摘要
采用高速剪切机液相剥离法,在胆酸钠的水溶液中将鳞片石墨剥离,离心得到石墨烯分散液。AFM、TEM、Raman表征结果发现,剥离出的石墨烯厚度小于4层,尺寸大约在2~3μm,高质量缺陷少(I_D/I_G≈0.15)。将石墨烯分散液冷冻干燥后与银粉共同添加到硅橡胶中,制备出导热硅橡胶。利用稳态热流法测试导热硅橡胶的导热系数发现,当添加3vol%石墨烯时,复合材料的导热系数由未添加石墨烯时的4.900 W/(m·K)提高到12.367 W/(m·K)。综上所述,通过液相剥离法成功制备出缺陷较少的少层石墨烯,能够与银粉协同提高导热硅橡胶的导热系数。
Graphene dispersion was produced by centrifugation after exfoliating the graphite in aqueous solutions containing sodium cholate as a surfactant with high speed shearing machine. The exfoliated graphene （thickness≤4 layers） showing large lateral size of around 2-3 μm and high quality （ID/IG≈0.15） was characterized by atomic force microscopy （AFM）, transmission electron microscopy （TEM）, and Raman spectroscopy. After freeze drying, Graphene was added in the silver-silicone rubber to produce a hybrid graphene-metal thermal conductive silicone rubber, and steady-state heat flow method was applied to study the thermal conductivity of the composite. It was found that as filler loading fraction of graphene increased from 0 to 3vol%, thermal conductivity of siliver-silicone rubber dramatically improved from 4.9 W/（m·K）to 12.367 W/（m·K）. This result suggests that little-defect graphene with few layers prepared by exfoliating can significantly enhance the thermal conductivity of silicone rubber by synergy effect when combined with silver powder.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2017年第9期955-960,共6页
Journal of Inorganic Materials
关键词
液相剥离法
石墨烯
热导率
liquid exfoliation graphene thermal conductivity
