Enhanced Adsorption of Epoxy‐Functional Nanoparticles onto Stainless Steel Significantly Reduces Friction in Tribological Studies

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.

Recent Advances in Polymerization‐Induced Self‐Assembly (PISA) Syntheses in Non‐Polar Media

“…Working in collaboration with Lubrizol scientists, György et al examined the relationship between enhanced nanoparticle adsorption and friction reduction. [18] The adsorption of ~27 nm epoxy-functional P(LMA 50 -stat-Gly-MA 9 )-PMMA 67 , PLMA 63 -PGlyMA 89 and non-functional PLMA 63 -PMMA 67 nanoparticles onto stainless steel from ndodecane was examined using a quartz crystal microbalance with dissipation (QCM-D). Locating the epoxy groups within the stabilizer block of the nanoparticles led to a significantly higher adsorbed amount (7.6 mg m À 2 ) compared to that obtained for epoxy-core functional nanoparticles (3.7 mg m À 2 ) or non-functional nanoparticles (3.8 mg m À 2 ) at 20 °C.…”

“…[29,30] However, it is rarely cost-effective to do so for many potential applications. Nevertheless, RAFT PISA syntheses in non-polar media have been examined by companies such as Lubrizol, L'Oréal and Ashland to produce nanoparticles for lubrication applications [18,31,32] or personal care products. [33,34] In principle, diblock copolymer nanoparticles can be prepared in non-polar media via RAFT PISA using either a two-pot [33,[35][36][37] or a one-pot protocol.…”

Recent Advances in Polymerization‐Induced Self‐Assembly (PISA) Syntheses in Non‐Polar Media

“…Chemie nanoparticle adsorption and friction reduction. [18] The adsorption of ~27 nm epoxy-functional P(LMA 50 -stat-Gly-MA 9 )-PMMA 67 , PLMA 63 -PGlyMA 89 and non-functional PLMA 63 -PMMA 67 nanoparticles onto stainless steel from ndodecane was examined using a quartz crystal microbalance with dissipation (QCM-D). Locating the epoxy groups within the stabilizer block of the nanoparticles led to a significantly higher adsorbed amount (7.6 mg m À 2 ) compared to that obtained for epoxy-core functional nanoparticles (3.7 mg m À 2 ) or non-functional nanoparticles (3.8 mg m À 2 ) at 20 °C.…”

Single-ion nano-features formed by a Li-containing block copolymer synthesized via PISA

“…14,15 So far, many different combinations of shell- and core-forming blocks have been used in the PISA process and the resulting nano-objects have been used for many different types of applications from stem-cell growth, drug delivery and smart coatings to separation membranes. 16–26…”

“…14,15 So far, many different combinations of shell-and core-forming blocks have been used in the PISA process and the resulting nano-objects have been used for many different types of applications from stem-cell growth, drug delivery and smart coatings to separation membranes. [16][17][18][19][20][21][22][23][24][25][26] In recent years, solid polymer electrolytes (SPEs) have gained a great deal of attention as they offer advantages for improving the safety of existing lithium batteries. 27,28 SPEs are excellent due to their mechanical strength and flexibility.…”