Serum Separation Composition Thixotropy Stability
Solution Overview
Problem
Existing serum or plasma separating compositions face challenges in maintaining sufficient thixotropy without organic thixotropy enhancers, leading to crevice-like appearances in partition walls during centrifugation and potential contamination due to high hydrophilic inorganic powder ratios, which can cause water absorption and cloudiness.
Innovation Solution
A serum or plasma separating composition comprising a liquid resin component, hydrophilic and hydrophobic inorganic powders, and a polyalkylene glycol with a number average molecular weight of 500 to 100,000, used at a concentration of 0.2% to 5% by weight, along with water, to stabilize thixotropy and prevent crevice formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If inorganic powder concentration is increased to obtain sufficient initial yield stress, then thixotropy is improved, but the network of hydrogen bonding between inorganic powder particles is strengthened with time, causing the separating composition to lose fluidity during centrifugation
Solution Approach 1:
The patent changes the chemical composition parameters by introducing a specific organic compound (polyethylene glycol with molecular weight 10,000 to 100,000) at controlled concentrations (0.01-5% by weight). This parameter change modifies the hydrogen bonding network dynamics, allowing the composition to maintain adequate yield stress while preserving fluidity during centrifugation through controlled temporal evolution of bonding strength.
Solution Approach 2:
The patent creates a composite system combining inorganic powder particles with a specific organic compound (polyethylene glycol). This composite approach allows the organic compound to mediate the interactions between inorganic particles, providing both structural strength for thixotropy and controlled fluidity recovery during centrifugation, thus resolving the contradiction between initial strength and operational fluidity.
2Strength
If inorganic powder concentration is increased to improve thixotropy, then yield stress is improved, but phase separation occurs into island domains and sea domains, causing crevice formation in partition walls
Solution Approach 1:
The patent introduces polyethylene glycol as an intermediary substance between inorganic powder particles. This intermediary prevents direct particle-particle contact and aggregation, maintaining homogeneous distribution of inorganic particles throughout the liquid resin. The polyethylene glycol acts as a spacer that prevents phase separation into island and sea domains, thereby preventing crevice formation while maintaining adequate yield stress.
Solution Approach 2:
The patent modifies the compositional parameters by adding polyethylene glycol at specific concentrations (0.01-5% by weight), which changes the interaction parameters between inorganic particles. This parameter change prevents the formation of high-concentration inorganic domains by altering the dispersion stability, thus maintaining compositional homogeneity and preventing crevice formation in the partition wall structure.
3Strength
If organic thixotropy enhancers with water solubility are used to reduce inorganic powder concentration, then thixotropy is stabilized, but the enhancers elute into blood, damaging cell membranes and affecting test values
Solution Approach 1:
The patent uses polyethylene glycol with high molecular weight (10,000 to 100,000) which, while providing thixotropy enhancement, has reduced solubility and penetration capability compared to lower molecular weight variants. This allows the use of an organic compound that provides necessary thixotropic properties without the harmful elution effects, effectively replacing problematic water-soluble alternatives while maintaining thixotropy stability.
4Stability of the object's composition
If organic thixotropy enhancers are used to stabilize thixotropy, then yield stress stability is improved, but water absorption in the blood is promoted, making the separating composition cloudy
Solution Approach 1:
The patent changes the molecular weight parameter of the polyethylene glycol to a high range (10,000 to 100,000), which fundamentally alters the water absorption characteristics. High molecular weight polyethylene glycol has reduced hydrophilicity and water absorption capacity compared to lower molecular weight variants, thus maintaining thixotropy stability while preventing cloudiness formation in the separating composition.
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 composition maintains stable thixotropy over time, prevents crevice-like appearances in partition walls, and reduces the risk of contamination, ensuring accurate blood component separation and measurement.
Implementation Method 1
Compositions presently used as the serum or plasma separating compositions are those having thixotropy. Such a serum or plasma separating composition contained in a testing container can be prevented from moving during transportation or storage because it has thixotropy.
Implementation Method 2
a technique for separating serum or plasma from blood by centrifugation using a difference in specific gravity between blood components
Data Source
AI summary
The invention provides a serum or plasma separating composition which can compensate for the lack of initial thixotropy even at a reduced inorganic powder concentration and in which crevices or the like are less likely to be created in a partition wall formed of the separating composition after being centrifuged. The serum or plasma separating composition contains a liquid resin component having a partition wall-forming capability, a hydrophilic inorganic powder, a hydrophobic inorganic powder, and an organic compound serving as a thixotropy enhancer, wherein the organic compound is a polyalkylene glycol and/or a derivative thereof and is made of at least one type of polymer selected from the group consisting of: 1) a homopolymer of a single type of monomer selected from C3 to C5 alkylene oxide monomers; 2) a random copolymer, an altering copolymer, or a periodic copolymer of two or more types of monomers selected from C2 to C5 alkylene oxide monomers; 3) a block copolymer of two or more types of monomers selected from C3 to C5 alkylene oxide monomers; and 4) a graft copolymer of at least one type of polymer selected from the polymers 1) to 3), the polyalkylene glycol and/or the derivative thereof has a number average molecular weight of 500 to 100000, both inclusive, and the content of the polyalkylene glycol and/or the derivative thereof in the total amount of the serum or plasma separating composition is 0.2% to 5% by weight, both inclusive.