Barrier coatings to minimize pesticide-surface interactions and contamination

Overview

This solution addresses pesticide contamination and loss caused by chemical interactions between pesticide formulations and the internal surfaces of containers, pipes, and handling equipment. By applying chemically inert barrier coatings, pesticide residues are less likely to adhere to or react with surfaces, reducing contamination, simplifying cleanup, and preserving product integrity. Two coating chemistries are proposed: Polydimethylsiloxane (PDMS) and Parylene C. Both are chemically inert, pinhole-free, and can be applied to arbitrarily shaped geometries, including complex internal surfaces, making them well suited for agricultural and industrial fluid handling systems.

Technical specifications

Coating options:

• PDMS: Applied by dissolving in hexane and using dip, spray, or flow coating techniques developed in-house, followed by curing. Adheres to a wide range of substrates and conforms to complex geometries.
• Parylene C: Applied via chemical vapor deposition (CVD), producing a uniform, conformal film with excellent adhesion to polymeric substrates.

Key features:

• Chemically inert to organic acid derivatives commonly found in pesticide formulations
• Pinhole-free and conformal coverage on internal and external surfaces
• Applicable to arbitrarily shaped geometries and various polymeric substrates
• Validated durability through Taber abrasion testing, ASTM G85-A3 acidified salt spray corrosion testing, and continuous seawater flow corrosion tests
• Surface integrity confirmed via SEM imaging and contact angle measurements, with minimal delamination or shear effects observed after extended exposure

Technology readiness level

The coatings have been validated in laboratory settings for moisture exposure, weathering, abrasion, and corrosion durability, with SEM and contact angle characterization confirming retention of pinhole-free, conformal surface characteristics. The next stage of validation will involve side-by-side fabrication and testing of PDMS and Parylene C samples applied to polymeric substrates representative of industry containers and pipes. Samples will undergo extended-duration immersion and agitation tests in pesticides, with pre- and post-exposure characterization using XPS, EDS, focused ion beam cross-section milling, SEM, and EIS analysis to assess chemical and physical integrity. An economic analysis comparing these coatings to current alternatives will be conducted to evaluate commercial viability.