图1 碳球制备示意图

Fig. 1 Formation process of the carbon spheres

图2 邻苯三酚与甲醛摩尔比为(a)2:1、(b)1:1、(c)1:2和(d)1:4时对酚醛树脂微球形貌的影响

Fig. 2 Effects of molar ratios of pyrogallic acid to formaldehyde at (a) 2:1, (b) 1:1, (c) 1:2, and (d) 1:4 on morphologies of phenolic resin spheres

图3 邻苯三酚与甲醛摩尔比为(a)2 : 1、(b)1 : 1、(c)1 : 2和(d)1 : 4时对酚醛树脂微球直径的影响

Fig. 3 Effects of molar ratios of pyrogallol to formaldehyde at (a) 2 : 1, (b) 1 : 1, (c) 1 : 2, and (d) 1 : 4 on particle sizes of phenolic resin spheres

图4 酚醛树脂微球(a)煅烧前与(b)煅烧后的TEM照片及其(c)动态光散射粒度分析曲线和(d)煅烧后的碳球在N2气氛下的热重分析曲线

Fig. 4 TEM morphologies of phenolic resin spheres (a) before and (b) after calcination, their (c) particle size analysis curves of dynamic light scattering and (d) thermogravimetric analysis curve of carbon spheres after calcination in N2 atmosphere

图5 微球煅烧前后的(a)傅里叶红外光谱图和(b)拉曼光谱图及其(c)碳球分散到不同介质中的Zeta电位和(d)在808 nm处吸光度随时间变化的百分比

Fig. 5 (a) FT-IR and (b) Raman spectra of phenolic resin spheres before and after calcination, (c) Zeta potential of carbon spheres in different dispersion medium and (d) absorbance percent of carbon spheres in different dispersion medium at 808 nm

图6 碳球的光热性能测试

Fig. 6 Evaluation of photothermal effect of carbon spheres Influence of (a) laser power density (concentration: 100 μg/mL) and (b) concentration of carbon spheres (laser power density: 0.8 W/cm2) on photothermal effect; (c) Cloud images of temperature changes; (d) Measurement of the photothermal stability (concentration: 100 μg/mL, laser power density: 0.8 W/cm2)

图7 碳球的光热转换效率测试

Fig. 7 Measurement of the photothermal conversion efficiency of carbon spheres (a) Heating and cooling curves of carbon sphere suspension (concentration: 100 μg/mL, laser power density: 0.8 W/cm2); (b) Linear fitting curve of t and -lnθ at cooling phase; (c) UV-visible absorption curve of carbon sphere suspension

图8 不同浓度的碳球与HaCaT细胞共培养24 和48 h后的细胞存活率

Fig. 8 Viability of HaCaT cells co-cultured with different concentrations of carbon spheres for 24 and 48 h

图9 碳球在近红外光照射不同时长处理时对肿瘤细胞的光热杀伤效果

Fig. 9 Photothermal killing effect of carbon spheres on tumor cells with different laser irradiation time

图10 含碳球的肿瘤细胞悬液经不同时长近红外光照射后的活、死细胞荧光照片

Fig. 10 Live/dead fluorescence images of tumor cells co-culcured with carbon spheres by different laser irradiation time (Green: live cells; Red: dead cells; Scale bar=200 μm)