The influence of the solvent type on the rheological properties of Carbopol ® NF 980 dispersions in water and in water/glycerol solutions is investigated. The material formulation, preparation procedure, common experimental challenges and artifact sources are all addressed. Transient and steady-state experiments were performed. For both solvent types, a clearly thixotropic behavior occurs slightly above the yield stress, where the avalanche effect is observed. For larger stresses, thixotropy is always negligible. Among other findings, it is observed that, for a given Carbopol concentration, the dispersion in the more viscous solvent possesses a lower yield stress and moduli, a larger power-law index, and a longer time to reach steady state.

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This paper aims at studying the influence of different clay/coffee waste mixtures in structural ceramics by incorporating different amounts of spent coffee grounds as an additive. Clay paste with 5, 10, 15 and 20 wt-% of coffee waste was used to mould clay bodies, which were then fired at the temperatures of 900, 1000 and 1100uC. Morphological aspects were evaluated through SEM images, while several laboratory tests provide the physical and mechanical properties. Incorporation of coffee waste increases the water absorption and apparent porosity, and increasing the firing temperature causes an overall decrease in pore size. Samples with up to 10% coffee waste are in the highest grade of mechanical strength standards. The addition of 20% decreases by 70% the thermal conductivity value. The coffee waste residues could be used as a secondary clay raw material to form proper bricks with excellent thermal insulation proprieties.