Method of forming substrate carriers and articles from compositions comprising carbon nanotubes
View Patent ↗Substrate containers formed from improved compositions comprise a polymer and carbon nanotubes to provide enhanced characteristics. In some embodiments, the carbon fibers, e.g., nanotubes, can be mechanically blended or incorporated into the polymer, while in some embodiments carbon nanotubes also may be covalently bonded to the polymer to form corresponding covalent materials. In particular, the polymer can be covalently bonded to the side walls of the carbon nanotubes to form a composite with particularly desirable mechanical properties. The processing of the nanotubes can be facilitated by the dispersion of the nanotubes in an aqueous solution comprising a hydrophylic polymer, such as ethyl vinyl acetate. A dispersion of nanotubes can be combined with a polymer in an extrusion process to blend the materials under high shear, such as in an extruder.
1. A method of forming a substrate carrier, the method comprising the steps of:
preparing a liquid dispersion of carbon fibers, wherein the carbon fibers have side walls and ends and comprise single wall carbon nanotubes, multiple wall carbon nanotubes, or a combination thereof, the side walls of the carbon fibers, exclusive of the ends, being functionalized such that they comprise functional groups on an exterior of the side walls for covalently bonding with a thermoplastic polymer,
injecting the liquid dispersion of carbon fibers within an extruder having the thermoplastic polymer within the extruder, wherein the liquid dispersion of carbon fibers comprises an aqueous dispersion of carbon fibers and a stabilizer selected from a group consisting of ethyl vinyl acetate, poly(vinyl alcohol) and combinations thereof,
applying shear to blend the carbon fibers within the thermoplastic polymer and covalently bond the thermoplastic polymer to side walls of the carbon fiber to form a composite, wherein at least about 25 weight percent of the carbon fibers are covalently bonded to the thermoplastic polymer, and
injecting the composite into a mold for a substrate carrier component.
2. The method of claim 1 wherein the carbon fibers are present at a concentration of less than about 50 percent by weight.
3. The method of claim 1 wherein the carbon fibers are present at a concentration from about 0.1 percent by weight to about 40 percent by weight.
4. The method of claim 1 wherein the side walls of the carbon fibers are functionalized by being fluorinated for covalently bonding with the thermoplastic polymer.
5. The method of claim 1 , wherein the thermoplastic polymer is chosen from polybutylene terephthalate (PBT), polyolefins (PO), polyethylene terephthalate (PET), styrene block co-polymers, nylon in the form of polyether block polyamide (PEBA), polyetheretherketone (PEEK), poly(vinylidenefluoride), poly(tetrafluororethylene) (PTFE), polyethylene, polypropylene, poly(vinylchloride) (PVC), ethyl vinyl acetate and blends and copolymers thereof.
6. A method of forming a substrate carrier, the method comprising the steps of:
preparing a liquid dispersion of carbon fibers, wherein the carbon fibers have side walls and ends and comprise single wall carbon nanotubes, multiple wall carbon nanotubes, or a combination thereof, the side walls of the carbon fibers, exclusive of the ends, being functionalized such that they comprise functional groups on an exterior of the side walls for covalently bonding with a thermoplastic polymer, wherein the liquid dispersion of carbon fibers comprises an aqueous dispersion of carbon fibers and a stabilizer selected from a group consisting of ethyl vinyl acetate, poly(vinyl alcohol) and combinations thereof,
injecting the liquid dispersion of carbon fibers within an extruder having the thermoplastic polymer within the extruder,
applying shear to blend the carbon fibers within the thermoplastic polymer and covalently bond the thermoplastic polymer to the side walls of the carbon fiber to form a composite, wherein at least about 25 weight percent of the carbon fibers are covalently bonded to the thermoplastic polymer, and
feeding the composite from the extruder and apply a coating of the composite onto a surface of a substrate carrier.
7. The method of claim 6 wherein the carbon fibers are present at a concentration of less than about 50 percent by weight.
8. The method of claim 6 wherein the carbon fibers are present at a concentration from about 0.1 percent by weight to about 40 percent by weight.
9. The method of claim 6 wherein the side walls of the carbon fibers are functionalized by being fluorinated for covalently bonding with the thermoplastic polymer.
10. The method of claim 6 , wherein the thermoplastic polymer is chosen from polybutylene terephthalate (PBT), polyolefins (PO), polyethylene terephthalate (PET), styrene block co-polymers, nylon in the form of polyether block polyamide (PEBA), polyetheretherketone (PEEK), poly(vinylidenefluoride), poly(tetrafluororethylene) (PTFE), polyethylene, polypropylene, poly(vinylchloride) (PVC), ethyl vinyl acetate and blends and copolymers thereof.