Nanoscale wear evolution on a polystyrene/poly (n-butyl methacrylate) blend
Nanoscale wear evolution on a polystyrene/poly (n-butyl methacrylate) blend
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DOI：
10.1016/j.wear.2023.205160
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发表时间：
2023-11
期刊：
影响因子：
5
通讯作者：
H. Khaksar;Chengfu Ma;Natalia Janiszewska;K. Awsiuk;A. Budkowski;Enrico Gnecco
中科院分区：
文献类型：
--
作者：
H. Khaksar;Chengfu Ma;Natalia Janiszewska;K. Awsiuk;A. Budkowski;Enrico Gnecco
我们研究了聚苯乙烯（PS）和聚（甲基丙烯酸正丁酯）（PnBMA）薄膜作为纯材料或以1：1共混物的形式混合的早期磨损引起的表面纳米结构的形成。为此，原子力显微镜（AFM）被用来反复刮擦样品表面，测量伴随的摩擦力，并成像所得到的功能。在第一阶段，在所有情况下都形成了有序的波纹。随着这个过程的进行，小山丘在波纹的顶部成核，并以纳米塑料的形式逐渐释放，而波纹变得更宽，更不规则。在混合物表面上，更柔顺的PnBMA在开始时呈现出比PS更多的波纹状涟漪结构和更大的摩擦振荡，但是随着重复磨损测试并且混合物的原始“边缘和孔”几何形状被破坏，情况再次变得更加复杂。非常明显，如果表面被来回刮擦，而不仅仅是在一个方向上，磨损损坏会减少。扫描图案（扫描线之间的距离）和法向力（远低于和高于约50 nN的力阈值，导致第一阶段中的表面波纹）的影响也已被解决。
We have investigated the formation of surface nanostructures caused by early-stage wear of polystyrene (PS) and poly(n-butyl methacrylate) (PnBMA) thin films as pure materials, or mixed in the form of a 1:1 blend. To this end, atomic force microscopy (AFM) was used to repeatedly scratch the sample surfaces, measure the accompanying friction forces, and image the resulting features. In the very first stage ordered ripples are formed in all cases. As the process goes on, hillocks are nucleated on the crests of the ripples, and progressively released in the form of nanoplastics while the ripples become wider and less regular. On the blend surface the more compliant PnBMA presents more corrugated ripple structures and larger friction oscillations than PS in the beginning, but the scenario becomes again more complex as the wear test is repeated and the original ‘rim and hole’ geometry of the blend is disrupted. Quite noticeably, the wear damage is reduced if the surfaces are scraped forth and back and not only in one direction. The influence of the scan pattern (distance between scan lines) and of the normal force (well below and above the force threshold of about 50 nN leading to surface ripples in the first stage) have been also addressed.