Gemini Interfaces in Aqueous Lubrication with Hydrogels

Mesh Size Control of Polymer Fluctuation Lubrication in Gemini Hydrogels

“…In previous work on Gemini hydrogel friction, we found that the lubrication curve differed dramatically from the classical engineering Stribeck curve in several major ways [16,37]. First, at slow sliding speeds, where the effects of hydrodynamic lubrication are negligible, Gemini hydrogel friction is actually lowest.…”

“…Gemini hydrogel interfaces can provide exceptionally low friction coefficients under conditions traditionally not thought to promote lubrication, namely, low contact pressure and low sliding speed [16,37]. In the series of experiments described here, the samples with the largest mesh size (ξ = 9.4 ± 1.1 nm) exhibited the lowest measured friction coefficients (µ ~ 0.005), and maintained this behavior over a range of sliding speeds from V s = 30-1,000 µm s -1 .…”

“…Hydrogels are crosslinked networks of polymer chains that are swollen with water; a representative flexible polymeric hydrogel network is illustrated in Figure 1. Hydrogels are water-permeable materials, which can be easily created with varying mesh size (), water content, permeability, and elastic properties [15][16][17][18].…”

In vitro friction testing of contact lenses and human ocular tissues: Effect of proteoglycan 4 (PRG4)

“…This could be due to a higher affinity of PRG4 for eyelid tissue, which is suggestive of potential broad clinical application, yet a~45% reduction was also observed for narafilcon A articulated against a cornea indicating PRG4 can effectively reduce friction at both lens biointerfaces. Other studies evaluating the kinetic friction of senofilcon A lenses gave values ranging from $0.03 (whole lens on mucin-coated glass [29]) to $ 0. various loading and sliding conditions likely behaves differently than non-porous, hard materials, making it a very complex and difficult model to study using classical tribological methods such as Stribeck analysis [44]. Furthermore, physiological interactions between lenses and ocular tissues may not be replicated at lenssynthetic surface biointerfaces.…”

Effects of polymerization degree on recovery behavior of PVA/PVP hydrogels as potential articular cartilage prosthesis after fatigue test

“…PVA hydrogel has been one of the most widely used polymer as a potential articular cartilage substitute due to its excellent biocompatibility, good load-bearing properties, and can be easily processed and modified [12,18]. The swelling behavior [19,20], mechanical properties [21,22], and biotribological properties [23][24][25] of PVA hydrogels has been widely characterized by researchers. Tadavarthy et al [26] found no adverse effects in surrounding tissue after implanting PVA gels subcutaneously or intramuscularly into rabbits.…”