Encapsulation of essential oils by means of complex coacervation

  • We have worked a lot with essential oils to encapsulate them thanks to our different technologies, including complex coacervation which enables us to have a completely natural and biodegradable whole.
  • The coacervation process is carried out in a stirred tank, starting with the dispersion of the essential oil to be encapsulated in the water.
  • The droplet size depends on the shear setting obtained by fine-tuning the stirrer speed.
  • We then introduce electrical charges. These charges will help the microcapsules cling to the textile.
  • Acid is then introduced into the dispersion to modify the PH and thereby create a bond between the two polymers and promote polymerization. This results in the deposition of a compound around the essential oil droplets dispersed in the water.
  • Lastly, the chemical bonds will be formed after having stabilised the structure of the polymer containing the essential oil, by adjusting the PH.
  • These microcapsules in gelatine form are transparent and soft. In our laboratories we can produce watertight microcapsules, or microcapsules with controlled release, whose release rate can be adjusted according to our applications.
  • The complex coacervation technique involves two or more types of polymers, whereas the so-called simple method involves only one polymer. It allows a controlled release of the particles under defined humidity, temperature or pressure conditions. These microcapsules have the advantage of being biodegradable and of natural origin.

Our know-how in the incorporation of essential oil for detergents and softeners

  • We also adjust the hydrophilicity and hydrophobicity of these microcapsules to obtain the best possible affinity for the laundry in the washing machine.

Polymer of natural origin

  • The polymers used are of natural origin in order to meet European standards for microcapsule compounds, which must be biodegradable.
  • Note that the dangerousness of the microcapsules is mainly related to the fragrances they contain. It is this part that is very important and therefore needs to be dealt with systematically.
    It is therefore better to replace synthetic fragrances with essential oils while ensuring that of these products are biodegradable.
  • This approach is valid and identical for all ancillary materials and ingredients used, which must be harmless and also biodegradable.
  • Other formulas can be used for the encapsulation of essential oils, such as emulsion or interfacial polymerization, which we also do. But these very effective solutions lack biodegradability and are not of natural origin.
  • The complex coacervation method remains a powerful means of achieving results in terms of microencapsulation of essential oils and their release on the linen. It currently remains the preferred means of obtaining biodegradable microcapsules with sufficient performance for use in detergents or softeners.

The positive aspects of the microencapsulation of essential oils

  • In the case of essential oil encapsulation, it is important to incorporate special fragrances, which must have large molecules so as not to diffuse through the microcapsule wall, and be insoluble in water so as not to interfere with the coacervation.
  • The oil microcapsules contain at least 35% active ingredient to be used optimally, while being protected by the microcapsule wall obtained by complex coacervation.
  • The essential oil will therefore be used as a fragrance to be encapsulated, for use in the detergent area.
  • When necessary, we can reduce the thickness of the walls of the detergent microcapsules, allowing us to obtain porous microcapsules, which will trap the fragrances and ensure that they are released in a suitable time without mechanical breakage.
  • We can control the thickness of the walls and make the release of the fragrance last over time according to what is required.
    The encapsulation of essential oils through our optimised methods plays an essential role in adding fragrance to natural detergents and softeners, allowing better conservation, protection and ease of incorporation of fragrance in natural and biodegradable detergents for washing clothes. This is environmentally friendly.