Electroless Plating of Iron onto Cellulose Fibers

We describe a new electroless iron bath capable of depositing a ferromagnetic FeB coating onto Pd/Sn-catalyzed substrates at room temperature without the need for an accompanying galvanic couple and illustrate its use for the fabrication of magnetic cellulose microfibers. The new electroless iron bath contains Fe²⁺ as the metal source, citrate as the metal chelator, boric acid buffer as the pH controller, and borohydride as the reductant. Surface analysis following plating confirms the deposition of an amorphous FeB coating of composition ∼Fe₁₀B onto the microfiber surface. Through the use of two-level factorial design statistical methods, we characterize the effects of plating variables (i.e., bath pH and concentrations of each bath component) on bath behavior, identifying pH as the sole factor influencing the mass of plated Fe and establishing optimal, reproducible conditions for electroless Fe deposition.