Physico-chemical separation process of nanoparticles and nanostructured materials of cosmetic formulations

Transkript

1 Physico-chemical separation process of nanoparticles and nanostructured materials of cosmetic formulations R. R. Retamal Marín, F. Babick, M. Stintz Research Group Mechanical Process Engineering, TU Dresden Nanosafe, 8 th of November

2 SOP-development for characterisation of NM Wetting/Suspending Dispersion Sampling Separation the NM Measurement/Interpretation Measurements and Characterization of NMs Slide 1 of 14

3 Motivation & objective Synthetic amorphous silica (SAS) = nanostructured material used in a wide range of food and cosmetic emulsions wide range of dispersion energies when preparing or applying such products submicron aggregate and/or nanosized particles behaviour of the nanomaterial (NM) dispersibility in aqueous and lipid phases adsorption at fluid-fluid interfaces or on the surface of large particles Objective separation or extraction of SAS of lipid phases by means of organic solvents Measurements and Characterization of NMs Slide 2 of 14

4 Instruments, materials and preparation Measurements and Characterization of NMs Slide 3 of 14

5 Materials and instruments Materials Nanomaterials (NM) in emulsions-based 10 wt.-% pyrogenic synthetic amorphous silica (SAS) 24 wt.-% lipid phase dispersion media: de-ionised water (18.3 MΩcm), filtered at 0.2 μm lipophilic solvent n-heptane (99%), filtered at 0.1 μm Characterisation techniques laser diffraction (LD) HELOS KR (Sympatec/Germany) dynamic light scattering (DLS) HPPS (Malvern/UK) scanning electron microscopy (SEM) Gemini DSM 980 (Zeiss/Germany) Measurements and Characterization of NMs Slide 4 of 14

6 Preparation Preparation emulsion sample 1.0 g emulsion in 49.5 g water and 49.5 g n-heptane Sampling: after sedimentation after centrifugation (4500 rpm) Dispersion and homogenisation of emulsion sample: magnet stirring (Fa. IKA) Filtration grade syringe filter (PTFE membrane) for different pore size 0,1 µm, 1 µm und 5 µm Measurements and Characterization of NMs Slide 5 of 14

7 Results Measurements and Characterization of NMs Slide 6 of 14

8 Methodological procedure Question: How can SAS in cosmetic emulsion (SAS in oil-wateremulsifying agent) be characterised and separated better? Procedure of solution: Interaction of physico-chemical separation process Extraction Oil with organic lipophilic solvent (Hansen,2007) Separation of SAS-particles (sedimentation/centrifugation) Mass balance (preparation of emulsion) Filtration (PTFE membrane) Measurements and Characterization of NMs Slide 7 of 14

9 Evolution of extraction process after 20 h after 1 h centr. n-heptane/ lipid phase SAS-PSD? SAS-PSD?? emulsifying agent, foam? aqueous phase Hydrophobic fumed SiO 2 in water and n-heptane (mix ratio 1:1) Measurements and Characterization of NMs Slide 8 of 14

10 transf. distribution density q3* Fakultät Maschinenwesen Institut für Verfahrenstechnik und Umwelttechnik, AG Mechanische Verfahrenstechnik LD - Evolution of extraction process after 20 h after 1 h centr. 0,8 0,7 0,6 20h MR 1h Zen n-heptane/ lipid phase 0,5 0,4 SAS-PSD? 0,3 0,2 0, Particle size x, µm SAS-PSD?? aqueous phase emulsifying agent, foam? Hydrophobic fumed SiO 2 in water and n-heptane (mix ratio 1:1) Change of size distribution (determined with LD) of a SAS cosmetic emulsion within water phase, realised by magnetic stirrer (MR) and centrifugation (Zen) Measurements and Characterization of NMs Slide 9 of 14

11 Derived count rate, kcps Amplitude Derived count rate, kcps Amplitude Fakultät Maschinenwesen Institut für Verfahrenstechnik und Umwelttechnik, AG Mechanische Verfahrenstechnik DLS - Effectivity of separation der.cr ACF0 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0, der.cr ACF0 1,2 1,0 0,8 0,6 0,4 0,2 0,0 Separation = filtration with membrane DLS-result for the detection of SiO 2 nanoparticles in cosmetic formulation; water phase left: with, right: without SiO 2 Clear trend: count rate with cut size of separation degree of derived count rate (der.cr) for filtration grade (syringe filter; PTFE membrane) Measurements and Characterization of NMs Slide 10 of 14

12 Distribution function QInt transf. distribution density q* Fakultät Maschinenwesen Institut für Verfahrenstechnik und Umwelttechnik, AG Mechanische Verfahrenstechnik SEM analysis 1 1 0,8 0,6 0,4 0,2 QInt q*int 0, effective hydrodynamic diameter, nm Existence of SAS-particles in n-heptane phase? Left: weighted intensity distribution for SiO 2 in n-heptane phase; right: SEM image with high magnification ( finest particles found ); sample carrier: track-etch-membrane with 50 nm pore Measurements and Characterization of NMs Slide 11 of 14

13 Conclusion This investigation verified an alternative procedure to separate particles with regard to the polarity of solvent and solute in such complex media such as cosmetic emulsions This procedure is applicable to O/W and W/O emulsions and it can be employed for hydrophilic as well as hydrophobic SAS Interaction of physico-chemical separation process no presence of sediment after centrifugation stable phases (aqueous phase and lipophilic solvent) presence of a liquid foam (oil-water-emulsifying agent) at the interface between water and heptane discrepancy of density and polarity of solvent play an important role of separation and homogenisation Measurements and Characterization of NMs Slide 12 of 14

14 Thank you for your attention! Measurements and Characterization of NMs Slide 13 of 14

15 References Retamal Marín, R.R.; Babick, F.; Stintz, M.: Characterisation of nanoparticles and nanostructured materials in cosmetic formulations and food products. In: Partec International Congress on Particle Technology, Nuremberg, R.R. Retamal Marín, F. Babick, M. Stintz: Non-normalised size distributions for the interpretation and characterisation of polydisperse suspension and emulsion. PARTEC 2016 Nürnberg, April 2016 R. R. Retamal Marín, F. Babick, M. Stintz: Berücksichtigung der absoluten Signalstärke bei der Charakterisierung von Suspensionen und Emulsionen. ProcessNet Clausthal-Zellerfeld, R. R. Retamal Marín, A. Nogowski, F. Babick: Ultraschalldispergierung von nanopartikulären Systemen. ProcessNet-FG PMT Würzburg, 02. April 2014 F. Babick, et al. Characterization of Pyrogenic Powders with Conventional Particle Sizing Technique: I. Prediction of Measured Size Distributions, Part. Part. Syst. Charact. 29, pp , 2012 Hansen, Charles M. Solubility Parameters - An Introduction. Hansen Solubility Parameters, A User's Handbook, Second Edition, pp CRC Press, 2007 Measurements and Characterization of NMs Slide 14 of 14

16 x Cum, nm x Cum, nm Fakultät Maschinenwesen Institut für Verfahrenstechnik und Umwelttechnik, AG Mechanische Verfahrenstechnik Effectivity of separation - DLS Excel DTS Excel DTS Separation = filtration with membrane DLS-result for the detection of SiO 2 nanoparticles in cosmetic formulation; water phase left: with, right: without SiO 2 Clear trend: count rate with cut size of separation degree of derived count rate (der.cr) for filtration grade (syringe filter; PTFE membrane) Measurements and Characterization of NMs Slide 15 of 14