热处理温度对类球形磺化石墨烯微结构的影响

Effect of heat treatment temperature on the microstructure of spherical sulfonated graphene particles

以非晶态高分子聚合物为碳源,在特定温度的苯磺酸溶液中,一次性脱氢及同步自缩聚制备磺化石墨烯悬浊液,再经喷雾式干燥制得类球形磺化石墨烯颗粒。采用SEM、TEM、BET、FT-IR、Raman和XRD等表征手段对不同热处理温度下的磺化石墨烯颗粒进行表征;研究类球形磺化石墨烯在750、1 500和2 500℃热处理后的形貌及结构变化;考察不同热处理温度对其表面特性和结晶程度的影响。结果表明,球形磺化石墨烯颗粒的直径尺寸随着热处理温度的升高而逐渐减小,ID/IG值先升高后降低,Lc值由1.55 nm(未热处理)升高到8.08 nm(2 500℃),微晶堆叠厚度增加,结晶程度提高,结构由无序向有序化转变。

Sulfonated graphene was prepared by heat treating a mixture of polyvinyl chloride and benzenoic acid( 4 ∶1 wt/wt) first at 130 ℃ for 4 h and then at 180 ℃ for 12 h. The sulfonated graphene( 10 wt%) suspension was spay-dried to obtain spherical sulfonated graphene particles. The morphology and structure of the spherical particles before and after heat treatment at 750,1 500 and2 500 ℃( HTT) were characterized by SEM,TEM,BET,FT-IR,Raman and XRD. Results indicate that the diameters of the particles decrease gradually with increasing HTT,their ID/IG values first increase and then decrease,and the Lc values increase from1.55( unheated) to 8.08 nm( 2 500 ℃) . The crystallinity and layer thickness of the graphene increase with increasing HTT and the spherical morphology is retained after the heat treatment at 2 500 ℃.