Combustion synthesis of porous biomaterials

Abstract

This article discusses the unique material manufacturing process of self-propagating high temperature synthesis (SHS) as applied to the making of porous biomaterials. Porous materials have long been considered as the first step toward in-vivo bone tissue engineering and the creation of patient life-time implants. The authors have approached this challenge by utilizing combustion synthesis, to create novel materials such as NiTi + TiC as well as porous forms of materials that are commonly accepted for biomedical applications such as tricalcium phosphate and hydroxyapatite. In the SHS product, physico-chemical properties are controlled by, but not limited to, reactant stoichiometry; green density; particle size of the reactant mix; use or presence of a gasifying agent; heating rate of the reactants and gravity. By balancing these parameters, the energy of the reaction is controlled to create the desired product stoichiometry, porosity, and mechanical properties. SHS provides a means to rapidly manufacture materials, saving time and production costs as well as enabling the synthesis of custom devices through the use of individual molds. Mold materials can range from graphite to paper or paper machete. Combustion synthesis offers a method for the rapid manufacture of affordable, individual biomedical devices that will reduce patient recovery time.

Biologic potential of calcium phosphate biopowders produced via decomposition combustion synthesis

“…There appears to be no obvious uniform particle geometry that would indicate sintering of the reactants. Product morphology is indicative of a SHS reaction [2, 7, 52]. …”

“…Traditional combustion synthesis methods utilize solid-state reactions of reactant powders [2] whereas decomposition combustion synthesis (DCS) requires the aqueous decomposition and subsequent reconstitution of the reactants into a gelatinous foam prior to ignition [3, 4]. Calcium phosphate DCS is a self-propagating high-temperature synthesis (SHS) process that utilizes the heat generated by the exothermic reaction of urea, calcium nitrate and ammonium phosphate to generate and sustain the propagation of a combustion wave [5–7] through the reactants.…”

Combustion Synthesis: An Update

“…Ayers et al combustion synthesized materials of importance in the biomedical fi eld. They used CaO and P 2 O 5 powders to synthesize calcium triphosphate, Ca 3 (PO 4 ) 2 , in reduced gravity [63] . They concluded that grains displayed a spherical morphology in comparison to the longitudinal -radial shape observed at terrestrial gravity.…”

Self-propagating high-temperature synthesis of nanostructured titanium aluminide alloys with varying porosity

“…This strategy was shown to be highly successful for synthesizing ceramic materials for biological applications [2]. Incorporating blowing agents to synthesis metal alloys has not been widely pursued, yet has recently been shown to be feasible using nanoparticles [3].…”