Curd fibres

A mixture of soap crystals in a saturated solution in which the soap crystals produce a gel-like consistency. The soap crystals in this case are referred to as curd-fibres . Soap curd is not a mesomorphic (liquid-crystal) phase. 

Curd fibres, soap crystals, which separate out of the solution at high concentration or on addition of much electrolyte. 

Aqueous soap solutions can be obtained in three distinct forms, the sol form containing the ionic micelle, a clear gel, and a white opaque solid the curd. The sol and gel forms of various soaps have been examined by McBain and his co-workers and shown to differ only in elasticity and rigidity, whilst the electrical conductivity, refractive index, concentration of metallic ion and lowering of the vapour pressure are all identical, results to be anticipated on the fibrillar theory. The gel as we have seen is fibrillar in nature and the conversion of a gel into a curd is brought about by the removal of soap fi om solutions in the form of relatively coarse fibres, a process similar to crystallisation. The experiments of Laing and McBain... 

Considerable research was undertaken into methods of improving the quality of the protein curd. Denatured soya bean protein tends to aggregate rather than crystallise so many of the modifications were intended to overcome this adhesive-like behaviour which gave rise to a variety of technical problems. US Patent 2,112,210 describes a process in which the protein was solubilised in sodium hydroxide, treated with carbon disulphide and oxidised with air. It was hoped that this method would result in a fibre with better spinning viscosity, stability and tensile strength. 

---