Pressure-driven fusion of amorphous particles into integrated monoliths

Abstract

Biological organisms can use amorphous precursors to produce inorganic skeletons with continuous structures through complete particle fusion. Synthesizing monoliths is much more difficult because sintering techniques can destroy continuity and limit mechanical strength. We manufactured inorganic monoliths of amorphous calcium carbonate by the fusion of particles while regulating structurally bound water and external pressure. Our monoliths are transparent, owing to their structural continuity, with a mechanical strength approaching that of single-crystal calcite. Dynamic water channels within the amorphous bulk are synergistically controlled by water content and applied pressure and promote mass transportation for particle fusion. Our strategy provides an alternative to traditional sintering methods that should be attractive for constructing monoliths of temperature-sensitive biominerals and biomaterials.

Calcium carbonate: controlled synthesis, surface functionalization, and nanostructured materials

“…78 It is hypothesized that the organic matrix acts either as a substrate for heterogeneous nucleation or as an inhibitor of nucleation or crystal growth via adsorption. 82 Besides the above-mentioned methods, some other synthesis strategies that have varying levels of efficiency, such as the decomposition of Ca(HCO 3 ) 2 , 83 spray drying techniques, 84 electric field-controlled crystallization, 85 ultrasonic irradiation, [86][87][88] inorganic ion polymerization reactions, 89 and the fusion of amorphous precursors under pressure, 90 have also recently been developed.…”

Local Heating Transforms Amorphous Calcium Carbonate to Single Crystals with Defined Morphologies

“…Course control over crystal morphology has also been gained when ACC monoliths with defined water contents were placed under external pressure. [26] As shown to great effect by biology, superior control over crystallization can be achieved by independently controlling both nucleation and growth. This is again easier to accomplish with an ACC precursor than ion-by-ion growth, where ACC can be long-lived when confined in small volumes, [27] giving organisms the opportunity to define when and where nucleation occurs.…”

“…Course control over crystal morphology has also been gained when ACC monoliths with defined water contents were placed under external pressure. [ 26 ]…”

A nanoconcrete welding strategy for constructing high-performance wound dressing

“…However, popular methods of modifying polymers with CaCO 3 nanoparticles still depend on weak interfacial attraction. It is worth noticing that amorphous CaCO 3 exhibits polymer-like flexibility, enabling it to copolymerize with polymers and also to encapsulate micelles, carbon nanodots, gold nanoparticles, macromolecules, small-molecule amino acids and fluoresceins during its crystallization [ [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] ]. Therefore, we here hypothesize that powerfully welding polymer chains within CaCO 3 nanocrystal through siphoning-induced occlusion, hydration-driven crystallization and dehydration-driven compression of amorphous mesoporous CaCO 3 nanoconcretes will possibly more effectively enhance the strength and toughness of the polymer.…”