Compositions and Methods for Reducing Friction at a Solid:Liquid Interface

Abstract

Compositions and devices are provided that provide a persistent low-friction coating on a solid surface, by application of a mixture of a polyethylene glycol-containing surfactant and a vegetable to the surface. The coating thus generated does not require replenishing during use and persists through rinsing and multiple uses. Surprisingly, markedly reduced friction is found when the surfactant is provided at 3% w/v to 7% w/v in the composition. Such compositions and methods are suitable for application to both mixing and separation operations. Formulation of such compositions with food grade components permits use in food processing.

What is claimed is: 
     
         1 . A coating composition for generating a persistent reduced friction surface, comprising:
 a vegetable oil; and   a surfactant comprising polyethylene glycol,   wherein the surfactant is present at from 3% w/v to 7% w/v, and wherein the coating composition generates the persistent reduced friction surface when applied to a solid surface.   
     
     
         2 . The coating composition of  claim 1 , wherein the persistent reduced friction surface shows an 80% or greater reduction in friction relative to a treated surface generated by contacting the solid surface with a corresponding coating composition in which the surfactant is present at less than 3% w/v or greater than 7% w/v. 
     
     
         3 . The method of  claim 1 , wherein the vegetable oil is selected from the group consisting of almond oil, beech nut oil, brazil nut oil, cashew oil, coconut oil, corn oil, cottonseed oil, grapefruit seed oil, hazelnut oil, lemon oil, macadamia nut oil, mongogo nut oil, olive oil, orange oil, palm oil, peanut oil, pecan oil, pine nut oil, pistachio nut oil, pumpkin seed oil, rapeseed/canola oil, safflower oil, sesame oil, soybean oil, sunflower oil, and walnut oil. 
     
     
         4 . The composition of  claim 1 , wherein the vegetable oil is a non-degummed soybean oil. 
     
     
         5 . The composition of  claim 1 , wherein the surfactant comprising polyethylene glycol is a food-grade surfactant. 
     
     
         6 . The composition of  claim 1 , wherein the surfactant comprising polyethylene glycol is selected from the group consisting of a surfactant containing polyethylene glycol, a surfactant containing a polyethylene glycol/polypropylene glycol copolymer, a surfactant containing a polyethylene glycol ether, a surfactant containing a polyethylene glycol/polypropylene glycol copolymer ether, a surfactant containing an alkylated polyethylene glycol ether, a surfactant containing a polyethylene glycol/polypropylene glycol copolymer ether, a surfactant containing an ethoxylate of an alkylated polyethylene glycol ether, and a surfactant containing an ethoxylate of a polyethylene glycol/polypropylene glycol copolymer ether. 
     
     
         7 . A centrifugal separator comprising a reduced friction surface, wherein the reduced friction surface comprises a coating composition of  claim 1 . 
     
     
         8 . A food processing surface comprising a reduced friction surface wherein the reduced friction surface comprises a coating composition of  claim 1 . 
     
     
         9 . A device for suspending a particulate solid in a liquid, wherein the device comprises a reduced friction surface, and wherein the reduced friction surface comprises a coating composition of  claim 1 .