Events. Structure. Revenue. Portfolio. Capabiliy. Philosophy. Support. Competence. Nanoparticles as UV absorbers. Nano Functional Materials. (NFM) project. יום עיון : יישומי ננו טכנולוגיה בתעשיית הפלסטיקה והגומי . שנקר, בי"ס גבוה להנדסה ועיצוב . ינואר 2007. Support program for:
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Nanoparticles as UV absorbers.
Nano Functional Materials.
יום עיון: יישומי ננו טכנולוגיה בתעשיית הפלסטיקה והגומי .
שנקר, בי"ס גבוה להנדסה ועיצוב.
Researchers from 3 academic institutions.
Three leading projects:
Manufacturing and stabilization of nano particles in liquid phase.
Compounding nano particles into polymers matrix.
De-agglomeration of nano particles.
Positive interaction with polymer to obtain specific advantages. e.g. nanoclays –improves mechanical properties and transparent.Why nanoparticles additives ?
Agglomeration interferes with functional dispersion.
Surface treatments, dispersing agents…
Adjusting process parameters.
Evaluation of the dispersion quality: TEM, SEM and…
Areas of activity:
UV absorbers/blockers: nanosized ZnO, organic UVA nano-particles.
Flame retardants.Kafrit’s activities:
With UV blockingUV absorbed/blocked films for pest control.
Advantages of UV absorbers in Greenhouse Films:
*This is the reason why, in commercial applications, UV blocked AgriFilms is also called “AntiVirus”
Benefits:UV light filtering can prevent undesirable changes of the color, odor, flavor and nutrients.
Effective blocking in thin films – no migration/”blooming”.
Myoglobin (red) Metmayoglobin (brown)
UV absorbers are lost as the results of photodecomposition and migration.
Preliminary particles size 50-60 nm.
In practice: aggregates of 1-2 mm.
Influence of dispersing aid/surfactant type on ZnO dispersion.
By Prof. Y. Cohen (Technion)
ZnO - UV blocking effect maintains for longer period of time compares to the organic UVA.
Org UVA_2Long lasting UV blockage/Pesticides influence.
Faster deterioration of UV blockage in the formulations based on nanosized ZnO compares to the organic UVA as the result of sulfur burning.
There is strong relation between UV blockage deterioration and amount of sulfur applied.
Chemistry: Improved dispersion with the proper surfactant.
High transparency and low light scattering.
Further steps: influence of processing conditions on the nonoparticles dispersion.
Long lasting UV blockage:
Long term effect without agrochemicals.
Further steps: influence of particles surface treatment onagrochemical’s resistance.
Migration control by nanoparticles.Intermediate conclusions.
Average particles size 280 20 nm.
Nano sized SiO2 .
Surface Modified SiO2
Homogeneous dispersion in PO matrix. (adjustment of proper surfactants and drying conditions of synthesis products).
Not sufficient efficiency of UV blockage.
Further steps:improvement UV absorption efficiency by
Reduction of particle size.
Grafting of UVA monomer on nanosized silica.Organic UVA particles/Summary.
Normalized blocking efficiency