Antimicrobial Coating Composition with Doped Semiconductor Shell
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Solution Overview
Problem
Current antimicrobial coatings are ineffective in controlling the release of silver ions and have limited photocatalytic activity, especially under visible light, making them insufficient for broad-spectrum microbial degradation in public and healthcare settings.
Innovation Solution
A nanoparticle composite with a silver nanoparticle core and a doped titanium oxide shell, enhanced by the inclusion of gold nanoparticles, which controls the release of silver ions and improves photocatalytic activity across a broader light spectrum through surface plasmon resonance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a silver nanoparticle core is used for antimicrobial action, then antimicrobial efficacy is improved, but stability and control of silver ion release deteriorate
Solution Approach 1:
The silver nanoparticle core is nested within a semiconductor shell, creating a core-shell structure where the inner silver core provides antimicrobial activity while the outer shell protects and stabilizes the core, controlling the release of silver ions into the environment
Solution Approach 2:
The invention combines silver nanoparticles with a semiconductor shell material to create a composite nanoparticle structure that integrates the antimicrobial properties of silver with the stabilizing and photocatalytic properties of the semiconductor shell
2Reliability
If TiO2 is used as photocatalyst, then photocatalytic action is improved, but effectiveness under visible light deteriorates due to wide band gap
Solution Approach 1:
The invention modifies the electronic structure parameters of TiO2 by introducing dopant atoms that create intermediate energy levels within the band gap, enabling the material to absorb visible light photons with lower energy than the original band gap requirement
Solution Approach 2:
The dopant atoms are incorporated at specific lattice sites within the TiO2 crystal structure, creating localized regions with modified electronic properties that facilitate visible light absorption while maintaining the overall photocatalytic functionality
3Stability of the object's composition
If semiconductor shell is added to control silver ion release, then stability is improved, but photocatalytic activity under visible light deteriorates
Solution Approach 1:
The semiconductor shell is engineered as a doped composite material that simultaneously provides structural stabilization of the silver core and maintains enhanced photocatalytic activity through visible light absorption enabled by the dopant-induced energy levels
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
The composite exhibits enhanced antimicrobial efficacy and stability, effectively degrading organic compounds and microbes under both UV and visible light, with improved silver ion control and photocatalytic efficiency.
Implementation Method 1
The core comprises a silver nanoparticle having an antimicrobial action
Implementation Method 2
The photocatalytic method is built on the reactive properties of electron-hole pairs generated in semiconductor particles under illumination by light whose energy is greater than the semiconductor band gap
Implementation Method 3
e-hv>3.2eV of the TiO2 photocatalyst leads to band gap excitation resulting in charge separation of electrons in the CB and holes in the VB
Implementation Method 4
the nanoparticle composite comprises a nanoparticle of a noble metal providing surface plasmon under the presence of electromagnetic radiation
Implementation Method 5
the at least one shell is formed by a doped semiconductor providing a photocatalytic action and increasing the stability of silver nanoparticle core by controlling the releasing of Ag ions
Implementation Method 6
The performance of a photocatalyst is improved by depositing or incorporating metal ion or non-metal dopants into the TiO2. Doping techniques are applied in photocatalysis to overcome limitations of TiO2 such as wide-band gap, ineffectiveness of photocatalysis under visible light
Implementation Method 7
Dopants create a charge space carrier region on the surface of TiO2 and prohibits the recombination of the photogenerated electron-hole pairs
Implementation Method 8
The photocatalytic action generates, in presence of light, oxidation-reduction power and act on organic compound and/or microbial cells in the vicinity
Data Source
Figure 1
AI summary
An antimicrobial coating composition comprising a nanoparticle composite having a core and at least one shell, wherein the core comprises a silver nanoparticle having an antimicrobial action. The at least one shell is formed by a doped semiconductor providing a photocatalytic action and increasing the stability of silver nanoparticle core by controlling the releasing of Ag ions. The nanoparticle composite comprises a nanoparticle of a noble metal providing surface plasmon under the presence of electromagnetic radiation.