Introductory description

This module will explore how Polymer Colloids are made and behave from a chemical engineering perspective.

Module web page

Module aims

Outline syllabus

This is an indicative module outline only to give an indication of the sort of topics that may be covered. Actual sessions held may differ.

The module will give students a solid understanding of several fundamental and contemporary aspects of polymer colloid science.

The module is divided into THREE key learning blocks.

BLOCK 1: INTRODUCTION TO COLLOIDS & SYNTHESIS OF POLYMER COLLOIDS BY (MINI-)EMULSION POLYMERIZATION

In this block we will discuss:

Introduction to colloids: what is a colloid? Phases and colloidal systems. Specific properties. Ancient colloids. The importance of surface area. Capillarity. Laplace pressure. Variety of shapes. Lyophilic vs. lyophobic colloids. Emulsion polymerization: what is an emulsion polymerization and how does it differ from a suspension polymerization, dispersion polymerization, precipitation polymerization, and miniemulsion polymerization? A brief history of emulsion polymerization. Pro’s and con’s of emulsion polymerization vs. bulk/solution polymerization. A typical recipe. Mechanistic understanding of Emulsion Polymerization: rate of polymerization, particle formation (micellar and homogeneous nucleation), particle growth, particle swelling, diffusion limitation/starved conditions, compartmentalization, zero-one vs. pseudo bulk polymerization kinetics, Trommsdorf effect. Miniemulsion polymerization: What is miniemulsion polymerization? Ostwald ripening, how to retard/arrest Ostwald ripening.

BLOCK 2: ON COLLOID MOTION AND RHEOLOGY In this block we will discuss

Motion of colloids: gravity, buoyancy, drag force (Newton/Rayleigh/Stokes), terminal velocity, Brownian motion, Osmotic pressure, Stokes Einstein (Smoluchowski/Langevin), Barometric height, Ballistic velocity, Propulsion on the microscale (Purcell). Kinetics of coagulation Rheology: We will (re-) introduce rheological concepts and apply these to colloidal dispersions. Key words: kinematics and dynamics, shear rate, stress, viscosity. Yield stress, visco-elasticity, shear thinning and thickening. Hydrodynamic effects. Brownian contributions. Flocculation and thixotropy (Reversible time effects).

BLOCK 3: COLLOID STABILITY Colloidal stability: How to prolong the lifetime of a lyophobic colloid. Electrostatic stabilization. DLVO theory. Steric stabilization. Bridging and depletion flocculation. After recapping ways to stabilize colloids via electrostatic, steric, or depletion methods, we will look in detail into the DLVO theory. Key words: charged interfaces, van der Waals interactions, Hamaker coefficient, Derjaguin approximation, Coulomb repulsion, double layer, critical coagulation concentration.

Learning outcomes

By the end of the module, students should be able to:

• KNOWLEDGE: The module will provide students with a solid understanding of several fundamental and contemporary aspects of colloid science focussing on three key learning blocks ( colloid synthesis, colloid motion, colloid stability). Students will develop specialized knowledge in the area of colloid science and integrate this across the wider areas of chemistry, chemical engineering, physics and manufacturing.
• DIVERSE PERSPECTIVES: Through 20 interactive teaching sessions and a group project students will be able to evaluate diverse points of view embedded within varying frameworks which may include, technological/scientific context, societal and environmental impact, temporal and trending contexts.
• COMPETENCY SKILLS: Students will engage in critical inquiry and develop their skill set to process, understand, and communicate/explain and evaluate scientific principles and their impact.
• APPLIED LEARNING: This module has a designed set of exercises associated with each block of learning in which concepts will be applied and integrated in an interactive discussion format.
• COMMUNICATION: Student will be able to communicate effectively in presenting ideas orally, and in the format of an assessed group presentation
• ETHICAL REASONING: Students will be able to reason ethically in evaluating the design and use of colloidal materials in nowadays society and illustrate their learning in the form of a group project/presentation.

Indicative reading list

Reading lists can be found in Talis

Subject specific skills

Understand the underlying mechanistic and physical concepts of polymer colloids from a chemical engineering perspective.
Develop your mathematical modelling skills using Python as a coding tool.

Transferable skills

Presentation delivery