17 Aug APonics
Chemists at the Radboud University of Nijmegen, the Netherlands, have discovered a polymer gel which has the property of being liquid at low temperature and solid at high temperature. The product name of this material is APonics™. This is unique as the temperature sensitivity of APonics™ is exactly opposite to the how generally hydrogels gelate. The transition from liquid to a gel takes place between 14 and 40 °C (the gel can be adjusted to the desired transition temperature within this range). APonics™ polymer consists of a polyisocyanopeptide having a helical structure which dissolves in water. A detailed description of the polymer synthesis and properties was published in Nature on 24 January 2013 (Responsive biomimetic networks from polyisicyanopeptide hydrogels, 2013;K ouwer, P.H.J. et al.; A.E.Nature, 493, 651 – 655. ISSN 0028-0836).
Another special feature is that only a small amount of the polymer is required to show this property, namely 0.1-0.3% (compared to 1-10% for alternative products). In 2011, a patent application has been submitted to the method of making this compound.
The temperature sensitivity and low polymer content make APonics™ very suitable as additive for biocide applications in greenhouses or arable land during the summer or in hot climates.
The idea to mix the polymer into the biocide solution, which is mainly water with a temperature below 14 °C, and to spray the biocide over the relatively warm plant leaves. Spraying the substance instantly results in droplets that become a gel on top of the leave surface which so that the biocide does not runoff anymore, while the biocide is still in an almost 100 % water solution. The low runoff results in more efficient usage of biocides and there is no effect from the gel (the polymer) on the growth (stomata breathing and photosynthesis) of the plants.
As a result water consumption can be reduced substantially. In many regions in the world water is scarce so that the APonics™ base gel creates another advantage.
The picture below shows the effect of the gel forming a thin film over the leave where the water alone results in the forming of droplets which runoff from the leaves.
The advantages of the APonics™ based additive are:
– more efficient use of biocides (reduction of more than 50%)
– less consumption of water (less than 50%)
– less environmental damage
– the gel alone kills small insects such as spider mites and thrips as they are trapped in the nanosize polymer network and cannot feed and reproduce