Nanomaterials in a powdered form are challenging to use in laboratory concrete specimen casting. This is due to the minute-sized particles and the safety considerations. Therefore, there is a need to use nanomaterials in liquid form without altering their properties when used in the casting of concrete specimens.
Colonel Sudhir Mudigere Rangappa
Microemulsions are suitable for your purposes. For example, the creation in laboratory conditions of a microemulsion, an aqueous solution from the EMULSOL XTS concentrate, for the preparation of a lubricant and release fluid for the purpose of separating a concrete product from all types of formwork and molds in the production of concrete structures.
https://www.soltri.ru/microemulsia-hts.html
Colonel Sudhir Mudigere Rangappa
2 quotes from those greater than I:
'I think dry nanotechnology is probably a dead-end' Rudy Rucker Transhumanity Magazine (August 2002)
‘If the particles are agglomerated and sub-micron it may be impossible to adequately disperse the particle… ‘The energy barrier to redispersion is greater if the particles have been dried. Therefore, the primary particles must remain dispersed in water...’ J H Adair, E. Suvaci, J Sindel, “Surface and Colloid Chemistry” Encyclopedia of materials: Science and Technology pp 8996 - 9006 Elsevier Science Ltd. 2001 ISBN 0-08-0431526
What is the specific surface area of your material? If it's not more than 60 m2/cm3 then it can't be considered nano. There will be no free, independent, discrete particles < 100 nm in such a system. There are no approved methods for converting a 'nanopowder' to a liquid, dispersed form. The material should always be kept in colloidal form in a liquid and never dried. Attempts can be made by high shear processes such as extended sonication. Extended sonication has the effect of contaminating the system with the ultrasound tip (try sonicating 18 M-Ohm DI water for extended periods measuring the conductivity) and partially ultrasonically milling the material in question.
The reason is that van der Waals forces combined with solid-solid diffusion render a powder of small primary sized particles to be a mix of sub- and post micron aggregates (tightly bound) and looser agglomerates (which can be dispersed by ultrasound). For further information see these webinars (free registration required):
Dispersion and nanotechnology
https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W190528DispNanoMat
Adhesion and cohesion
https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W180725AdhesionCohesion
See the attached classic picture by Hans Rumpf of gold particles on an anthracene surface where that surface has been distorted and bent upwards toward the gold particles from these attractive forces.
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