Synthesis of High Specific Surface Area Macroporous Pectin Particles by Template-Assisted Spray Drying

Abstract

Many types of porous particles containing inorganic and organic substances, such as carbon, metals, metal oxides, inorganic−organic hybrids, and polymers, have been developed. However, natural polymer-derived particles are relatively rare. To our knowledge, this report describes the first synthetic method for obtaining meso-/macroporous particles made from pectin, which is a natural polymer with a wide range of biological activities suitable for active substance support applications. These porous particles were prepared using a template-assisted spray-drying method, followed by a chemical etching process. An organic template [i.e., poly(methyl methacrylate) (PMMA)] or an inorganic template [i.e., calcium carbonate (CaCO 3 )] was used to evaluate the resulting formation of macroporous structures in the pectin particles. Furthermore, the concentration of the templates in the precursor solution was varied to better understand the mechanism of porous pectin particle formation. The results showed that the final porous particles maintained the characteristic properties of pectin. The differences between the two templates resulted in two distinct types of porous particles that differed in their particle morphologies (i.e., spherical or wrinkled), particle sizes (ranging from 3 to 8 μm), pore sizes (ranging from 80 to 350 nm), and pore volume (ranging from 0.024 to 1.40 cm 3 g −1 ). Especially, the porous pectin particles using the CaCO 3 template have a significantly high specific surface area of 171.2 m 2 g −1 , which is 114 times higher than that of nonporous pectin particles. These data demonstrated the potential for using PMMA and CaCO 3 templates to control and design desired porous materials.

Crystalline Rearranged CD-MOF Particles Obtained via Spray-Drying Synthesis Applied to Inhalable Formulations with High Drug Loading

“…The CD-MOF and LVFX/CD-MOF particles prepared via spray-drying exhibited a dented spherical morphology with diameters of several micrometers and below (Figure a,b). The spherical morphology of spray-dried particles may be attributed to small droplet size . As small droplets have a stable structure, the product particles may have similar shapes to the initial droplet.…”

“…The spherical morphology of spray-dried particles may be attributed to small droplet size. 46 As small droplets have a stable structure, the product particles may have similar shapes to the initial droplet. During the evaporation of solvent inside a droplet, the concentrated solute on the droplet surface forms a solid shell.…”

Recent Advances in the Fabrication and Functionalization of Nanostructured Carbon Spheres for Energy Storage Applications

“…Because of these advantages, such methods are frequently used to produce dry powders in the food, pharmaceutical, and chemical industries. Generally, depending on the operating conditions, solid or hollow spherical particles can be produced in the spray process (Cao et al, 2021b;2021a;Nguyen et al, 2021;. Feng et al prepared pomegranate-like carbon microspheres (PCSs) by fabricating monodisperse, submicron CSs via a scalable template-free spray drying-assisted approach (Feng et al, 2019).…”

Modulating the Pore Architecture of Ice-Templated Dextran Microparticles Using Molecular Weight and Concentration

“…Due to these favorable properties, dextran is also considered in this study. In spray drying, the competition between evaporation and solute diffusion in regulating the onset of precipitation determines the final morphology of the product, which can yield hollow, solid, and crumpled particles. − Although spray drying is conventionally used for preparing fine particles with a porous or amorphous structure due to the ease of controlling the particle size and morphology via the drying rate, , ice represents a more convenient templating agent as it can be readily removed by sublimation, thereby subjecting the excipient to less severe physicochemical stresses compared to dissolution and thermal decomposition utilized in templated spray drying approaches. − The particle size in SFD is largely determined by the droplet size distribution produced by the atomizer as very little evaporation takes place during the SFD process. In this comparatively larger final particle volume, a percolating structure is attained via the process of cryo-concentration, during which ice growth pushes the solution into filamentous and lamellar arrangements as polymers are not typically incorporated into the ice crystal structure and are therefore subject to an increase in concentration in the remaining unfrozen solution (Figure ).…”