Spray Drying Techniques for Nanoparticle Production

Abstract

This report deals with metastability related to nanomaterials, which, in most cases, is driven through their high surface-to-volume ratio into tendencies like aggregation or structural changes when the systems seek to reduce surface energy. Such instability poses a great challenge in preserving nanomaterials, especially in the case of transitioning from synthesis in aqueous or solvent mediums to dry forms that are necessary for practical applications. However, conventional drying methods, such as oven and vacuum drying, may present certain undesirable effects that include material aggregation, re-stacking, and sintering, which could deteriorate the structural integrity and functionality of the nanomaterials. Against this backdrop, spray drying has emerged as a more economical alternative to freeze-drying, which, though effective, is prohibitively expensive for large-scale applications. This paper also presented the general application of the spray drying technique in preserving all kinds of nanomaterials. In particular, pharmaceuticals, nutraceuticals, and fertilizers have been highlighted to take advantage of this technology. Some classifications of utilized materials and their properties are also summarized. Additionally, a few tables containing studies conducted by research groups regarding nanomaterials such as pharmaceuticals, nutraceuticals, nanofertilizers, cosmeceuticals, and other industrial applications. This comparative study shows the economic and functional benefits of spray drying for the preservation of nanomaterials.