Composites for sound control applications

Abstract

A sound attenuating material includes a matrix, and a nanofiller, the material effectively reduces the level of low frequency sound incident thereon.

1 . A sound attenuating material comprising:
 a matrix;   a nanofiller having an average size of about 1 nm to about 50 μm;   the material comprising about 0.1-30.0 wt. % nanofiller, and wherein the material reduces the level of sound at low frequency ranges of up to about 1,000 Hz by at least about 5 dB.   
   
   
       2 . The material of  claim 1 , wherein the matrix comprises a polymer. 
   
   
       3 . The material of  claim 2 , wherein the polymer comprises: polystyrene, polyurethane, polyethylene, polypropylene, hydrogels, polyacrylates, polyarylenes, polycarbonates, polyureas, polycyanurates, epoxies, nylons, aramids, polyvinyl chloride, polymers of (meth) acrylic acid or the esters and/or salts of (meth) acrylic acid, polyesters, rubber, PTFE, silicone, mixtures of two or more of any of the foregoing, or copolymers comprising one or more of the monomers of the foregoing polymers. 
   
   
       4 . The material of  claim 2 , wherein the matrix comprises an open celled foam of polyurethane, polyimides, polycyanurates, or melamine. 
   
   
       5 . The material of  claim 2 , wherein the matrix comprises polystyrene. 
   
   
       6 . The material of  claim 2 , wherein the matrix comprises a hydrogel. 
   
   
       7 . The material of  claim 6 , wherein the hydrogel comprises polyvinyl alcohol, sodium polyacrylate, (meth)acrylate polymer, 2-hydroxyethylmethacrylate, or N-vinyl-pyrrolidone. 
   
   
       8 . The material of  claim 1 , further comprising a cross-linking agent. 
   
   
       9 . The material of  claim 8 , wherein a cross-linking agent comprises: ethylene glycol dimethacrylate or polyethylene glycol dimethacrylate. 
   
   
       10 . The material of  claim 1 , further comprising a photoinitiator, the photoinitiator comprises 2,2-dimethoxy-2-phenyl acetophenone. 
   
   
       11 . The material of  claim 1 , wherein the matrix comprises an aerogel. 
   
   
       12 . The material of  claim 1 , wherein the matrix comprises a nonwoven fibrous material. 
   
   
       13 . The material of  claim 1 , wherein the nanofiller comprises one or more of: nanopowders, nanotubes, nanofibers and nanoparticles. 
   
   
       14 . The material of  claim 13 , wherein the nanofiller comprises one or more of: carbon nanotubes, carbon nanopowders, graphite platelets, carbon nanofibers, hemp fibers, flax fibers, barium sulfate, silicon dioxide, silicon carbide, silicon nitride, aluminum oxide, aluminum nitride, titanium dioxide, titanium carbide, tin oxide, iron oxide, zinc oxide, magnesium oxide, magnesium hydroxide, zirconium oxide, cerium oxide, lithium oxide, silver oxide, a mixed metal oxide, silver, nickel, magnesium, zinc, montmorillonitey polyhedral oligomeric silsesquioxane, an aluminum alloy, a copper alloy, a gold alloy, an iron alloy, a nickel alloy, a platinum alloy, a silver alloy, a tantalum alloy, a tin alloy, a titanium alloy, and a zinc alloy. 
   
   
       15 . The material of  claim 1 , wherein the material comprises about 1.0-30.0 wt % nanofiller. 
   
   
       16 . The material of  claim 15 , wherein the material comprises about 15.0-30.0 wt % nanofiller. 
   
   
       17 . The material of  claim 1 , wherein the material comprises about 1.0-10.0 wt % nanofiller. 
   
   
       18 . The material of  claim 17 , wherein the material comprises about 1.0-5.0 wt % nanofiller. 
   
   
       19 . The material of  claim 15 , wherein the nanofiller comprises silver particles, and the material comprises about 15.0-30.0 wt % of the silver particles. 
   
   
       20 . The material of  claim 1 , wherein the nanofiller is modified by the inclusion of an organic functional group. 
   
   
       21 . The material of  claim 20 , wherein the organic functional group comprises: benzyl, hydroxyl, acetyl, phenyl, alkyoxy, alkyl, methyl, ethyl, propyl, substituted alkyls. 
   
   
       22 . The material of  claim 1 , wherein the nanofiller is modified by NaOH. 
   
   
       23 . The material of  claim 1 , wherein the nanofiller has an average size of about 10 nm-300 nm. 
   
   
       24 . The material of  claim 23 , wherein the nanofiller has an average size of about 10 nm-100 nm. 
   
   
       25 . The material of  claim 1 , wherein the material reduces the sound level by at least about 15 dB. 
   
   
       26 . The material of  claim 25 , wherein the material reduces the sound level by at least about 20 dB. 
   
   
       27 . The material of  claim 26 , wherein the material reduces the sound level by at least about 25 dB. 
   
   
       28 . The material of  claim 27 , wherein the material reduces the sound level by at least about 35 dB. 
   
   
       29 . The material of  claim 1 , wherein the material is in the form of a sheet or a layer having a thickness no greater than about 0.22 in. 
   
   
       30 . A sound barrier comprising the material of  claim 1 . 
   
   
       31 . A sound-emitting device comprising the sound barrier of  claim 30 . 
   
   
       32 . The material of  claim 1 , wherein the matrix comprises polyester.