Virginia Commonwealth University

Sentor Technologies, Inc.

Gary C Tepper

Dmitry Pestov

Royal Kessick

Gary E Wnek

Natalia Levit

Michael P Eddy

Brandon Dodd

Gilbert Annohene

Crystallization of perovskite films was performed in supercritical carbon dioxide with and without organic co-solvents. Post deposition crystallization of the films was performed in a binary, single phase supercritical fluid at constant conditions (45° C., 1200 psi) but with varying organic co-solvent volume fractions up to 2%. The co-solvents can provide selective interactions with one or both of the perovskite precursor compounds resulting in different film morphologies ranging from uniform films containing large grains to films exhibiting large cubic or hexagonal crystals or preferential crystallographic orientations. The use of supercritical fluids to enhance or tune crystallization in solid-state thin films could have broad applications toward the realization of high efficiency photovoltaic devices.

Low temperature formation of perovskite films in supercritical fluids

Methods and devices to rapidly detect trace levels of water soluble fluorescent mineral species such as uranium in aqueous fluids (e.g. water) are provided. The methods and devices involve sequestration of cationic forms of the water soluble fluorescent mineral species (e.g. the uranium oxycation uranyl, UO) via pressurized fluid flow through a porous silica gel medium, to enhance natural fluorescence and increase the speed of detection.

Method and apparatus for measuring trace levels of fluorescent minerals in water

A contaminant extraction apparatus, systems and method for extracting contaminants, such as particles and polar molecules, from an air flow containing a contaminated gas such as air so that the contaminants are expelled from the embodiments after they are extracted. One method includes the steps of generating two electric fields in separate air flow channels separated by an extraction grid with the second electric field having a greater potential difference than the first electric field; generating a first air flow through the first air flow channel and a second air flow through a second air flow channel; dispensing charged liquid droplets into the first air flow using at least one charged droplet generator; allowing the droplets to transfer charge to those contaminants; and expelling the contaminants into the second air flow using the potential difference in the second electric field.

Contaminant extraction systems, methods and apparatuses

Apparatuses, systems and methods for generating, dispersing and delivering chemical compounds utilizing desorption electrospray ionization. Embodiments include an airflow channel into which an airflow is directed, a solvent reservoir containing a volume of solvent, at least one charged droplet source for producing a plurality of charged liquid droplets in the channel, and at least one grounded counter electrode positioned within the channel with the electrodes having at least one surface containing one or more chemical compounds that include releasable ions. In operation, the charged droplets are directed onto the surface or surfaces so that the impact of the charged particles on said surface produces gaseous ions of at least one chemical compound on said surface, after which the gaseous ions are dispersed into the airflow.

Methods, systems and apparatuses for chemical compound generation, dispersion and delivery utilizing desorption electrospray ionization

An improved system for removing particles and contaminants from an air flow attract particles and contaminants to a plurality of charged spray droplets. The system has a first channel with an inlet and an outlet into which a first air flow is directed, an air flow containing a plurality of contaminants, a solvent reservoir containing a volume of solvent, one or more charged droplet sources for producing a plurality of charged liquid droplets, a second channel with an inlet and an outlet into which a second air flow is directed, one or more voltage reduction electrodes positioned about at least one of said electrospray sources, a grounded counter electrode, and at least one grid positioned between the plane of the charged droplet source and the grounded counter electrode. The voltage between the grid electrode and the charged droplet source is sufficient to sustain an electrospray process. The electrostatic force at the one or more charged droplet sources is sufficient to overcome the surface tension of the solvent. The charged liquid droplets are dispersed into the first channel allowing the plurality of contaminants in the first air flow to become charged.

Contaminant extraction systems, methods, and apparatuses

Small particles of polymeric material are produced by expansion of a mixture of monomers and a propellant. The size and shape of the particles can be precisely tailored by materials selection and expansion conditions. Particles of 10 nanometers to 100 microns can be produced. If monomers exhibiting solid state reactivity are utilized, the particles thus formed can be polymerized at any time after formation. The particles produced by this method can be molecularly imprinted by incorporating a template into the particle prior to fully curing the particle, in a manner which allows selective extraction of the template from the cured particle after formation without deformation of the imprint site. A two step polymerization process allows the particles to be deposited on and adhered to a wide variety of substrates without additional agents. The molecularly imprinted particles can be used in a wide variety of applications including the selective binding of analyte from a sample, where the analyte is the same as the template or is of substantially the same size and has a similar arrangement of chemical functional groups. Imprinted molecularly imprinted particles can be used for targeted delivery of agents in biological applications. Non-imprinted particles formed by the expansion technique using monomers of solid state reactivity can be used in optical data storage systems.

Molecular imprinting of small particles, and production of small particles from solid state reactants

Polymer fiber interconnects are produced between microscale features on substrate using only electrostatic forces. In one embodiment, electric field driven directed growth of fibers is achieved between microscale droplets of a concentrated polymer solution deposited on a substrate associated with a capacitor, such as an interdigitated capacitor. After depositing the droplets, the droplets on or near the positive electrode become positively charged and the droplets on or near the negative electode become negatively charged. Fibers form between the positively and negatively charged droplets due to electrostatic forces. In a second embodiment, positively charged and negatively droplets are created by electrospraying or by other means, and the fibers spontaneously form between droplets of opposite polarity. The process is similar to conventional electrospinning, but is achieved on a micrscopic scale and utilizes significantly lower driving potentials.

Growing community of inventors

Glen Allen, VA, United States of America

Gary C Tepper