批量生产各规格石墨烯蒙烯氧化铝纤维织物，用现代电子和仪器仪表

摘要：随着电子设备和仪器的日益复杂，多功能材料对于简化设计至关重要。电热和电磁功能是常用的功能，通常由不同的材料提供。将它们集成到单一材料中，可以减少元件，实现系统微型化。同时，需要具有广泛可调电气和电磁特性的材料，以满足从电磁波传输到屏蔽以及在宽温度范围内电加热等

1成果简介

随着电子设备和仪器的日益复杂，多功能材料对于简化设计至关重要。电热和电磁功能是常用的功能，通常由不同的材料提供。将它们集成到单一材料中，可以减少元件，实现系统微型化。同时，需要具有广泛可调电气和电磁特性的材料，以满足从电磁波传输到屏蔽以及在宽温度范围内电加热等各种应用要求。本文，北京大学与北京石墨烯研究院刘忠范-亓月课题组在《ADVANCED MATERIALS》期刊发表名为“Graphene-skinned Alumina fiber Fabric for Diverse Electrothermal and Electromagnetic Compatibility and Its Mass Production”的论文，研究通过在氧化铝纤维织物（AFF）的每根纤维上进行石墨烯化学气相沉积（CVD），开发出了具有广泛可调电气和电磁特性的石墨烯蒙烯氧化铝纤维织物（GAFF）。

通过调节石墨烯厚度和AFF孔径，GAFF的片状电阻（1-10 000Ω·sq−1）、电热能力（高达约1400 °C）以及电磁反射率（约0.003至0.91）和透射率（约0.98至0.0001）均具有广泛的可调性。各种规格的 GAFF 已实现批量生产，可用于多种应用。制备出了具有高电磁反射率和低透射率的加热-屏蔽一体化器件（GAFF-HS），以及具有低电磁反射率和高透射率的加热-传输兼容器件（GAFF-HT），这两种器件分别针对不同的应用领域：电磁干扰屏蔽系统和雷达系统的电热防/除冰。具有广泛可调多功能的GAFF有望在现代电子和仪器仪表的各种应用中取得重大进展。

2图文导读

图1、Preparation of GAFF and its mechanical and electrical properties. a) Schematic of GAFF prepared via CVD process. b, c) SEM images of the front b) and side c) views of GAFF. d) High-magnification SEM image of GAFF. e) Raman spectra 2D peak (≈2700 cm−1) mapping of individual fiber in GAFF. f) Raman spectra (normalized to G peak intensity) of GAFF grown with C/H of 100:500, 100:700, 100:1000. With C/H increasing, the intensity ratio of 2D (≈2700 cm−1) and G (≈1580 cm−1) peaks (I2D/IG) in Raman spectra reduce. g) Sheet resistance mapping of GAFF with a size of 20 cm × 1 m, showing an average value of 100.3 ± 2.2 Ω·sq−1 (growth conditions: ≈1100 °C, 500 sccm Ar,100 sccm CH4, 500 sccm H2, ≈130 min). Inset is the distribution of sheet resistances. h) Wide range of graphene thickness and sheet resistance of GAFF obtained by modulating the growth time of graphene (growth conditions: ≈1100 °C, 500 sccm Ar, 500 sccm H2, 100 sccm CH4, growth time 30–200 min). i) Conductivity comparations of graphene-skinned alumina fiber (GAF), commercially available alloy fiber, and carbon fiber. j) Tensile strength of the pristine AFF and GAFFs obtained with different graphene growth times at ≈1100 °C. k) Photographs of GAFF going through a series of mechanical deformations of grasping, folding, twisting, and releasing (each deformation action was repeated 10 times).

图2、Broadly tunable electrothermal performances of GAFF. a) Infrared image of GAFF heater at a heating temperature of 150.1 ± 1.6 °C (20 cm × 0.5 m, ≈10 Ω·sq−1, 44.5 V voltage input). b, c) Temperature profiles of GAFF heater at different power densities (b) and the enlarged view (c) of the temperature rising and falling processes. d) Power densities for GAFF heaters with different sheet resistances at varying input voltages. e) Saturated temperatures and heating rates of GAFF heaters with different sheet resistances under input voltages of 30 and 100 V. f) Comparison of temperature switching response between GAFF and Nichrome fiber heaters. Two heaters have the same resistance of ≈1.6 Ω, and both input voltages are 5 V. g) Photograph of copper (Cu) foils melting on GAFF heater in a vacuum environment. Insets show the photograph of Cu foils before and after melting. h) Temperature curves collected on GAFF heater and Cu foils. i) Temperature distribution along the white dashed line in (g). j) Long-term heating stability of GAFF heater at a working temperature of ≈1200 °C and ≈1400 °C in a vacuum environment (the temperatures were collected every 30 min).

图3、Broadly tunable electromagnetic properties of GAFF. a, b) Schematic for the electromagnetic performances of GAFFs with different graphene coating thickness and pore size. Thin graphene coating deposition on large-pore-size AFF leads to low electromagnetic reflection and high transmission (a), while thick graphene coating deposition on small-pore-size AFF leads to high electromagnetic reflection and low transmission (b). c) Real (ε′) and imaginary (ε′′) parts of the permittivity of GAFFs with different graphene thicknesses across the frequency range of 2–18 GHz. d) Electromagnetic reflectivity (2–18 GHz) of GAFFs with different graphene coating thicknesses. e) Electromagnetic transmissivity (T), absorptivity (A), and reflectivity (R) (2-18 GHz) of GAFFs with graphene thicknesses of ≈0.9 nm and ≈70.1 nm. f) Electromagnetic reflectivity (R), absorptivity (A), and transmissivity (T) (2–18 GHz) of GAFFs with sheet resistances in the range of 2–10000 Ω·sq−1. g) Average permittivity (ε′ and ε′′), reflectivity (R), absorptivity (A), and transmissivity (T) of GAFFs with different air-to-material ratios. h) Statistics of electromagnetic reflectivity of GAFFs with different air-to-material ratios and graphene coating thicknesses. Regions marked in red and blue ellipses, denoted as the
conducting-shielding-integrated part and conducting-transmitting-compatible part, indicate the conductive applications of GAFF in electromagnetic shielding and electromagnetic transmitting scenarios, respectively.

图4、Mass productions and applications of different specifications of GAFFs. a) Two specifications of GAFFs prepared by a homemade roll-to-roll CVD growth system. GAFF-1, small-pore-size (≈0.005 mm2) GAFF with thick graphene coating, with sheet resistance of 9.8 ± 0.3 Ω·sq−1. GAFF-2, large-pore-size (≈0.1 mm2) GAFF with thin graphene coating, with sheet resistance of 3001.4 ± 117.1 Ω·sq−1. b) SEM images of GAFF-1 and GAFF-2 in (a). c) Schematic diagram of GAFFs exhibiting a broad range of adjustable
electrothermal-electromagnetic-compatible performances. The left part denotes heating-shielding-integrated device (GAFF-HS) fabricated based on GAFF-1. The right part denotes heating-transmitting-compatible device (GAFF-HT) fabricated based on GAFF-2. d) EMI SE (2-18 GHz) of GAFF-HS with varying stacking numbers of GAFF-1 (with a thickness of ≈0.3, ≈0.5, ≈0.7, ≈0.9, and ≈1.1 mm, respectively) at different heating temperatures. e) Schematic diagram of GAFF-HS used in shielding room de-/anti-icing. f) Transmissivity (2–18 GHz) of GAFF-HT at different heating temperatures. g) Schematic diagram of GAFF-HT used in radome de-/anti-icing.

3小结

本研究开发了一种新型石墨烯复合材料GAFF，它具有优异的机械强度、柔韧性和轻质特性。通过石墨烯厚度控制和织物结构设计，GAFF 实现了电气和电磁性能的大范围可调。这种广泛的可调性使GAFF能够满足从电磁波传输到屏蔽以及从低温到高温的电加热等各种应用要求。GAFF-HS 具有高电磁反射率和低透射率的特点，而 GAFF-HT 则具有低电磁反射率和高透射率的特点，它们是根据 GAFF 的不同规格制造的，分别针对电磁干扰屏蔽系统和电磁通信系统的防/除冰应用。值得一提的是，本研究利用自制的卷对卷CVD系统实现了各种规格GAFF的批量生产，为这种新材料的实际应用奠定了坚实的基础。GAFF 的应用前景令人期待。随着电子产品和仪器仪表的复杂性不断提高，对多功能材料的需求也日益增加，这对减少元件数量和简化系统结构至关重要。电子和电磁功能是电子和仪器仪表中常用的功能，通常由不同的材料提供。GAFF成功地将这些功能集成在一起，并使它们具有广泛的可调性，这有望在现代电子和仪器仪表的各种应用中取得重大进展。

文献：