Nonionic Surfactant Coating for Aqueous Drop Retraction

The patent introduces a nonionic surfactant mixture as an intermediary substance between the aqueous dispersion and the hydrophobic surface. The surfactant molecules have hydrophilic heads that interact with water and hydrophobic tails that interact with the hydrophobic surface, mediating the interaction and preventing drop retraction while maintaining deposition efficiency.

The patent changes the surface tension parameter of the aqueous dispersion by adding surfactants. This parameter change allows the dispersion to spread and adhere to hydrophobic surfaces without retracting, thereby preventing substance loss while maintaining efficient deposition.

The patent applies local quality by treating only the surface layer of the medical device with hydrophilic coating while maintaining the bulk hydrophobic properties. This allows the surface to be hydrophilic (improving lubricity and ease of insertion) while the bulk material retains its hydrophobic functionality.

The patent creates a composite structure with a hydrophobic bulk material and a hydrophilic surface coating. This composite approach allows the device to exhibit both hydrophobic functionality in its core and hydrophilic surface properties for improved insertion and reduced water retention issues.

The patent optimizes the surfactant concentration parameter to achieve the minimum effective amount needed to prevent drop retraction. By carefully controlling this parameter, the patent achieves high deposition efficiency while maintaining low solution viscosity and minimizing costs.

The patent uses synergistic interactions between different surfactant molecules to achieve enhanced performance at lower concentrations. The combined effect of multiple surfactants provides superior deposition efficiency compared to individual surfactants at equivalent total concentrations, reducing the need for high surfactant amounts.