech.2015.05.008
[57] ZHU Y, WEI L Y, FU X, et al. Super strong and tough elastomers enabled by sacrificial segregated network[J]. Chinese Journal of Polymer Science,2021,39(3):377-386. DOI: 10.1007/s10118-020-2484-9
[58] QIN H M, DENG C R, LU S J, et al. Enhanced mechanical property, thermal and electrical conductivity of natural rubber/graphene nanosheets nanocomposites[J]. Polymer Composites,2020,41(4):1299-1309. DOI: 10.1002/pc.25455
[59] LI Y J, HE Q, ZHANG H, et al. Functionalised graphene oxide-bromobutyl rubber composites with segregated structure for enhanced gas barrier properties[J]. Plastics, Rubber and Composites,2022,51(7):363-371. DOI: 10.1080/14658011.2021.2008702
[60] BOURGEAT-LAMI E, FAUCHEU J, NOËL A. Latex routes to graphene-based nanocomposites[J]. Polymer Che-mistry,2015,6(30):5323-5357. DOI: 10.1039/C5PY00490J
[61] SCHERILLO G, LAVORGNA M, BUONOCORE G G, et al. Tailoring assembly of reduced graphene oxide nanosheets to control gas barrier properties of natural rubber nanocomposites[J]. ACS Applied Materials & Interfaces,2014,6(4):2230-2234.
[62] HAN L J, WANG H R, TANG Q, et al. Preparation of graphene/polypropylene composites with high dielectric constant and low dielectric loss via constructing a segregated graphene network[J]. RSC Advances,2021,11(60):38264-38272. DOI: 10.1039/D1RA06138K
[63] GEORGE N, VARGHESE G A, JOSEPH R. Improved mechanical and barrier properties of Natural rubber-Multiwalled carbon nanotube composites with segregated network structure[J]. Materials Today: Proceedings,2019,9:13-20. DOI: 10.1016/j.matpr.2019.02.030
[64] CUI J S, ZHOU S X. Facile fabrication of highly conductive polystyrene/nanocarbon composites with robust interconnected network via electrostatic attraction strategy[J]. Journal of Materials Chemistry C,2018,6(3):550-557. DOI: 10.1039/C7TC04752E
[65] XU C H, WU W C, ZHENG Z J, et al. Strengthened, conductivity-tunable, and low solvent-sensitive flexible conductive rubber films with a Zn2+-crosslinked one-body segregated network[J]. Composites Science and Technology,2021,203:108606. DOI: 10.1016/j.compscitech.2020.108606
[66] SONG Q C, CHEN B X, ZHOU Z H, et al. Flexible, stretchable and magnetic Fe3O4@Ti3C2Tx/elastomer with supramolecular interfacial crosslinking for enhancing mechanical and electromagnetic interference shielding performance[J]. Science China Materials,2021,64(6):1437-1448. DOI: 10.1007/s40843-020-1539-2
[67] WU S L, SHI T J, ZHANG L Y. Latex co-coagulation approach to fabrication of polyurethane/graphene nanocomposites with improved electrical conductivity, thermal conductivity, and barrier property[J]. Journal of Applied Polymer Science,2016,133(11):43117.
[68] LI M N, TANG C, ZHANG L, et al. A thermally conductive epoxy polymer composites with hybrid fillers of copper nanowires and reduced graphene oxide[J]. Journal of Materials Science: Materials in Electronics,2017,28(20):15694-15700. DOI: 10.1007/s10854-017-7459-4
[69] FENG Y Z, LI X W, ZHAO X Y, et al. Synergetic improvement in thermal conductivity and flame retardancy of epoxy/silver nanowires composites by incorporating “branch-like” flame-retardant functionalized graphene[J]. ACS Applied Materials & Interfaces,2018,10(25):21628-21641.
[70] LIU F, XIE Z X, CAI Y F, et al. Electromagnetic interference shielding property of silver nanowires/polymer foams with low thermal conductivity[J]. Journal of Materials Science: Materials in Electronics,2021,32:28394-28405. DOI: 10.1007/s10854-021-07219-0
[71] WANG Y, CHEN Q M, LIU C, et al. Highly enhanced thermal conductivity of TPU composites with segregated network constructed by the in-situ reduction of copper[J]. Journal of Alloys and Compounds,2023,941:168801. DOI: 10.1016/j.jallcom.2023.168801
[72] ZHANG L, LI Z F, LIU G T, et al. Enhancement of the electrical and thermal conductivity of epoxy-based compo-site films through the construction of the multi-scale conductive bridge structure[J]. Composites Science and Technology,2023,239:110074. DOI: 10.1016/j.compscitech.2023.110074
[73] ZHAN Y H, LAVORGNA M, BUONOCORE G, et al. Enhancing electrical conductivity of rubber composites by constructing interconnected network of self-assembled graphene with latex mixing[J]. Journal of Materials Chemistry,2012,22(21):10464-10468. DOI: 10.1039/c2jm31293j
[74] ZHANG P, ZHANG X, DING X, et al. Improving thermal conductivity of polyvinylidene fluoride/low-melting-point alloy with segregated structure induced by incorporation of silver interface layer[J]. Journal of Polymer Research,2022,29(9):390. DOI: 10.1007/s10965-022-03242-9
[75] BHUTTA M S, TANG X B, AKRAM S, et al. Development of novel hybrid 2D-3D graphene oxide diamond micro composite polyimide films to ameliorate electrical & thermal conduction[J]. Journal of Industrial and Engineering Chemistry,2022,114:108-114. DOI: 10.1016/j.jiec.2022.06.036
[76] 石林, 马忠雷, 景佳瑶, 等. 双导热网络功能化氮化硼纳米片/聚氨酯复合材料的制备与导热性能[J]. 复合材料学报, 2022, 39(10):4531-4539. DOI: 10.13801/j.cnki.fhclxb.20211028.007 SHI Lin, MA Zhonglei, JING Jiayao, et al. Preparation and thermally conductive properties of functionalized boron nitride nanosheets/polyurethane composites with double heat-conduction networks[J]. Acta Materiae Compositae Sinica,2022,39(10):4531-4539(in Chinese). DOI: 10.13801/j.cnki.fhclxb.20211028.007
[77] LEE W, KIM J. Improved thermal conductivity of poly (dimethylsiloxane) composites filled with well-aligned hybrid filler network of boron nitride and graphene oxide[J]. Polymer Testing,2021,104:107402. DOI: 10.1016/j.polymertesting.2021.107402
[78] YOON H, MATTEINI P, HWANG B. Review on three-dimensional ceramic filler networking composites for thermal conductive applications[J]. Journal of Non-Crystalline Solids,2022,576:121272.
[79] HU M C, FENG J Y, NG K M. Thermally conductive PP/AlN composites with a 3D segregated structure[J]. Composites Science and Technology,2015,110:26-34. DOI: 10.1016/j.compscitech.2015.01.019
[80] ZHANG X, XIA X C, YOU H, et al. Design of continuous segregated polypropylene/Al2O3 nanocomposites and impact of controlled Al2O3 distribution on thermal conductivity[J]. Composites Part A: Applied Science and Manufacturing,2020,131:105825. DOI: 10.1016/j.compositesa.2020.105825
[81] LI B, LI R L, XIE Y X. Properties and effect of preparation method of thermally conductive polypropylene/aluminum oxide composite[J]. Journal of Materials Science,2017,52(5):2524-2533. DOI: 10.1007/s10853-016-0546-8
[82] WANG X, LU H, FENG C, et al. Facile method to fabricate highly thermally conductive UHMWPE/BN composites with the segregated structure for thermal management[J]. Plastics, Rubber and Composites,2020,49(5):196-203. DOI: 10.1080/14658011.2020.1726143
[83] DING J W, ZHENG R B, ZHANG Y J, et al. The high thermal conductive and flexible boron nitride/silicone rubber composites with segregated structure[J]. Materials Research Express,2021,8(3):035306. DOI: 10.1088/2053-1591/abed6b
[84] GU J W, GUO Y Q, YANG X T, et al. Synergistic improvement of thermal conductivities of polyphenylene sulfide composites filled with boron nitride hybrid fillers[J]. Composites Part A: Applied Science and Manufacturing,2017,95:267-273. DOI: 10.1016/j.compositesa.2017.01.019
[85] JIANG Y, LIU Y J, MIN P, et al. BN@PPS core-shell structure particles and their 3D segregated architecture composites with high thermal conductivities[J]. Composites Science and Technology,2017,144:63-69. DOI: 10.1016/j.compscitech.2017.03.023
[86] LIU C, WU W, DRUMMER D, et al. Significantly enhanced thermal conductivity of polymer composites via establishing double-percolated expanded graphite/multi-layer graphene hybrid filler network[J]. European Polymer Journal,2021,160:110768. DOI: 10.1016/j.eurpolymj.2021.110768
[87] SUDHINDRA S, KARGAR F, BALANDIN A A. Noncured graphene thermal interface materials for high-power electronics: Minimizing the thermal contact resistance[J]. Nanomaterials,2021,11(7):1699. DOI: 10.3390/nano11071699
[88] LEWIS J S, PERRIER T, BARANI Z, et al. Thermal interface materials with graphene fillers: Review of the state of the art and outlook for future applications[J]. Nanotechnology,2021,32(14):142003. DOI: 10.1088/1361-6528/abc0c6
[89] GAO C W, FENG C P, LU H, et al. Thermally conductive general-purpose polystyrene (GPPS)/graphite composite with a segregated structure: Effect of size of resin and graphite flakes[J]. Polymer-Plastics Technology and Engineering,2018,57(13):1277-1287. DOI: 10.1080/03602559.2017.1381242
[90] LEI Y Z, BAI Y, SHI Y, et al. Composite nanoarchitectonics of poly (vinylidene fluoride)/graphene for thermal and electrical conductivity enhancement via constructing segregated network structure[J]. Journal of Polymer Research,2022,29(5):213. DOI: 10.1007/s10965-022-03052-z
[91] SONG N, CAO D L, LUO X, et al. Highly thermally conductive polypropylene/graphene composites for thermal management[J]. Composites Part A: Applied Science and Manufacturing,2020,135:105912. DOI: 10.1016/j.compositesa.2020.105912
[92] YU J, CHOI H K, KIM H S, et al. Synergistic effect of hybrid graphene nanoplatelet and multi-walled carbon nano-tube fillers on the thermal conductivity of polymer composites and theoretical modeling of the synergistic effect[J]. Composites Part A: Applied Science and Manufacturing,2016,88:79-85. DOI: 10.1016/j.compositesa.2016.05.022
[93] WANG Z G, GONG F, YU W C, et al. Synergetic enhancement of thermal conductivity by constructing hybrid conductive network in the segregated polymer composites[J]. Composites Science and Technology,2018,162:7-13. DOI: 10.1016/j.compscitech.2018.03.016
[94] CHEN R, HE Q X, LI X, et al. Significant enhancement of thermal conductivity in segregated (GnPs&MWCNTs)@polybenzoxazine/(polyether ether ketone)-based composites with excellent electromagnetic shielding[J]. Chemical Engineering Journal,2022,431:134049. DOI: 10.1016/j.cej.2021.134049
[95] ZHANG P, DING X, WANG Y Y, et al. Segregated double network enabled effective electromagnetic shielding composites with extraordinary electrical insulation and thermal conductivity[J]. Composites Part A: Applied Science and Manufacturing,2019,117:56-64. DOI: 10.1016/j.compositesa.2018.11.007
[96] HAO M Y, QIAN X, ZHANG Y G, et al. Thermal conductivity enhancement of carbon fiber/epoxy composites via constructing three-dimensionally aligned hybrid thermal conductive structures on fiber surfaces[J]. Composites Science and Technology,2023,231:109800. DOI: 10.1016/j.compscitech.2022.109800
[97] WU W F, REN T L, LIU X Q, et al. Creating thermal conductive pathways in polymer matrix by directional assembly of synergistic fillers assisted by electric fields[J]. Composites Communications,2022,35:101309. DOI: 10.1016/j.coco.2022.101309
[98] ZHANG H, ZHANG X W, LI D T, et al. Thermal conductivity enhancement via conductive network conversion from “sand-like” to “stone-like” in the polydimethylsiloxane composites[J]. Composites Communications,2020,22:100509. DOI: 10.1016/j.coco.2020.100509
[99] 田恐虎, 吴阳, 盛绍顶, 等. 聚合物基绝缘导热复合材料中碳系填料的研究进展[J]. 复合材料学报, 2021, 38(4):1054-1065. DOI: 10.13801/j.cnki.fhclxb.20201224.001 TIAN Konghu, WU Yang, SHENG Shaoding, et al. Research progress of carbon-based fillers in polymer matrix insulating and thermally conductive composites[J]. Acta Materiae Compositae Sinica,2021,38(4):1054-1065(in Chinese). DOI: 10.13801/j.cnki.fhclxb.20201224.001
[100] LI M N, TANG C, ZHANG L, et al. A thermally conductive and insulating epoxy polymer composite with hybrid filler of modified copper nanowires and graphene oxide[J]. Journal of Materials Science: Materials in Electronics,2018,29(6):4948-4954.
[101] AN D, LI Z W, CHEN H F, et al. Modulation of covalent bonded boron nitride/graphene and three-dimensional networks to achieve highly thermal conductivity for polymer-based thermal interfacial materials[J]. Composites Part A: Applied Science and Manufacturing,2022,156:106890. DOI: 10.1016/j.compositesa.2022.106890
[102] ZHANG X, WU K, LIU Y H, et al. Preparation of highly thermally conductive but electrically insulating compo-sites by constructing a segregated double network in polymer composites[J]. Composites Science and Technology,2019,175:135-142. DOI: 10.1016/j.compscitech.2019.03.017
[103] YUAN H, WANG Y, LI T, et al. Fabrication of thermally conductive and electrically insulating polymer compo-sites with isotropic thermal conductivity by constructing a three-dimensional interconnected network[J]. Nanoscale,2019,11(23):11360-11368. DOI: 10.1039/C9NR02491C
[104] FENG C P, WAN S S, WU W C, et al. Electrically insulating, layer structured SiR/GNPs/BN thermal management materials with enhanced thermal conductivity and breakdown voltage[J]. Composites Science and Technology,2018,167:456-462. DOI: 10.1016/j.compscitech.2018.08.039
-
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其他类型引用(7)
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目的
热界面材料可以有效地将高温电子器件的热量快速传递到热管理元件，以缓解电子器件过热而导致的元件寿命恶化的问题。近年来，由聚合物和高导热填料制成的聚合物基复合材料因其密度低、导热性能可调而受到广泛关注。不同于传统的填料随机分散的复合材料，在聚合物基体中构建三维连续网络结构可以显著增加填料/填料接触、降低导热渗透阈值和界面热阻，显著改善复合材料的导热性能。
方法首先从声子传输的角度，简要分析了聚合物基导热复合材料的导热机制。其次，基于导热填料和聚合物的不同的存在形态，总结了具有连续网络结构的导热复合材料的构筑工艺。总结了不同种类的导热填料对聚合物复合材料的导热性能的影响，主要包括金属填料、陶瓷填料、碳基填料及其混杂填料等。最后，对具有连续网络结构的聚合物基导热复合材料的未来发展前景进行了展望。
结果基于聚合物(颗粒、纤维、乳液、溶液等)和导热填料(微观单独存在或宏观三维连续多孔结构)的不同存在形态，目前已开发出几种在聚合物基体中构建三维互联导热网络的构筑工艺，分别是基于三维多孔泡沫预构筑-聚合物回填或牺牲模板、聚合物颗粒/导热填料的干/湿法沉积-后加工工艺、聚合物纤维/织物沉积-后加工工艺、胶乳混合-铸膜或絮凝工艺等。三维连续导热网络的构筑可为声子提供有效的传播途径，降低声子散射，显著降低导热粒子间的界面接触热阻，进而提高复合材料的热导率。聚合物基导热复合材料中最常采用的导热填料主要包括金属填料、碳基填料、陶瓷填料及其混杂填料等。金属填料通常具有较高的导热系数和电导率，通常应用于对电绝缘性能要求不高的领域。碳基填料具有更加优异的导热系数，对聚合物的导热性能提升更为有效。然而，与金属填料类似，碳基填料优异的导电性限制了其在电子封装领域的应用。陶瓷填料因其优良的导热性和电绝缘性而受到越来越多的关注，多用于制造既导热又电绝缘的复合材料。理想的电子设备热管理材料或热界面材料应同时具有导热系数高、电绝缘性好、热机械稳定性好、成本低等优点。目前，实现聚合物基复合材料的绝缘/导热兼容性能主要有以下两种工艺。一是在填料表面构筑绝缘层，对导热填料进行绝缘化的改性处理，在切断导电传输路径的同时提高界面相互作用，降低界面热阻，主要包括聚合物改性和绝缘陶瓷涂层改性等；二是在微观/宏观等不同尺度上对聚合物的内部结构及填料的分布状态等进行优化设计，在阻断导电网络的同时促进导热网络的形成，主要包括微观尺度上的填料混杂、宏观尺度上的层合结构调控和填料的选择性分布等。
结论综述了近年来具有三维连续网络结构的聚合物基导热复合材料的研究进展。首先从声子传输的角度简要分析了聚合物基复合材料的导热机制。重点介绍了具有连续网络结构的聚合物基导热复合材料的构筑工艺和不同类型导热填料对聚合物复合材料导热性能的影响及其机制。实现聚合物基复合材料的高导热性依赖于在基体中构筑高度连续、高质量的导热网络，这是保证高效传热的关键。通过构筑连续网络的微观结构，确保了聚合物基复合材料在低填料含量下的高导热性能，为高导热复合材料的设计提供了独特的灵活性和通用性。
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