Plasma Feedstock Delivery with Independent Reagent Dosing
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Solution Overview
Problem
Current plasma treatment methods for particulate materials are limited in their ability to introduce specific surface chemistries, such as silane functionalization and metal decoration, due to the use of gaseous feedstocks and bubbler systems, which are inefficient and restrictive in terms of control and compatibility with non-volatile reagents.
Innovation Solution
A method and apparatus for plasma treatment that allows independent control of gaseous plasma forming feedstocks and liquid or solid reagents, enabling the use of non-volatile chemicals and metals, and eliminating the need for electrode deposition by direct injection of reagents into the treatment vessel, where they can be activated by the plasma.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If bubbler systems are used to deliver liquid reagents into plasma reactors, then volatile liquid reagents can be introduced, but the system cannot handle non-volatile liquids and solids, and control over reagent delivery is difficult
Solution Approach 1:
The patent changes the physical state parameter of reagent delivery by using aerosol generation to convert liquids and solids into fine particulate form that can be carried by gas flow into the plasma reactor, enabling delivery of non-volatile reagents that cannot be delivered by traditional bubbler systems
Solution Approach 2:
The patent introduces an intermediary aerosol generation system that converts liquid or solid reagents into a form suitable for gas-phase delivery, allowing independent control of reagent delivery rate through the aerosol generator while maintaining plasma stability
2Quantity of substance
If metal electrodes are used for metal decoration during plasma treatment, then metal can be deposited onto the sample, but the electrode degrades and plasma characteristics become unstable
Solution Approach 1:
The patent extracts the metal source from the electrode structure itself and delivers it separately as an aerosolized reagent, eliminating the degradation problem associated with sacrificial metal electrodes while maintaining metal deposition capability
Solution Approach 2:
The patent replaces the mechanical electrode-based metal delivery system with an aerosol-based delivery system, allowing precise control of metal reagent delivery without the mechanical degradation and plasma instability caused by electrode erosion
3Adaptability or versatility
If wet chemistry methods are used for surface functionalization, then diverse chemistries can be introduced, but the process requires toxic reagents, high temperatures, and copious washing
Solution Approach 1:
The patent uses phase transition from liquid/solid reagent to aerosol to gas-phase reaction in plasma, enabling surface functionalization without the harsh conditions and waste associated with wet chemistry methods
Solution Approach 2:
The patent converts the typically harmful high-energy plasma into a beneficial activation source that enables reagent reactions at low temperatures, eliminating the need for toxic reagents and high-temperature processing required by conventional wet chemistry
4Reliability
If gaseous plasma feedstocks are used for plasma treatment, then plasma can be maintained under controlled low-pressure conditions, but specific surface chemistries like silanes and metals are not readily accessible
Solution Approach 1:
The patent creates a composite plasma system combining gaseous plasma with aerosolized liquid or solid reagents, maintaining the benefits of controlled plasma while expanding accessible chemistries to include silanes, metals, and other non-volatile materials
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables precise control over surface functionalization, expands the range of accessible chemistries, and allows for the treatment of larger quantities and diverse materials, including non-conductive solids, with improved efficiency and reduced environmental impact.
Implementation Method 1
causing formation of a glow discharge plasma in the treatment vessel from the gaseous plasma forming feedstock
Implementation Method 2
contacting the sample with the glow discharge plasma and the reagent
Data Source
AI summary
The present application relates to methods and apparatus for delivering liquid or solid feedstocks into a plasma treatment vessel. More specifically, the invention provides a method for treating a sample using glow discharge plasma in an apparatus comprising a treatment vessel, the method comprising (i) delivering a gaseous plasma forming feedstock into the treatment vessel through a gas supply line under the control of a gas flow controller, and causing formation of a glow discharge plasma in the treatment vessel from the gaseous plasma forming feedstock; and simultaneously (ii) delivering a reagent into the treatment vessel under the control of a reagent dosing controller, wherein the reagent is a liquid or a solid; and (iii) contacting the sample with the glow discharge plasma and the reagent; wherein the gas flow controller and the reagent dosing controller allow independent control of the rate of delivery of the gaseous plasma forming feedstock and the reagent.