TY - JOUR

T1 - Why do metals become superhydrophilic during nanosecond laser processing? Design of superhydrophilic, anisotropic and biphilic surfaces

AU - Vasiliev, Mikhail M.

AU - Shukhov, Yuri G.

AU - Rodionov, Alexey A.

AU - Sulyaeva, Veronica S.

AU - Markovich, Dmitriy M.

AU - Starinskiy, Sergey V.

N1 - The research is founded by the Russian Science Foundation , grant No 19-79-30075 , https://rscf.ru/en/project/19-79-30075/. The experimental equipment (SEM) was provided by the Ministry of Science and Higher Education of the Russian Federation . Sergey Starinskiy personally acknowledges the state contract IT SB RAS (№121031800214-7).

PY - 2024/4/30

Y1 - 2024/4/30

N2 - This research investigates the impact of the surrounding environment on the characteristics of copper, nickel and tin during nanosecond laser processing. By comparing the results of processes conducted in vacuum and air, we conclude that changes in wetting properties cannot be solely attributed to development of surface microstructure. To elucidate this phenomenon, we conducted model experiments using a tin target. Laser processing parameters for the tin target were established, involving deep cavity melting without ablation, resulting in highly evolved material morphology. Under these conditions, laser processing in air did not lead to metal hydrophilization. Therefore, our study demonstrates that the primary cause of changes in material wetting properties during nanosecond laser processing is the re-deposition of ablation products onto the material surface. These products form a nanoporous layer that enhances wicking capabilities and subsequently serves as a sorbent for various impurities, gradually leading to the hydrophobization of most commonly used materials. The proposed mechanism opens the possibility for the development of new methods to create materials with biphilic and anisotropic wetting properties. The key insight lies in the control of the thickness of the nanoporous layer, as it emerges as a pivotal factor dictating wettability properties and wicking capability.

AB - This research investigates the impact of the surrounding environment on the characteristics of copper, nickel and tin during nanosecond laser processing. By comparing the results of processes conducted in vacuum and air, we conclude that changes in wetting properties cannot be solely attributed to development of surface microstructure. To elucidate this phenomenon, we conducted model experiments using a tin target. Laser processing parameters for the tin target were established, involving deep cavity melting without ablation, resulting in highly evolved material morphology. Under these conditions, laser processing in air did not lead to metal hydrophilization. Therefore, our study demonstrates that the primary cause of changes in material wetting properties during nanosecond laser processing is the re-deposition of ablation products onto the material surface. These products form a nanoporous layer that enhances wicking capabilities and subsequently serves as a sorbent for various impurities, gradually leading to the hydrophobization of most commonly used materials. The proposed mechanism opens the possibility for the development of new methods to create materials with biphilic and anisotropic wetting properties. The key insight lies in the control of the thickness of the nanoporous layer, as it emerges as a pivotal factor dictating wettability properties and wicking capability.

KW - Anisotropic

KW - Biphilic

KW - Laser processing

KW - Nanosecond laser ablation

KW - Superhydrophilic

KW - Surface morphology

KW - Wettability

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85183472562&origin=inward&txGid=c35ec50eb72ae5e028bbb68a7cab5a53

UR - https://www.mendeley.com/catalogue/df700099-f431-31a0-9047-60a24f3f56e3/

U2 - 10.1016/j.apsusc.2024.159392

DO - 10.1016/j.apsusc.2024.159392

M3 - Article

VL - 653

JO - Applied Surface Science

JF - Applied Surface Science

SN - 0169-4332

M1 - 159392

ER -