摘要:
An optical sensor for monitoring an environmental condition, the optical sensor comprising a perfluorosulfonate ionomer membrane comprising a solution, wherein the solution comprises a transition metal-free dye component, wherein exposure of the optical sensor to a specific environmental condition produces a color shift on the optical sensor.
摘要:
A method for fabricating diffusion media for a fuel cell that includes using variable frequency microwaves for heating the diffusion media after it has been coated with a solvent including fluorocarbon particles to provide broader control over the distribution of the fluorocarbon on the diffusion media. In one embodiment, a carbon fiber substrate is dipped in a solution including the fluorocarbon particles and a surfactant. The wet and coated substrate is then dried using the microwave radiation, where the frequency of the microwave radiation is varied to increase or control the dispersion of the fluorocarbon particles and the hydrophobicity of the diffusion media. In one embodiment, the microwave radiation is varied in frequency between 500 MHz and 1000 GHZ.
摘要:
Embodiments of a coated substrate comprise a substrate (100) and a multi-layer multi-functional nanoparticle coating (105) having a thickness of up to about 500 nm thereon. The nanoparticle coating (105) comprises an ionic polyelectrolyte layer (110), and an ionic multi-colloid layer disposed over the polyelectrolyte layer (110). The multi-colloid layer comprises hydrophilic colloid ions (130) disposed over and coupled to the polyelectrolyte layer (110), conductive colloid ions (120) disposed over and coupled to the polyelectrolyte layer (110). The conductive colloid ions (120) are separated from the hydrophilic colloid ions (130) by repulsive forces therebetween.
摘要:
Provided are processes for preparing a thermodynamically stable PtBi2 alloy nanoparticle. In certain aspects, the process comprises preparing an aqueous mixture, with the aqueous mixture comprising: an inorganic compound comprising SnCl2; an inorganic compound comprising Bi; and HCl. The process further comprises adding PtCl4 to the mixture. The process results in the spontaneous reduction of Bi and Pt. Excess SnCl2 is adsorbed as a ligand at the surface of the PtB2 alloy nanoparticle, which serves to stabilize the nanoparticle. Another aspect provides a thermodynamically stable PtBi2 nanoparticle. The nanoparticle comprises a core comprising a PtBi2 alloy. The nanoparticle further comprises a shell at least partially encapsulating the core, with the shell comprising stannous chloride. The thermodynamically stable PtB2 nanoparticle has a negative charge.
摘要:
Embodiments of a coated substrate comprise a substrate (100) with a multi-functional multi-layer nanoparticle coating (105) having a thickness of up to about 500 nm thereon. The nanoparticle coating (105) comprises an ionic polyelectrolyte layer (110), and a mixed colloid layer disposed over the polyelectrolyte layer (110). The mixed colloid layer comprises hydrophilic colloid ions (130) and conductive colloid ions (120) which is coupled through electrostatic or non-electrostatic forces, and the conductive colloid ions (120), the hydrophilic colloid ions (130), or both are coupled to the polyelectrolyte layer (110).
摘要:
Favorable performance of diffusion media in fuel cells has found to be correlated to a parameter (the C/F ratio) that relates to a spatial and thickness distribution of the hydrophobic fluoropolymer on the carbon fiber substrate structure of the medium. Suitable diffusion media may be chosen from among commercially coated diffusion media by measuring the C/F ratio by means of energy dispersive spectroscopy, and choosing the diffusion media if the value of the C/F ratio is within the preferred range. Alternatively, the diffusion media may be manufactured with an improved process that consistently yields values of C/F ratio in the desired range.
摘要:
A process comprising: submerging a fuel cell bipolar plate in a bath comprising nanoparticles and a liquid phase comprising a nanoparticles dispersion agent and wherein the bipolar plate includes an upper surface having a plurality of lands and channels formed therein; removing the fuel cell bipolar plate from the bath so that a coating comprising nanoparticles adheres to the fuel cell bipolar plate; while the coating is wet and before the coating is dried and solidified, removing the coating comprising nanoparticles from the lands of the bipolar plate, leaving coating comprising nanoparticle in the channels; and drying the coating in the channels.
摘要:
Embodiments of a coated substrate comprise a substrate (100) with a multi-functional multi-layer nanoparticle coating (105) having a thickness of up to about 500 nm thereon. The nanoparticle coating (105) comprises an ionic polyelectrolyte layer (110), and a mixed colloid layer disposed over the polyelectrolyte layer (110). The mixed colloid layer comprises hydrophilic colloid ions (130) and conductive colloid ions (120) which is coupled through electrostatic or non-electrostatic forces, and the conductive colloid ions (120), the hydrophilic colloid ions (130), or both are coupled to the polyelectrolyte layer (110).