Microporous Material for Controlled Volatile Release
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Solution Overview
Problem
Existing microporous materials used in volatile material delivery devices often suffer from uncontrolled volatile material transfer rates, leading to either inadequate fragrance release or excessive depletion, and are prone to forming liquid volatile material on the exterior surface, causing staining and uneven release.
Innovation Solution
A microporous material comprising a matrix of thermoplastic organic polymer, finely divided particulate filler, and a network of interconnecting pores, with a density of at least 0.8 g/cm3, a controlled volatile material transfer rate of 0.04 to 0.6 mg/(hour*cm2), and coatings on the surfaces to prevent liquid formation on the vapor release surface, maintaining the transfer rate with minimal increase up to 150% when temperature rises from 25° C to 60° C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the vapor permeable membrane is made more porous to increase volatile material release rate, then fragrance intensity is improved, but liquid volatile material forms on the exterior surface causing staining and uneven release
Solution Approach 1:
The patent applies local quality by creating different surface properties on the interior and exterior surfaces of the microporous membrane. The interior surface has properties optimized for volatile material uptake from the reservoir, while the exterior surface has properties optimized for controlled vapor release without liquid accumulation. This differential surface treatment prevents liquid volatile material formation on the exterior while maintaining high release rates.
Solution Approach 2:
The patent changes physical and chemical parameters of the microporous membrane by controlling the size, distribution, and connectivity of pores, as well as the surface energy and hydrophobicity characteristics. By adjusting parameters such as pore diameter (0.01-100 micrometers), porosity (30-90%), and surface hydrophobicity, the membrane achieves controlled volatile material transfer without liquid formation on the exterior surface.
2Productivity
If the vapor permeable membrane allows higher volatile material transfer rate, then fragrance intensity is improved, but the reservoir depletes too quickly
Solution Approach 1:
The patent implements feedback control through the design of the microporous membrane structure that automatically regulates volatile material transfer rates. The membrane's porosity and pore configuration provide inherent feedback mechanisms that prevent excessive depletion by maintaining equilibrium between volatile material uptake and release, ensuring sustained fragrance delivery over extended periods.
Solution Approach 2:
The patent controls the volatile material transfer rate by precisely adjusting membrane parameters including porosity (30-90%), pore size distribution (0.01-100 micrometers), and thickness. These parameter optimizations enable the membrane to maintain moderate, sustained release rates that prevent rapid reservoir depletion while ensuring adequate fragrance intensity throughout the product lifespan.
3Productivity
If the vapor permeable membrane is used in high temperature environments, then volatile material release rate increases, but the rate becomes uncontrolled and excessive
Solution Approach 1:
The patent modifies the physical and chemical parameters of the microporous membrane to reduce temperature sensitivity. By selecting polymers with appropriate glass transition temperatures, adjusting pore size distributions, and controlling surface hydrophobicity, the membrane maintains stable volatile material transfer rates across a range of temperatures from -40°C to 100°C, preventing excessive rate increases in hot environments.
Solution Approach 2:
The patent employs composite material structures combining multiple polymers or polymer blends with complementary thermal properties. This composite approach creates a membrane that exhibits reduced thermal expansion and stable pore structure at elevated temperatures, thereby maintaining consistent volatile material release rates even in high temperature environments such as automobile passenger compartments.
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 solution ensures consistent and controlled release of volatile materials, preventing liquid formation on the exterior surface, thus maintaining fragrance intensity and preventing staining, while maintaining a stable transfer rate across varying temperatures.
Implementation Method 1
Volatile material within the reservoir passes through the vapor permeable membrane and is released into the atmosphere
Implementation Method 2
The microporous material includes thermoplastic organic polymer, particulate filler, and a network of interconnecting pores
Data Source
AI summary
Microporous materials that include thermoplastic organic polyolefin polymer (e.g., ultrahigh molecular weight polyolefin, such as polyethylene), particulate filler (e.g., precipitated silica), and a network of interconnecting pores, are described. The microporous materials of the present invention possess controlled volatile material transfer properties. The microporous materials can have a density of at least 0.8 g/cm3; and a volatile material transfer rate, from the volatile material contact surface to the vapor release surface of the microporous material, of from 0.04 to 0.6 mg/(hour*cm2). In addition, when volatile material is transferred from the volatile material contact surface to the vapor release surface, the vapor release surface is substantially free of volatile material in liquid form.