HALF DAY SEMINAR

Speaker:  Mr.Pascal Bru, Director International marketing of M/s Formulaction, FRANCE

Date : Nov. 12^th, 2008

14:00-15:30  “Optical  determination of stability of emulsion/suspension”

15:30-15:45 Tea

15:45- 16:45  “ Drying analysis of coatings” 

Abstracts:

Optical  determination of stability of emulsion/suspension (TURBISCAN)

Characterization of colloidal systems and investigation of their stability
is of prime importance for the formulator who wants to optimize the
development of new products. It is of prime importance to detect at an early
stage these phenomena in order to shorten the ageing tests and to improve
the formulations.

We present a technique, based on Multiple Light Scattering (MLS) to measure
and analyze instability phenomena in liquid colloidal dispersions.

It is also a useful technique to characterize the dispersion state of
colloidal samples (for quality control purposes) and the mean diameter of
particles in dispersions (for analytical purposes) The instrument is able to
discriminate concentration and particle or aggregate size variations and to
detect those phenomena much earlier than the operator's naked eye especially
for opaque and concentrated systems.

We then present a few examples of dispersion destabilisation analysis with
the TURBISCAN.


Drying analysis of coatings

The process of coating is used for example in paint deposition on building
wall, metal, plastic, nails, etc ... or ink deposition for printing industry
(ink jet printer, rotative, ...). Paint coating consists in depositing a
thin layer (from few microns to few hundred microns) of a liquid product on
a substrate and having the viscosity of the product increasing by solvent
evaporation, binding effect or chemical reaction. For ink deposition the
product is a pigment suspension or dye solution deposited on paper substrate
or other materials. All these are called DRYING or FILM FORMATION.

We propose here an optical instrument, called HORUS that monitors the drying
process of any product deposited on any substrate. This is based on a new
optical technology, ASII, is presented, for the study of film formation. 

Various film-forming products have been investigated, including water-borne
coatings, on various types of substrates. A wide range of information can be
extracted such as objective drying times (dust-free, dry-hard times, etc) or
mechanism taking place, thereby offering new possibilities to analyse film
formation from complex colloidal systems.