Spherical and Porous Particles of Calcium Carbonate Synthesized with Food Friendly Polymer Additives

Abstract

Porous calcium carbonate particles were synthesized by adding solutions of Ca 2+ to solutions of CO 3 2− containing polymeric additives. Under optimized conditions welldefined aggregates of the anhydrous polymorph vaterite formed. A typical sample of these micrometer-sized aggregates had a pore volume of 0.1 cm 3 /g, a pore width of ∼10 nm, and a specific surface area of ∼25−30 m 2 / g. Only one mixing order (calcium to carbonate) allowed the formation of vaterite, which was ascribed to the buffering capacity and relatively high pH of the CO 3 2− solution. Rapid addition of the calcium chloride solution and rapid stirring promoted the formation of vaterite, due to the high supersaturation levels achieved. With xanthan gum, porous and micrometer-sized vaterite aggregates could be synthesized over a wide range of synthetic conditions. For the other food grade polymers, hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), and sodium carboxyl methylcellulose, several intensive and extensive synthetic parameters had to be optimized to obtain pure vaterite and porous aggregates. HPMC and MC allowed well-defined spherical micrometer-sized particles to form. We expect that these spherical and porous particles of vaterite could be relevant to model studies as well as a controlled delivery of particularly large molecules.

High-efficiency freezing-induced loading of inorganic nanoparticles and proteins into micron- and submicron-sized porous particles

“…They are administered by various routes, including transdermal 19,22 , inhalation 20 , intertumoral 21 , and peroral 23 . Vaterite particles are also used in the preparation of food-friendly polymer additives 24 and in water purification 25 . However, their transfer from R&D to industrial application has been made difficult by the lack of an efficient loading approach.…”

The mechanism of catalase loading into porous vaterite CaCO3 crystals by co-synthesis

“…Control over the crystal growth provides one with a simple way to adjust the crystal porosity even without any additives. 25,26 The surface of the nanocrystallites can be coated with different materials, for example, lipids, for protection. 27 Some recent efforts have been made in the size reduction of calcium carbonate crystals that open new perspectives to employ the crystals for a wide range of administration routes in modern drug delivery.…”

A biomimetic hybrid material consisting of CaCO3 mesoporous microspheres and an alternating copolymer for reversed-phase HPLC

“…In order to control the morphology of CaCO 3 , crystallization methods involving anionic small molecules 8,9 or anionic polymers [10][11][12] were studied by mimicking the formation process of biominerals. We have also reported that monodispersed mesoporous CaCO 3 microspheres with 20 nm mesopores and controllable particle size can be obtained by a biomimetic process.…”