Antimicrobial Phosphate Glass Refractive Index Control
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Solution Overview
Problem
Existing antimicrobial glass compositions face issues with low hydrolytic resistance, water solubility, and compatibility with polymers, leading to unwanted discoloration and mechanical degradation, particularly in applications requiring high chemical resistance and transparency.
Innovation Solution
Development of antimicrobial glass compositions with specific oxide content ranges, including P2O5, B2O3, SiO2, Al2O3, and metal oxides, which provide high chemical resistance, adjustability of refractive index, and prevention of silver reduction, ensuring transparency and compatibility with polymers like polycarbonates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high concentrations of alkali oxides (Na2O, K2O) are used to achieve antimicrobial activity, then the reactivity and ion release capability improve, but the hydrolytic resistance deteriorates and complete water solubility occurs
Solution Approach 1:
The patent changes the chemical composition parameters by strictly limiting alkali oxide content to ≤0.1 wt% each (Na2O, K2O, Li2O) while adjusting the ratio of alkaline earth oxides (CaO, SrO, BaO) to maintain ion release capability. This parameter optimization resolves the contradiction by achieving antimicrobial effectiveness through controlled ion release without excessive water solubility.
Solution Approach 2:
The patent creates a composite glass system combining phosphate (P2O5 >45 wt%), borate (B2O3 0-60 wt%), and silicate (SiO2 0-40 wt%) networks with controlled alkaline earth oxide additions. This composite structure provides both the required chemical resistance and controlled reactivity for antimicrobial action, resolving the contradiction between stability and ion release.
2Illumination intensity
If TiO2 is added to adjust refractive index for polymer compatibility, then transparency improves, but UV absorption increases causing polymer discoloration and embrittlement
Solution Approach 1:
The patent optimizes TiO2 content to a precise range (0.01-10 wt%) and balances it with other refractive index modifiers (ZrO2, Nb2O3, La2O3) to achieve the desired refractive index match with polymers while minimizing UV absorption. This controlled parameter adjustment maintains transparency without causing harmful polymer degradation.
Solution Approach 2:
The patent introduces alternative refractive index modifiers (ZrO2, Nb2O3, La2O3) as intermediary substances that can adjust the refractive index with less impact on UV stability compared to high TiO2 content. These intermediaries provide the same optical function with reduced harmful effects on polymer materials.
3Ease of manufacture
If alkali oxides are used in glass compositions for polymer applications, then processing ease improves, but polymer chain rupture occurs leading to mechanical degradation
Solution Approach 1:
The patent extracts and removes alkali oxides (Na2O, K2O, Li2O) from the glass composition, limiting each to ≤0.1 wt%. This extraction eliminates the harmful interaction with polymer chains that causes embrittlement, while the patent maintains processability through optimized alkaline earth oxide content and glass composition design.
Solution Approach 2:
The patent changes the base composition parameters by using high P2O5 (>45 wt%) and B2O3 (0-60 wt%) content to maintain glass workability and processing ease without relying on alkali oxides. This parameter shift allows easy manufacturing while preserving polymer mechanical integrity.
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 glass compositions exhibit strong antimicrobial activity, high chemical resistance, and transparency, preventing discoloration and mechanical degradation, while maintaining environmental and health safety standards, suitable for various applications including cosmetics, medicine, and polymer preservation.
Implementation Method 1
The biocidal or biostatic action of the glass, the glass ceramics, the glass powder or the glass ceramic powder is caused by ion exchange or ion release, which is associated with a surface reaction, and a liberation of metal ions.
Implementation Method 2
ion exchange or ion release, which is associated with a surface reaction, and a liberation of metal ions
Implementation Method 3
it being possible to adjust the refractive index of the glass composition in order to make possible substances, particularly polymers, that are as transparent as possible
Implementation Method 4
the sum formed from Ag2O+ZnO+CuO+Cr2O3+I—+TeO2 and GeO2 lies in the range of 0.1-40 wt %
Data Source
AI summary
The invention provides an antimicrobial phosphate glass composition including, in weight percent based on oxide: greater than 45 to 90 of P2O5, 0 to 60 of B2O3, 0 to 40 of SiO2, 0 to 20 weight percent of Al2O3, 0 to 30 of SO3, 0 to 0.1 of Li2O, 0 to 0.1 of Na2O, 0 to 0.1 of K2O, 0 to 40 of CaO, 0 to 40 of MgO, 0 to 15 of SrO, 0 to 40 of BaO, 0 to 40 of ZnO, 0 to 5 of Ag2O, 0 to 15 of CuO, 0 to 10 of Cr2O3, 0 to 10 of I—, 0 to 10 of TeO2, 0 to 10 of GeO2, 0 to 10 of TiO2, 0 to 10 of ZrO2, 0 to 10 of La2O3, 0 to 5 of Nb2O3, 0 to 5 of CeO2, 0 to 5 of Fe2O3, 0 to 5 of WO3, 0 to 5 of Bi2O3, and 0 to 5 of MoO3.