Week 4: Stage 2 Overview: From Flow to Structure

Why the course moves from measuring behaviour to explaining it, and how a network's connectivity — not just its ingredients — sets a gel's texture.

15 March 2027

Outline#

• Recap: Stage 1 gave us the language to describe what a material does (its modulus, its flow curve, its thermal signature) without yet asking why it does that. Stage 2 asks why.
• The common thread across Modules 4–6: each is a different route to the same outcome — a network or dispersed structure that resists flow. Starch gels network through crystallite junction zones, proteins network through covalent and physical aggregation, emulsions resist separation through droplet size and continuous-phase viscosity rather than a true network.
• Introducing percolation as a shared idea: a structure that only “sets” once enough connections exist to span the system, with a critical point (Module 5’s gel point) rather than a gradual thickening.
• Why this stage still leans on Stage 1’s tools: every claim about structure in Modules 4–6 is checked against a measurable consequence — modulus, gel time, creaming rate — not asserted from ingredient lists alone.
• What changes for the Laboratory Portfolio from this stage onward: model fitting starts to matter as much as reading a single measured value, in preparation for Stage 4.