Suspension Development for Green-Flame Propellant
To develop a practical green-flame hypergolic propellant, a suspension formulation was required to maintain metal oxide particles in liquid fuel. Laboratory work began evaluating surfactant systems and coating strategies for the target green-flame compounds. Initial small-batch synthesis showed promising suspension characteristics in benchtop tests.
Particle Agglomeration in Storage
Long-term storage testing revealed critical failures in particle suspension stability. After 2-3 weeks at room temperature, green-flame metal oxide particles began agglomerating into larger clumps. Settling occurred despite surfactant treatment, with 10-15% of particles depositing at tank bottom within 30 days. Centrifugal testing showed the agglomeration process accelerated under modest acceleration.
Surfactant Incompatibility Issues
Laboratory analysis identified the root cause: the selected surfactant system was chemically incompatible with the green-flame metal oxide compounds. The surfactant coating degraded through oxidation and hydrolysis, leading to particle coalescence. Alternative surfactants tested showed similar degradation patterns. The green-flame metal oxides appeared to catalyze surfactant decomposition, creating a fundamental chemical incompatibility.
Reformulation Efforts
New surfactant candidates from different chemical families are being evaluated. Laboratory synthesis of protective coatings using alternative materials is underway. Small-batch suspension testing continues with modified formulations. Current focus is on developing a stable suspension capable of 6-month storage without settling or particle agglomeration. Fundamental research into metal oxide surface chemistry is supporting these efforts.