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Nosaka M, Tsujioka K, Matsuo Y, Okamatsu T, Arita T, Shimomura M, Hirai Y. Effect of the Microstructures on Vulcanized Rubber Frictions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:6459-6467. [PMID: 34003659 DOI: 10.1021/acs.langmuir.1c00590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Vulcanized rubber is widely used in a wide range of applications because of its flexibility, durability, sealing properties, and high degree of friction. However, this high degree of friction can also become an issue, as it leads to the wearing and breakage of parts. In this report, we investigated the effects of the vulcanized rubber microstructures on friction force by using simple, anisotropic microstructures. The line and space master microstructures were prepared from a photoresist, and the structures were transferred to PDMS, PSt, and then Ni. After surface modification of the Ni microstructures by TEOS, the vulcanized rubber microstructures were fabricated by a simple hot press process with the TEOS-coated Ni microstructure molds. The structural parameters of the vulcanized rubber line and space microstructures were found to be successfully varied by elongation, and the structural deformations were also investigated by FEM simulations. Measurements of the frictional force of the vulcanized rubber microstructures revealed the friction coefficient was reduced by the surface microstructures and was affected by the directions of the contact because of the microstructure anisotropy. The reason for of these results can be explained by the changes in the contact area and hysteresis friction. These results suggest that the friction coefficients of vulcanized rubbers can be reduced by the simple surface microstructures that are applicable to a wide range of fields.
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Affiliation(s)
- Masanaru Nosaka
- Graduate school of Photonics Science, Chitose Institute of Science and Technology (CIST), 758-65, Bibi, Chitose 066-8655, Japan
| | - Kazuma Tsujioka
- Graduate school of Photonics Science, Chitose Institute of Science and Technology (CIST), 758-65, Bibi, Chitose 066-8655, Japan
| | - Yasutaka Matsuo
- Nanotechnology Research Center, Research Institute for Electronic Science (RIES), Hokkaido University, N21W10, Kita-ku, Sapporo, 011-0021, Japan
| | - Takahiro Okamatsu
- the Yokohama Rubber Co., Ltd, 2-1, Oiwake, Hiratsuka 254-8601, Japan
| | - Toshihiko Arita
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1, Katahira, Sendai 980-8577, Japan
| | - Masatsugu Shimomura
- Graduate school of Photonics Science, Chitose Institute of Science and Technology (CIST), 758-65, Bibi, Chitose 066-8655, Japan
- Department of Applied Chemistry and Bioscience, Chitose Institute of Science and Technology (CIST), Bibi 758-65, Chitose 066-8655, Japan
| | - Yuji Hirai
- Department of Applied Chemistry and Bioscience, Chitose Institute of Science and Technology (CIST), Bibi 758-65, Chitose 066-8655, Japan
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Khafidh M, Schipper DJ, Masen MA. The Formation of a Modified Surface Layer on Elastomeric Materials. TRIBOLOGY LETTERS 2019; 67:27. [PMID: 30872906 PMCID: PMC6383631 DOI: 10.1007/s11249-019-1140-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 01/19/2019] [Indexed: 06/09/2023]
Abstract
Surface modification of an elastomer may be formed during sliding contact with a rigid counter surface. This alteration leads to a change of mechanical properties at the surface and as a result a change in frictional behavior. Therefore, investigations related to the formation of a modified surface layer on elastomers and its effect on friction are of importance. In the present study, the formation of a modified surface layer on elastomer reinforced by silica is studied. Sliding friction is performed using a pin-on-disc tribometer. Several parameters are varied, namely contact pressure, velocity, and roughness of the counter surface. The existence of a modified surface layer is investigated by using a scanning electron microscope. The results show that the existence of a modified surface layer depends on the competition between the formation rate of the layer and the wear rate. The formation of the layer depends on the contact pressure, velocity, and sliding distance. A general formulation to calculate the volume of formation is proposed. Furthermore, a map of the formation of a modified surface layer is developed.
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Affiliation(s)
- M. Khafidh
- Faculty of Engineering Technology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands
- Dutch Polymer Institute DPI, P.O. Box 902, 5600AX Eindhoven, The Netherlands
| | - D. J. Schipper
- Faculty of Engineering Technology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands
| | - M. A. Masen
- Department of Mechanical Engineering, Imperial College London, Exhibition Road, London, SW7 2AZ UK
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Yazdani-Ahmadabadi H, Rastegar S, Ranjbar Z. A modified De-Gennes's trumpet model for the prediction of practical adhesion of dynamically- and structurally heterogeneous polymeric networks on solid surfaces. RSC Adv 2015. [DOI: 10.1039/c5ra05309a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A theoretical model for the prediction of practical adhesion of dynamically- and structurally heterogeneous polymeric networks on solid surfaces.
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Affiliation(s)
| | - Saeed Rastegar
- Faculty of Polymer Engineering and Color Technology
- Amirkabir University of Technology
- Tehran
- Iran
| | - Zahra Ranjbar
- Department of Surface Coatings and Corrosion
- Institute for Color Science and Technology
- Tehran
- Iran
- Center of Excellence for Color Science and Technology
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Gillies AG, Puthoff J, Cohen MJ, Autumn K, Fearing RS. Dry self-cleaning properties of hard and soft fibrillar structures. ACS APPLIED MATERIALS & INTERFACES 2013; 5:6081-6088. [PMID: 23786527 DOI: 10.1021/am400839n] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Recently, gecko-inspired synthetic adhesives (GSAs) have been made using a variety of fabrication techniques and materials, with one made from a hard polymer having been reported to recover its shear adhesion after fouling by normal use, or "dry self-clean", a feature useful for applications in wall crawling robots, reusable adhesives, microfabrication and solar panel cleaning. This paper investigates the impact of two design parameters on the dry self-cleaning capability of GSAs by experimentally testing two GSAs after fouling with small (1 μm), medium (3-10 μm), and large (40-50 μm) particles. We found that a GSA made from a hard thermoplastic with nanoscopic fibers was able to recover 96-115% of its shear adhesion after fouling with small and large but not medium particles, while a GSA made from a soft polymer and microscopic fibers recovered 40-55% on medium and large particles, with SEM imaging revealing particles embedding within the polymer. An analysis of the contact strength between fibers, particles and substrates of various dimensions and elasticity reveals that dry self-cleaning will be more effective for GSAs fabricated with smaller fiber diameters and for GSAs fabricated from materials with smaller loss functions, such as hard thermoplastics. These results have important implications on the choice of materials and geometries used for GSAs when dry self-cleaning capability is a desired function in the material.
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Affiliation(s)
- Andrew G Gillies
- Department of Mechanical Engineering, University of California, Berkeley, California 94720, United States.
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Adams MJ, Johnson SA, Lefèvre P, Lévesque V, Hayward V, André T, Thonnard JL. Finger pad friction and its role in grip and touch. J R Soc Interface 2012; 10:20120467. [PMID: 23256185 DOI: 10.1098/rsif.2012.0467] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Many aspects of both grip function and tactile perception depend on complex frictional interactions occurring in the contact zone of the finger pad, which is the subject of the current review. While it is well established that friction plays a crucial role in grip function, its exact contribution for discriminatory touch involving the sliding of a finger pad is more elusive. For texture discrimination, it is clear that vibrotaction plays an important role in the discriminatory mechanisms. Among other factors, friction impacts the nature of the vibrations generated by the relative movement of the fingertip skin against a probed object. Friction also has a major influence on the perceived tactile pleasantness of a surface. The contact mechanics of a finger pad is governed by the fingerprint ridges and the sweat that is exuded from pores located on these ridges. Counterintuitively, the coefficient of friction can increase by an order of magnitude in a period of tens of seconds when in contact with an impermeably smooth surface, such as glass. In contrast, the value will decrease for a porous surface, such as paper. The increase in friction is attributed to an occlusion mechanism and can be described by first-order kinetics. Surprisingly, the sensitivity of the coefficient of friction to the normal load and sliding velocity is comparatively of second order, yet these dependencies provide the main basis of theoretical models which, to-date, largely ignore the time evolution of the frictional dynamics. One well-known effect on taction is the possibility of inducing stick-slip if the friction decreases with increasing sliding velocity. Moreover, the initial slip of a finger pad occurs by the propagation of an annulus of failure from the perimeter of the contact zone and this phenomenon could be important in tactile perception and grip function.
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Affiliation(s)
- Michael J Adams
- School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, UK.
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Momozono S, Nakamura K, Kyogoku K. Erratum: “Theoretical model for adhesive friction between elastomers and rough solid surfaces” [J. Chem. Phys. 132, 114105 (2010)]. J Chem Phys 2010. [DOI: 10.1063/1.3469785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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