About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Molecular Approaches to Ceramics; Synthesis, Processing, Modeling, and Derived Ceramics
|
| Presentation Title |
Lignin-Silicon Hybrid Ceramic Structures: Chemically Active versus Passive Colloids in Preceramic Sol-Gel Systems |
| Author(s) |
Roo Walker, Jacob Feldbauer, Dustin Gilmer |
| On-Site Speaker (Planned) |
Roo Walker |
| Abstract Scope |
The utilization of biopolymer-derived ceramic precursors into sol-gel systems is complicated by particle sedimentation during gelation, producing compositionally inhomogeneous structures. This study compares two colloidal approaches using (3-aminopropyl)triethoxysilane (APTES) modified kraft lignin (SAL) in ethanol/tetraethyl orthosilicate (TEOS)/citric acid sols. Unpyrolyzed SAL retains ethoxysilane surface functionality expected to participate in co-condensation with TEOS during gelation. Pre-pyrolyzed SAL (pSAL) has undergone ceramic conversion and no longer presents reactive silane groups. The two systems differ in particle density, surface chemistry, and potential for interaction with the developing network. Polyvinylpyrrolidone (PVP) is evaluated as a stabilizer to determine the minimum loading required for homogenization. Sedimentation behaviors are compared against Stokes predictions from measured particle size distributions and densities. Compositional homogeneity is assessed by SEM/EDS on sectioned samples. Pyrolyzed composites are characterized for ceramic yield and microstructure. |