Bioinspired Organic–Inorganic Hybrid Magnesium Oxychloride Cement via Chitosan and Tartaric Acid

Abstract

The development of magnesium oxychloride cement (MOC) contributes to reducing CO 2 emissions and recycling potash industrial wastes. Unfortunately, MOC is restricted by its water sensitivity, and fabrication of an MOCbased composite with combined water resistance and compressive strength is still challenging. Bioinspired by marine organisms, we herein proposed an organic−inorganic hybrid strategy to enable such a cementitious material. Under a sustainable development concept, we chose biobased chitosan (CS) and tartaric acid (TA) as organic components, which can provide more active sites for Mg 2+ ions in MOC to construct the stable double chelating network, thus promoting the generation of phase 5. The MOC− CS−TA composite realized the combination of a high compressive strength (52.25, 59.01, and 61.52 MPa at various curing ages, respectively) and an enhanced water resistance coefficient (0.88) compared with other MOC-based materials. The improvement can be attributed to the physical filling and protective effects of gel-like phase 5 and chelating products, which is similar to reef-building oysters and slush-buried sea rocks. This work provides a workable guideline for the practical applications of eco-friendly and highperformance building materials.

Recombinant Human Bone Morphogenic Protein-2 Immobilized Fabrication of Magnesium Functionalized Injectable Hydrogels for Controlled-Delivery and Osteogenic Differentiation of Rat Bone Marrow-Derived Mesenchymal Stem Cells in Femoral Head Necrosis Repair

“…The distribution of Mg substitutes was also confirmed by the respective diffraction peaks of the Mg matrix, which can be indexed to Mg (JCPDS No. 35-0821), as shown in Figure 2B ( Han et al, 2020 ). In addition, the chemical composition and states of the prepared injectable hydrogels were confirmed by XPS survey spectra, as shown in Figure 2C .…”

Marine Sponge-Inspired Organic–Inorganic Double-Network Strategy to Produce Magnesium Oxychloride Cement with Integrated Water Resistance and Compressive Strength

“…MOC/ ASep/TA was produced as described in a previous study. 37 MgCl 2 • 6H 2 O was first dissolved in deionized water and stirred for 3 min. Next, TA (0.5, 1, 2, 3, 4, and 5 wt % of the weight of MgO) was dispersed into the MgCl 2 solution and stirred until transparent.…”

“…Tartaric acid (TA) is the primary byproduct of the wine production industry, and its utilization can promote the green and sustainable development of MOC. 36,37 TA is an outstanding candidate for the second organic network to give rise to the chelation reaction between the carboxyl groups (−COOH) and the Mg 2+ ions in MOC, thus enhancing the water resistance. In addition, TA can form an organic network on the surface of ASep through hydrogen bonds, which is analogous to the collagen surface in marine sponge.…”

Dispersion stability of chitosan grafted graphene oxide nanosheets in cementitious environments and their effects on the fluidity of cement mortar nanocomposites

“…In addition, CS is introduced in cementitious composites, as a superplasticizing agent, to reduce the water-to-cement ratio and controlling the cement hydration reaction, which leads to the formation of a more compact structure and more consistent composites 26 with improved mechanical strength. [27][28][29] All these clues motivated us to use CS, as an environmentally friendly material, to prevent GO nanosheets from agglomeration in cementitious media.…”

“…Moreover, metal ions binding capability of CS 23–25 which leads to hindrance of adjacent Ca 2+ to GO sheets and regulation of electrostatic repulsion and steric hindrance among the sheets makes it a good candidate for adsorbing calcium ions in the calcium‐rich cementitious environment. In addition, CS is introduced in cementitious composites, as a superplasticizing agent, to reduce the water‐to‐cement ratio and controlling the cement hydration reaction, which leads to the formation of a more compact structure and more consistent composites 26 with improved mechanical strength 27–29 . All these clues motivated us to use CS, as an environmentally friendly material, to prevent GO nanosheets from agglomeration in cementitious media.…”