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Department of Chemical Engineering

Prof Walter Focke


Position Director, Institute of Applied Materials
Professor, Department of Chemical Engineering 
Telephone +27 12 420 3728
Room 1-45, Chemistry Building, Main Campus

Teaching duties


Thermodynamics CTD 311


Polymer Processing CPP 720
Additive Technology CYM732
Chemical Engineering CIR707

Short courses

Surfactant Technology

Polymer Additives

Download postgraduate brochure on Polymers and Chemical Product Design here

Hobby research topic

Mixture models for correlating the physical properties of mixtures

Publications in peer-reviewed journals

1.        Focke, WW. On the Mechanism of Transfer Enchancement by Eddy Promoters. Electochimica Acta, 28 (1983) 1137.

2.        Focke, WW. Turbulent Convective Transfer in Plate Heat Exchangers. Int. Comm. Heat Mass Transfer 10 (1983) 201.

3.        Focke, WW and Nuijens, PGJM. Velocity Profile Caused by a High Porosity spacer between Parallel Plates (Membranes). Desalination 49  (1984) 243-253.

4.        Focke, WW, J Zachariades and I Oliver, The Effect of the Corrugation Inclination Angle on the Thermohydraulic Performance of Plate Heat Exchanges, Int. J. Heat Mass Transfer 28 (1985) 1469.

5.        Focke, WW, Asymmetrically Corrugated Plate Heat Exchanger Plates.  Int. Comm. Heat Mass Transfer 12 (1985) 67.

6.        Focke, WW and P G Knibbe, Flow Visualization in parallel plate ducts with Corrugated Walls. J Fluid Mech. 165 (1986) 73.

7.        Focke, WW, Selecting Optimum Plate Heat Exchanger Surface Patterns. J. Heat Transfer 108 (1986) 153.

8.        Focke, WW and GE Wnek, Electrochemistry of Polyaniline: Consideration of a Dimer Model, in P N Prasad and D R Ulrich (Eds.) Nonlinear Optical and Electroactive Polymers, Plenum Press, New York, 1987, pp. 315 - 324.

9.        Focke, WW, GE Wnek and Y Wei, Influence of Oxidation State, pH and Counterion on the Conductivity of Polyaniline, J. Phys. Chem. 91 (1987) 5813.

10.     Shah, RK and Focke, WW, Plate Heat Exchangers and Their Design Theory, in R K Shah, E C Subbarao and R A Mashelkar (Eds.), Heat Transfer Equipment Design, Hemisphere Publishing, New York, New York, (1988).

11.     Focke, WW and G E Wnek, Conduction Mechanisms in Polyaniline (Emeraldine Salt), J. Electroanal Chem. 256 (1988) 343.

12.     Ray, A, AG MacDiarmid, J-C Chiang, Y Wei, WW Focke, GE Wnek, and Arthur J. Epstein, Electrochemistry of Ring-Substituted Polyanilines: Effect of Substituents on Electronic Properties, Mol. Cryst. Liq. Cryst., Vol. 3, pp. 245-246, 1988.

13.     Wei, Y, X Tang, Y Sun, and WW. Focke, A Study of the Mechanism of Aniline Polymerization, J. Polym. Sci., Part A, Polym. Chem., Vol. 27, pp. 2385-2396, 1989.

14.     Wei, Y, WW Focke, G E Wnek, A Ray and AG MacDiarmid. Synthesis and Electrochemistry of Alkyl-ring Substituted Polyanilines, J. Phys. Chem. 93 (1989) 495-499.

15.     Focke, WW, Approximate Design Equations for the Membrane Separation of a Two-component Mixture in a Single-Stage Process, S.A.J. Chem. Eng. 2 (1990) 1-14.

16.     Nicolaides, C P, J H Opperman, M S Scurrell and Focke, WW, Metathesis of Fatty Esters Derived from South African Sunflower Oil,  JAOCS 67 (1990) 362.

17.     Nuijens, PGJM, WW Focke and I Olivier, Flow Distribution in Multi-compartment Equipment with Linear Supply and Discharge Manifolds, SA. J. Chem. Eng. 3 (2) (1991) 26-50.

18.     Focke, WW, MS Smit, AT Tolmay, LS van der Walt and WL van Wyk. Differential Scanning Calorimetry Analysis of Thermoset Cure Kinetics:  Phenolic Resole Resin,  Pol. Eng. Sci. 31  (1991) 1665.

19.     Focke, WW and GS van Eeden, Prediction of Cure Time for a Rubber Cement Used for Conveyor Belt Splicing. J. Appl. Pol. Sci. 42 (1991) 591.

20.     Tolmay, AT and WW Focke. Microwave Asssited Curing of Phenolic Resole, SA J Chem. Eng. 3 (1) (1991) 1.

21.     Focke, WW. Heat Transfer Analogies for Plate Heat Exchangers,  SA. J. Chem, Eng. 7 (1) (1995) 1-15.

22.     Focke, WW. The Opacity of Plastic Films: An Empirical Correlation, SA J Chem. Eng. 8 (1996) 1-7.

23.     Focke, WW, CA Strydom and N Bartie. Thermal Analysis of Commercial Inorganic Flame Retardants, SA J Chem. Eng. 9 (2) (1997) 41-51.

24.     W J De Wet and Focke, WW. Improved Sulphuric Acid Sulphation of Refractory Zirconia by Addition of Sodium Sulphate, SA J Chem. Eng. 11 (2) (1999) 29-37.

25.     FJW Labuschagne, WW Focke and CA Strydom. Strong base catalysed intumescent flame retardants, J. Mat. Sci. Let. 19 (2000) 617.

26.     Focke, WW, A New Three-parameter Activity Coefficient Correlation for Modelling Liquid Phase Behaviour. Part 1: Theory, SA J Chem. Eng. 12 (1) (2000) 35-46.

27.     Labuschagné, FJWJ, WW Focke and CA Strydom. Metal Catalyzed Intumescent Flame Retardant Systems, PMSE  220 (2000) 2.

28.     Focke, WW. Local Composition Structured Fluid Model for the Excess Gibbs Energy of Liquid Mixtures, Ind. Eng. Chem. Res. 40 (2001) 2971-2981.

29.     Kruger, A, WW Focke, Z Kwela and R Fowles. Effect of Ionic Impurities on the Crystallization of Gypsum in Wet-Process Phosphoric Acid. Ind. Eng. Chem. Res. 40 (2001) 1364-1369.

30.     Focke, WW. A New Three-parameter Activity Coefficient Correlation for Modelling Liquid Phase Behaviour. Part 2: Application to binary Vapour-Liquid Equilibrium at low Pressures, SA J Chem. Eng. 13 (1) (2001) 1-16. (

31.     Bisschoff, K and WW Focke. Oxygenated Hydrocarbon Compounds as Flame Retardants for Polyester Fabric, in GL Nelson and CA Wilkie (Eds.), Fire and Polymers: Materials and Solutions for Hazard Prevention, ACS Symp. Ser. No. 297, Oxford University Press, Oxford, 2001, pp 240-250.

32.     Eyenga, II,  WW Focke, L.C. Prinsloo and A.T. Tolmay. Photodegradation: A Solution for the Shopping Bag Visual Pollution Problem? S. A. Journal of Science, 97 (2001) 359-362.

33.     Germishuizen, WA, WW Focke and A.T. Visser, A Laboratory Study of Soil Stabilisation with an Urea-Formaldehyde Resin, Journal of the South African Institution of Civil Engineers 44 (2002) 9-12.

34.     Kruger, A, WW Focke, Z Kwela and R Fowles,  Effect of Ferrous and Ferric Iron Impurities on the Crystallization of Gypsum and Sludge formation in Wet-Process Phosphoric Acid, Chemical Engineering Communications 189 (2002) 684 – 694.

35.     Focke, WW, A Manhique and R Carter. Lattice Model for Estimating the Opacity of White Coatings, J. Am. Ceram. Soc. 85 [5] 1139-44 (2002).

36.     Govender, M, WW Focke, A.T. Tolmay and D. Graefe. Evaluation of commercial plastics purging compounds on a laboratory film blower. SA J Chem. Eng. 14 (1) (2002) 16-27.

37.     Vuorinen, E, WW Focke, A. Gandini, S. W-F and  M. Govender. Sythesis of adhesive polyethylene polymers using free radical grafting in a compounding extruder. SA J Chem. Eng. 14 (2) (2002) 1-5.

38.     Labuschagné, FJWJ, and WW. Focke, Metal Catalysed Intumescence: Characterisation of the Thermal Decomposition of Calcium Gluconate Monohydrate, J. Mat. Sci. 38 (6) (2003) 1249-1254.

39.     Arao Manhique, Zola Kwela and WW. Focke, The De Wet Process for the Beneficiation of Zircon: Optimization of the Alkali Fusion Step, Ind. Eng. Chem. Res. 42 (2003) 777-783.

40.     Verbeek, CJR and WW Focke, Modelling the Young’s modulus of platelet reinforced thermoplastic sheet composites, Composites: Part A 33 (2003) 1697 – 1704.

41.     Labuschagné, FJWJ,  SMC. Verryn and WW Focke, X-ray Powder Diffraction Data for Ammonium d-Gluconate, C6H11O-7NH4+, Powder Diffr., 18(2), (2003) 162-164.

42.     Karakatsanis, E, WW Focke and Gabriel Summers Low Molecular Mass Poly(styrene-co-acrylic acid) Amphiphilic Block Copolymers: Synthesis and Characterization, Macromol. Symp. 193 (2003) 187-193.

43.     WW Focke, A revised equation for estimating the vapour pressure of low-volatility substances from isothermal thermogravimetric data, J. Therm. Anal. Cal. 74 (2003) 1107-1118.

44.     Pieterse, N and WW Focke, Diffusion controlled evaporation through a stagnant gas: Estimating low vapour pressures from thermogravimetric data, Thermochimica Acta., 406, 1-2 (2003) 191-198.

45.     Moolman, F.S., Rolfes, H., Van der Merwe, S.W. and Focke, WW  (2004). Optimization of perfluorocarbon emulsion properties for enhancing mass transfer in a bio-artificial liver support system.  Biochem. Eng. J.19(3): 237-250.

46.     Germishuizen, WA, WW Focke and A.T. Visser, A Laboratory Optimisation of a urea-formaldehyde Soil Stabiliser, SA J Chem. Eng. 15 (1) (2003) 1-16.

47.     Isabel M.M. Ricco, Corrie Conradie and WW. Focke, Alternative Oxidants for Silicon Fuel in Time Delay Detonators, Combustion Science and Technology, 176 (9), 1565-1575.

48.     Focke, WW (2004). Excess Gibbs Energy of Binary Liquid Mixtures and the Wong-Sandler Postulates, AIChE J. 50 (12) 3284-3289.

49.     Focke, WW and B. Du Plessis. Correlating Multicomponent Mixture Properties with Homogeneous Rational Functions. Industrial and Engineering Chemistry Research. 43(26) (2004) 8369-8377.

50.     Vuorinen, E, E Kálmán and WW Focke. Introduction to vapour phase corrosion inhibitors in metal packaging. Surface Engineering, 20 (4) (2004)  281-284.

51.     Focke WW; Neural network averaging. Neural Computation 18 (2005) 1-9.

52.     Karakatsanis E, Focke WW, Summers G; Surfactant-assisted micro-mixing of melamine and wax particles, Journal of Applied Polymer Science, 99(5) (2006) 2554-2557

53.     Focke, WW and Grobler, M. Low-pressure vapor-liquid data reduction using only equilibrium composition data. J. Chem. Eng. Japan, 39 (2) (2006) 114-120

54.     Sita C, Burns M, Focke WW. Tensile properties of Thermoplastic Starch-PVB blends, J. Appl. Polym. Sci., 101 (3) (2006) 1751-1755.

55.     Landman EP, Focke WW; Stearate intercalated layered double hydroxides: effect on the physical properties of dextrin-alginate films. Journal of Materials Science, 41 (8) (2006) 2271 – 2279.

56.     Niel Pieterse, Walter W. Focke, Eino Vuorinen and Ilona Rácz (2006). “Estimating the Vapour Pressures of Volatile Corrosion Inhibitors from Isothermal Thermogravimetric Data”. Corrosion Science, 48 (8) 1986-1995.

57.     Landman, EP and Focke, WW. Poly(vinyl sulfonate) intercalation into stearate intercalated layered double hydroxides. SAJS Vol. 102 (11/12) (2007) 581-584.

58.     Carl Sandrock, Walter W. Focke and Schalk Kok. Weighted-power-mean mixture model: Empirical mixing laws for liquid viscosity. Ind. Eng. Chem. Res. 46 (2007) 4660-4666.

59.     Focke, WW; Mixture model for correlating excess enthalpy data, J. Chem. Eng. Jpn., 40 (2007) 295-303.

60.     Suven Pecku, Thilo L. van der Merwe, Heidi Rolfes, Walter W. Focke, Starch as antiblocking agent in breathable polyurethane membranes, Journal of Vinyl and Additive Technology13 (4) (2007) 215-220.

61.     Lonji Kalombo, Olinto Del Fabbro, Corrie Conradie and WW Focke. Sb6O13 and Bi2O3 as oxidants for Si in pyrotechnic time delay compositions. Accepted by Propellants, Explosives, Pyrotechnics.

62.     Nontete Nhlapo, Thatho Motumi, Edith Landman, Sanine MC Verryn and Walter W Focke. Hydrotalcite: surfactant-assisted fatty acid intercalation of layered double hydroxides. Journal of Materials Science, Available online.


1.              W W Focke and C Hechter,“Self vulcanizing rubber” SA Pat. 90/5403 (1990)

2.              W W Focke, “Purging” SA Pat. 90/7073 (1990)

3.              W W Focke and C Hechter,“Polymeric curing reaction” SA Pat. 90/7309 (1990)

4.              W W Focke, P Truter, and MP Whelan, “Hydrolysis of polester resins” SA Pat. 91/6746 (1991)

5.              W W Focke, P Truter, “Beauty slices” SA Pat. 90/7073 (1992)

6.              J Bisschoff and W W Focke, “Oxygenated Hydrocarbons as flame retardants for polyester fabric”, SA Pat 2000/2104 (Granted 30 April 2000).

7.              W W Focke, “Flame Retardant Synergist with Carboxylic acids”, SA Pat 2000/2513   (Granted: 22 May 2000).

8.              W W Focke, “Flame Retardant Synergist with silicate minerals”, SA Pat 2000/2234 (Granted: 8 May 2000).

9.              WW Focke, “Volatile Corrosion Inhibitor”, SA Pat 99/7313.

10.           E. Vuorinen and W.W. Focke, S A Patent (No. 2001/8992) assigned to CSIR entitled: "Coating Material”.

11.           F.J.W.J. Labuschagné, Walter W. Focke and Jan Cornelius Mentz, SA Patent (No. 2002/4876) assigned to University of Pretoria entitled: “Intumescent Flame Retardants”, 2002.

12.           HA de Bruyn and WW Focke, Binder composition and method for treating particulate material, SA Pat 2001/9930 assigned to the University of Pretoria and PCT WO 03/060038.

13.           IM Ricco, SO Sefanyetso and WW Focke, An alternative oxidant for a delay composition, SA Patent 2003/7155 assigned to the University of Pretoria.

14.           L Kalombo, O De Fabro, WW Focke and C Conradie. Alternative oxidant fo a delay composition.  PCT /IB2005/0523 filed 13 July 2005.

15.           E Landman and WW Focke. Fatty acid intercalated layered double hydroxides ZA 2005/02785

16.           Shay, E, Focke, WW Focke and Walbrugh, L. ZA 2005-05664 Pharmaceutical Composition Three provisional South African patents concerning solid pesticide dosage forms filed by Bayer:

                2004/7206 Pharmaceutical Composition (Polymer)
                2004/7207 Pharmaceutical Composition (Eutectic)
                2004/7208 Pharmaceutical Composition (Gel)