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Enhanced Adsorption of Epoxy-Functional Nanoparticles onto Stainless Steel Significantly Reduces Friction in Tribological Studies |
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| Authors: | Dr. Csilla György Dr. Paul M. Kirkman Dr. Thomas J. Neal Dr. Derek H. H. Chan Megan Williams Dr. Timothy Smith Dr. David J. Growney Prof. Steven P. Armes |
| Affiliation: | 1. Dainton Building, Department of Chemistry, University of Sheffield, Sheffield, South Yorkshire, S3 7HF UK Contribution: Data curation (lead), Formal analysis (lead), Investigation (lead), Methodology (lead), Writing - original draft (supporting), Writing - review & editing (supporting);2. Lubrizol Ltd., Hazelwood, Derbyshire, DE56 4AN UK Contribution: Formal analysis (supporting), Investigation (supporting), Methodology (supporting), Supervision (supporting);3. Dainton Building, Department of Chemistry, University of Sheffield, Sheffield, South Yorkshire, S3 7HF UK Contribution: Formal analysis (supporting), Investigation (supporting), Methodology (supporting);4. Dainton Building, Department of Chemistry, University of Sheffield, Sheffield, South Yorkshire, S3 7HF UK Contribution: Investigation (supporting), Methodology (supporting);5. Lubrizol Ltd., Hazelwood, Derbyshire, DE56 4AN UK Contribution: Formal analysis (supporting), Investigation (supporting), Methodology (supporting);6. Lubrizol Ltd., Hazelwood, Derbyshire, DE56 4AN UK Contribution: Funding acquisition (supporting), Investigation (supporting), Project administration (supporting), Resources (supporting), Supervision (supporting);7. Lubrizol Ltd., Hazelwood, Derbyshire, DE56 4AN UK Contribution: Supervision (supporting);8. Dainton Building, Department of Chemistry, University of Sheffield, Sheffield, South Yorkshire, S3 7HF UK |
| Abstract: | Epoxy-functional sterically-stabilized diblock copolymer nanoparticles (ca. 27 nm) are prepared via RAFT dispersion polymerization in mineral oil. Nanoparticle adsorption onto stainless steel is examined using a quartz crystal microbalance. Incorporating epoxy groups within the steric stabilizer chains results in a two-fold increase in the adsorbed amount, Γ, at 20 °C (7.6 mg m−2) compared to epoxy-core functional nanoparticles (3.7 mg m−2) or non-functional nanoparticles (3.8 mg m−2). A larger difference in Γ is observed at 40 °C; this suggests chemical adsorption of the nanoparticles rather than merely physical adsorption. A remarkable near five-fold increase in Γ is observed for ca. 50 nm epoxy-functional nanoparticles compared to non-functional nanoparticles (31.3 vs. 6.4 mg m−2, respectively). Tribological studies confirm that chemical adsorption of the latter epoxy-functional nanoparticles leads to a significant reduction in friction between 60 °C and 120 °C. |
| Keywords: | Epoxy-Functional Nanoparticles Polymerization-Induced Self-Assembly Quartz Crystal Microbalance RAFT Polymerization Stainless Steel |