Solar receiver coating development: the synthesis and growth of copper chromite spinel particles across sol-gel routes and calcination profiles

CuCr2O4 is a promising spectrally selective material for solar receiver coatings to improve solar efficiency. Key requirements of such a coating are its high absorptivity, robustness, and ability to prevent high temperature oxidation of the substrate. This work describes synthesis routes for the creation of CuCr2O4 particles that exhibit adequate sinterability for developing robust solar receiver coatings that can prevent oxidation. The Pechini and modified Pechini sol-gel methods were directly compared as two routes for nanoparticle creation. Particle growth was studied by heating the nanoparticles at different temperatures (650°C, 750°C, 850°C) and times (between 1 h and 24 h) and measuring the particle sizes via laser diffraction and scanning electron microscopy. Phase identification was determined by powder X-ray diffraction. The kinetics of particle growth observed were consistent with a diffusion limited inhibited grain growth mechanism. The sol-gel route synthesized through modified Pechini and calcined at 650°C for 3h produced the smallest (84nm) single-phase spinel particles. The modified Pechini method displayed evidence of greater agglomeration and produced smaller particles than the Pechini method. Pellets were formed to evaluate the effectiveness of the sol-gel derived nanoparticles for improving sinterability. It was demonstrated that CuCr2O4 powders of larger starting particle sizes exhibit low sinterability and do not form coatings capable of preventing high temperature oxidation of the underlying substrates.

Name thesis:degree_name

Master of Science (M.S.)

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Metallurgical and Materials Engineering

Grantor dc:publisher

Colorado School of Mines. Arthur Lakes Library

Year dc:date.issued

2023

Author dc:creator

• Billman, Julia E.

Advisor dc:contributor.advisor

• Reimanis, Ivar E. (Ivar Edmund)

Committee members dc:contributor.committeemember

• Packard, Corinne E.
• Brennecka, Geoffrey

• agglomeration
• copper chromite
• particle growth
• Pechini
• sol-gel

Statement dc:rights

• Copyright of the original work is retained by the author.

Language dc:language.iso

eng, English

Identifier

T 9566

OAI identifier oai:identifier

oai:repository.mines.edu:11124/178511