A system, apparatus and method are provided for processing articles. The system includes subsystems for synthesizing, pre-treating, conducting a vapor phase coating process and post-treating articles in the form of powders and solid or porous workpieces. The apparatus permits vapor phase synthesis, treatment and deposition processes to be performed with high efficiency and at high overall throughput. The methods include converting solids, liquids or gases into gaseous and solid streams that can be separated or exchanged with or without treatment and/or coating steps, and produce optimized composite articles for specific applications.