Controlled Crystallization of CaCO₃on Hyperbranched Polyglycerol Adsorbed to Self-Assembled Monolayers

Abstract

The formation of biominerals by living organisms is governed by the cooperation of soluble and insoluble macromolecules with peculiar interfacial properties. To date, most of the studies on mineralization processes involve model systems that only account for the existence of one organic matrix and thus disregard the interaction between the soluble and insoluble organic components that is crucial for a better understanding of the processes taking place at the inorganic-organic interface. We have set up a model system composed of a matrix surface, namely, a self-assembled monolayer (SAM), and a soluble component, hyperbranched polyglycerol. The model mineral calcium carbonate displays diverse polymorphism. It could be demonstrated that the phase selection of calcium carbonate is controlled by the cooperative interaction of the SAM and hyperbranched polyglycerol of different molecular weights (M(n) = 500-6000 g/mol) adsorbed to the SAM. Our studies showed that hyperbranched polyglycerol is adsorbed to polar as well as to nonpolar SAMs. This effect can be related to its highly flexible structure and its amphiphilic character. The adsorption of hyperbranched polyglycerol to the SAMs with different surface polarities resulted in the formation of aragonite for alkyl-terminated SAMs and no phase selection for carboxylate-terminated SAMs.

Hyperbranched Polyesters with Carboxylic or Sulfonic Acid Functional Groups for Crystallization Modification of Calcium Carbonate

“…Very recently, hb polyglycerol adsorbed to self-assembled monolayers (SAMs) was employed to control CaCO 3 crystallization by Tremel and co-workers. [33] It was found that the polymorph selection was dependent on the surface polarities of the SAMs, aragonite preferably formed for alkyl-terminated SAMs, while no phase selection was observed for carboxylate-terminated ones. [33] Here we present the synthesis of hb polyesters with carboxylic or sulfonic acid functional groups and the biomimetic mineralization of CaCO 3 under the influence of such functionalized hb polymers.…”

“…[33] It was found that the polymorph selection was dependent on the surface polarities of the SAMs, aragonite preferably formed for alkyl-terminated SAMs, while no phase selection was observed for carboxylate-terminated ones. [33] Here we present the synthesis of hb polyesters with carboxylic or sulfonic acid functional groups and the biomimetic mineralization of CaCO 3 under the influence of such functionalized hb polymers. Preliminary investigations show that both polymorph and morphology can be modified by the carboxylic or sulfonic acid functionalized hb polyesters.…”

The self-assembly of CaCO3 crystals in the presence of protein

“…The additives are mainly macromolecules such as poly(acrylic acid) [27,28], poly(methyl acrylic acid) [29], polyacrylate [30], and so on [31][32][33][34][35]. Proteins, existing in life widely, play an important role in the formation of biominerals in vivo [36][37][38][39][40].…”

Peculiarities of the surface crystallization of sodium chloride on mucin films

“…In order to confine the crystallization space of inorganic salts, diverse systems are applied as sub strates: porous stones [1,2,5]; organic and bioorganic templates, including monolayers and LangmuirBlodgett films [7][8][9]; self organized monolayers [10][11][12]; ultrathin organic films [13]; foams [6] and foam films [14]; interfaces between immiscible liquids [15]; and polymer surfaces [13,[16][17][18].…”