Abstract: The present invention relates to a novel process for the remote plasma surface treatment of substrate particles at atmospheric pressure. The invention is motivated by the urge to overcome major drawbacks of particle treatment in low pressure plasmas and in-situ particle treatment at atmospheric pressure. The former requires complex and mostly expensive vacuum installations and vacuum locks usually prohibiting continuous processing. Independent of the system pressure, in-situ plasma treatment causes particle charging and therefore undesirable interaction with the electric field of the discharge, which is seen to contribute to the process of reactor clogging. Additionally, the filamentary discharges modes of atmospheric pressure plasmas are inflicted with inhomogeneous surface treatment. Furthermore, short radical lifetimes at elevated pressures complicate a remote plasma treatment approach as widely used in low pressure applications.

Abstract: The present invention relates to a novel process for the remote plasma surface treatment of substrate particles at atmospheric pressure. The invention is motivated by the urge to overcome major drawbacks of particle treatment in low pressure plasmas and in-situ particle treatment at atmospheric pressure. The former requires complex and mostly expensive vacuum installations and vacuum locks usually prohibiting continuous processing. Independent of the system pressure, in-situ plasma treatment causes particle charging and therefore undesirable interaction with the electric field of the discharge, which is seen to contribute to the process of reactor clogging. Additionally, the filamentary discharges modes of atmospheric pressure plasmas are inflicted with inhomogeneous surface treatment. Furthermore, short radical lifetimes at elevated pressures complicate a remote plasma treatment approach as widely used in low pressure applications.