Protective coating of highly porous alginate aerogel particles in a Wurster fluidized bed

• Published in: Powder technology 2022-04, Vol.402, p.117331, Article 117331
• Main Authors: Akgün, Işık Sena, Demir, Enis, Işık, Murat, Ekmekçiyan, Nadin, Şenses, Erkan, Erkey, Can
• Format: Article
• Language: English
• Subjects: Aerogel particle; Alginate; Coating; Polymer; Wurster fluidized bed
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2022.117331

Alginate aerogel particles were successfully coated with a copovidone and hydroxypropyl cellulose based polymer in a Wurster fluidized bed. The results indicate that the pores of aerogels were not damaged during the process. Several sets of experiments were conducted at three different temperatures and atomizing air pressures. Coating time for all the runs ranged from 5 min to 40 min and the coating thickness ranged from 12.4 ± 4.6 μm to 170.6 ± 43.3 μm. Changing bed temperature led to significant changes in coating thickness whereas both bed temperature and atomizing pressure affected coating layer surface morphology. The smoothest coating layer surface and the highest coating efficiency which was 69.2 ± 0.4% were achieved at 50 °C with 1.7 bar atomizing pressure. At this condition, the coating layer thickness increased linearly with coating time. [Display omitted] •Alginate aerogel particles were successfully coated in a Wurster fluidized bed.•The highest coating layer thickness was 170.6 ± 43.3 μm.•Effects of temperature and atomizing pressure on coating thickness were studied.•Coating surface morphology changed with both temperature and atomizing pressure.•Rheology of coating solution governed spreading and adhesion of coating droplets.