Page 117 - 《摩擦学学报》2021年第5期

706 摩 擦 学 学 报 第 41 卷

2.0 2.0
(a) 1.5 (b) 2.0 (c)
1.5 1.0 1.5
Lateral force/nN −0.5 Lateral force/nN −0.5 Lateral force/nN −0.5
1.0
1.0
0.5
0.5
0.5
0.0
0.0
0.0
−1.0
−1.5
−1.5 Trace −1.0 Trace −1.0 Trace
−1.5
Retrace
Retrace
Retrace
−2.0 −2.0 −2.0
0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5
Scan distance/nm Scan distance/nm Scan distance/nm
2.5 3.5 0.4
(d) (e) (f)
2.0 3.0 0.3
Lateral force/nN 1.0 Strengthening distance/nm 2.0 Strengthening degree/ (nN/nm) 0.2
1.5
2.5
0.5
1.5
0.0
−0.5
Trace
0.5
Retrace 1.0 0.1
−1.0
0.0 0.0
0 1 2 3 4 5 1 2 3 4 1 2 3 4
Scan distance/nm Scan region Scan region
15
10 5 (g) 10 (h) 15 (i)
Lateral force/nN −5 0 Lateral force/nN −5 5 0 Lateral force/nN 5 0
10
−5
−10
Trace −10 Trace −10 Trace
−15 Retrace −15 Retrace Retrace
−15
0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5
Scan distance/nm Scan distance(nm) Scan distance(nm)
10 5 (j) (k) 4.5 1.2 (l)
4.0
1.0
Lateral force/nN −5 0 Strengthening distance/nm 3.0 Strengthening degree/ (nN/nm) 0.8
3.5
2.5
0.6
2.0
0.4
1.5
−10
Trace 1.0 0.2
−15 Retrace 0.5
0.0 0.0
0 1 2 3 4 5 1 2 3 4 1 2 3 4
Scan distance/nm Scan region Scan region

Fig. 7 (a～f): Under the action of conical probe,[(a～d): The lateral force as a function of scan distance of 4 regions from the
boundary of graphene to its central, (e) and (f) express respectively the friction strengthening distance and friction
strengthening degree of 4 scan regions]; (g～l): Under the action of spherical probe [(g～j): the lateral force as a
function of scan distance of 4 regions from the boundary of graphene to its central, (k) and (l) express
respectively the friction strengthening distance and friction strengthening degree of 4
scan regions. The applied load is 50 nN, the thickness of graphene is 1.1 nm
图 7 (a~f)是在锥形探针的作用下[其中(a~d)表示从石墨烯的边界到其中心的 4 个区域的侧向力与扫描距离之间的关系，
(e)和(f)分别表示 4 个扫描区域摩擦强化距离和程度]; (g~l)是在球形探针的作用下[其中(g~j)表示从石墨烯的边界
到其中心的4 个区域的侧向力与扫描距离之间的关系，(k)和(l)分别表示 4 个扫描区域摩擦强化距离和程度].
所施加的载荷为 50 nN，石墨烯厚度为 1.1 nm
区域和压缩接触区域. 在单层石墨烯的边界位置有一 基底的边界位置到石墨烯的中心区域时，吸附效应在

些不饱和的悬挂键，其可以吸附空气中的氮气或二氧 逐渐地减弱，对石墨烯面外变形的抑制作用也在逐渐
化碳，这种吸附作用可以抑制石墨烯的面外变形. 因 减弱，因此石墨烯的平均摩擦力在逐渐地增大. 而在
此，对于锥形探针，当探针的作用区域从石墨烯与硅 球形探针的作用下，单层石墨烯的平均摩擦力随所选