Shock absorber fluid composition containing nanostructures

• US 20060040832A1
• Filed: 10/15/2004
• Published: 02/23/2006
• Est. Priority Date: 10/15/2003
• Status: Active Grant

• Current Assignee: VGP IPCO LLC
• Original Assignee: Ashland Incorporated (Bank of Montreal)
• Inventors: Lockwood, Frances E., Wu, Gefei, Zhang, Zhiqiang, Dotson, Daniel J.
• Granted Patent: US 7,470,650 B2
• Time in Patent Office: Days
• US Class Current: 508/113
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C10M 125/02 Carbon; Graphite
• CPC Class Codes: C10M 141/00 Lubricating compositions characterised by the additive being a mixture of two or more compounds covered by more than one of the main groups C10M125/00 - C10M139/00, each of these compounds being essential
• CPC Class Codes: C10M 141/02 at least one of them being an organic oxygen-containing compound
• CPC Class Codes: C10M 141/06 at least one of them being an organic nitrogen-containing compound
• CPC Class Codes: C10M 141/10 at least one of them being an organic phosphorus-containing compound
• CPC Class Codes: C10M 161/00 Lubricating compositions characterised by the additive being a mixture of a macromolecular compound and a non-macromolecular compound, each of these compounds being essential
• CPC Class Codes: C10M 173/02 not containing mineral or fatty oils
• CPC Class Codes: C10M 2201/041 Carbon; Graphite; Carbon black
• CPC Class Codes: C10M 2203/1006 used as base material
• CPC Class Codes: C10M 2205/003 used as base material
• CPC Class Codes: C10M 2205/0206 used as base material
• CPC Class Codes: C10M 2207/282 of (cyclo)aliphatic oolycarboxylic acids
• CPC Class Codes: C10M 2207/34 Esters having a hydrocarbon substituent of thirty or more carbon atoms, e.g. substituted succinic acid derivatives
• CPC Class Codes: C10M 2207/40 Fatty vegetable or animal oils
• CPC Class Codes: C10M 2207/401 used as base material
• CPC Class Codes: C10M 2209/104 of alkylene oxides containing two carbon atoms only
• CPC Class Codes: C10M 2209/108 etherified
• CPC Class Codes: C10M 2209/109 esterified
• CPC Class Codes: C10M 2215/08 Amides
• CPC Class Codes: C10M 2215/26 : Amines
• CPC Class Codes: C10M 2215/28 : Amides; Imides
• CPC Class Codes: C10M 2217/022 : containing monomers having an unsaturated radical bound to an amino group
• CPC Class Codes: C10M 2217/028 : containing monomers having an unsaturated radical bound to a nitrogen-containing hetero ring
• CPC Class Codes: C10M 2217/041 : involving a condensation reaction
• CPC Class Codes: C10M 2223/04 : Phosphate esters
• CPC Class Codes: C10M 2223/041 : Triaryl phosphates
• CPC Class Codes: C10M 2223/045 : Metal containing thio derivatives
• CPC Class Codes: C10M 2223/06 : having phosphorus-to-carbon bonds
• CPC Class Codes: C10N 2010/04 : Groups 2 or 12
• CPC Class Codes: C10N 2020/01 : Physico-chemical properties
• CPC Class Codes: C10N 2020/06 : Particles of special shape or size
• CPC Class Codes: C10N 2020/061 : Coated particles
• CPC Class Codes: C10N 2020/063 : Fibrous forms
• CPC Class Codes: C10N 2030/02 : Pour-point; Viscosity index
• CPC Class Codes: C10N 2040/08 : Hydraulic fluids, e.g. brake-fluids
• CPC Class Codes: C10N 2050/015 : Dispersions of solid lubricants
• CPC Class Codes: C10N 2050/10 : Semi-solids; greasy

Abstract

The introduction of nanostructures in a liquid provides a means for changing the physical and/or chemical properties of the liquid. Improvements in heat transfer, electrical properties, viscosity, and lubricity can be realized upon dispersion of nanotubes in liquids. Stable dispersions of nanostructures are described and surfactants/dispersants are identified which can disperse nanostructures in petroleum liquid medium. The appropriate dispersant is chosen for the selected nanostructure material and the oil based medium and the dispersant is dissolved into the liquid medium to form a solution. The nanostructure is added to the dispersant containing the solution with agitation, ultrasonication, and/or combinations thereof. Nanostructures dispersed in a fluid form a nanofluid utilized as a shock absorber oil whereby the nanostructures serve to improve the viscosity index of the fluid or more particularly the shock absorber oil in the form of a lubricant additive.

Claims

1. A method of preparing a stable dispersion of carbon nano particles in a liquid, comprising the steps of:

dissolving a dispersant comprising a surfactant having a low hydrophile-lipophile balance (HLB) value of 8 or less in an amount of from 0.001 to 30.0 percent, into a major amount of a liquid medium selected from the group consisting of a mineral oil, a hydrogenated oil, a vegetable oil, a synthetic oil, and combinations thereof forming a dispersant liquid medium;

adding carbon nano material having an aspect ratio of from 500 to 5,000 in an amount of from 0.01 to 10.0 percent by weight into said dispersant liquid medium with mechanical agitation;

forming a uniform suspension of colloidal size solid particles; and

adding said uniform suspension of collidal size solid particles to a shock absorber fluid forming a nanofluid.

3. The method according to claim 1, including the step of adding a plasticizer.

4. The method according to claim 3, wherein said plasticizer is selected from the group consisting of a phthalate, an adipate, a sebacate ester, a glyceryl tri(acetoxystearate), an epoxidized soybean oil, an epoxidized linseed oil, a N,n-butyl benzene sulfonamide, an aliphatic polyurethane, a polyester glutarate, a triethylene glycol, a caprate/caprylate, a long chain alkyl ether, a dialkyl diester glutarate, a monomeric polymer, a polyester based on adipic acid, a hydrogenated dimer acid, a distilled dimer acid, a polymerized fatty acid trimer, an ethyl ester of hydrolyzed collagen, an isostearic acid, a sorbian oleate, a cocoyl hydrolyzed keratin, a lanolin oil, a dialkyl adipate, an alkylaryl phosphate, an alkyl diaryl phosphate, a modified triaryl phosphate, triaryl phosphate, a butyl benzyl phthalate, an octyl benzyl phthalate, analkyl benzyl phthalate, a dibutoxy ethoxy ethyl adipate, a 2-ethylhexyldiphenyl phosphate, a dibutoxy ethoxy ethyl formyl, a diisopropyl adipate, a diisopropyl sebacate, an isodecyl oleate, a neopentyl glycol dicaprate, a neopenty glycol diotanoate, an isohexyl neopentanoate, an ethoxylated lanolin, a polyoxyethylene cholesterol, a propoxylated (2 moles) lanolin alcohol, a propoxylated lanoline alcohol, an acetylated polyoxyethylene derivative of lanoline, a dimethylpolysiloxane, a glycerine, a polyethylene glycol, a dibutyl phthalate, a 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, a diisononyl phthalate, and combinations thereof.

2. A method of preparing a stable dispersion of carbon nano particles in a liquid, comprising the steps of:

dissolving a dispersant in an amount of from 0.001 to 30.0 percent comprising a surfactant having a low hydrophile-lipophile balance (HLB) value of 8 or less into a major amount of a liquid medium selected from the group consisting of a mineral oil, a hydrogenated oil, a vegetable oil, a synthetic oil, and combinations thereof forming a dispersant liquid medium;

adding carbon nano material having an aspect ratio of from 500 to 5000 in an amount of from 0.01 to 10.0 percent by weight into said dispersant liquid medium with ultrasonification;

forming a uniform suspension of colloidal size solid particles forming a uniform suspension of colloidal size solid particles; and

adding said uniform suspension of collidal size solid particles to a shock absorber fluid forming a nanofluid.