从生物矿化到碳矿化:仿生材料制备新策略OA

Through billions of years of natural selection,nature has nurtured a wide range of biomaterials with exquisite microstructures,excellent mechanical properties,and unique functional characteristics.Their advantages in resource utilization efficiency and sustainable preparation processes provide important references for the development of artificial materials.However,current biomimetic material research faces a significant contradiction:biomimetic designs pursuing high performance often rely on high-energy consumption preparation processes such as high temperature and high pressure,which achieve performance breakthroughs but contradict sustainable development goals.In contrast,green preparation technologies imitating biomineralization face engineering transformation challenges such as performance,efficiency,and costs,leading to an imbalance of"performance priority"and"process lag"in the field of biomimetic materials.Most existing preparation strategies rely on energy-intensive processes such as high temperature(above 1000℃)sintering or ultrahigh pressure(exceeding 800 MPa)molding,which not only increase production costs(energy consumption accounts for over 60%of total costs for high-temperature ceramics)but also limit the incorporation of thermally sensitive functional components and large-scale industrialization. To address this challenge,extensive studies have been conducted on the regulatory mechanisms of natural biomineralization,revealing five core principles:molecular recognition,confined growth,organic templating,amorphous precursor transformation,and multi-scale synergistic assembly.Nacre,a representative biological mineral,consists of 95%aragonite calcium carbonate and 5%organic matrix,forming a unique"brick-and-mortar"layered structure.Its formation involves the secretion of β-chitin as a porous scaffold by mantle cells,followed by the assembly of silk fibroin and acidic proteins into a gel network,which precisely regulates crystal growth and interlayer spacing.Inspired by these mechanisms,researchers have developed various biomimetic preparation strategies,including freeze casting,layer-by-layer self-assembly,electrophoretic deposition,and 3D printing.For instance,freeze casting has been used to prepare alumina-cyanate composites with a 3D interlocking skeleton,achieving a flexural strength of 300 MPa and a fracture strain of 5%after sintering at 1600℃for 4 h.Room-temperature high-pressure cold sintering technology has enabled the densification of vaterite powder into ceramics with a compressive strength of 280 MPa under 280-800 MPa.Low-temperature low-pressure strategies,such as evaporation-induced self-assembly combined with hot pressing,have produced phosphate-based composites with a flexural strength of 267 MPa,exceeding that of natural nacre(172 MPa).Ambient-temperature and pressure approaches,represented by cement-based biomimetic materials,have utilized ice templating to create porous structures with 200%higher compressive strength than foamed cement,but suffer from low flexural strength(only 5 MPa)and long curing cycles(28 d). A breakthrough strategy based on carbon mineralization has emerged as a promising solution for green biomimetic material preparation.Carbon mineralized materials,also known as Engineered LimeStone(ELS),are novel inorganic non-metallic composites formed by the mineralization reaction between CO2-sequestering cementitious materials(e.g.,steel slag,magnesium slag,or calcium silicates)and gaseous CO2 under ambient conditions,converting CO2 into solid calcium carbonate(CaCO3)as the main matrix.This technology mimics natural biomineralization processes such as shell formation and limestone weathering,achieving permanent CO2 sequestration while producing high-value materials.Three key advantages make ELS ideal for biomimetic systems:mild reaction conditions(ambient temperature and pressure,driven by thermodynamic feasibility and surface-activated CO2 dissolution),highly controllable composition and structure(tunable CaCO3 crystal phases,morphologies,and growth rates via organic modifiers or bacterial treatments),and excellent mechanical properties and durability(compressive strength exceeding 200 MPa after 24 h of curing,superior corrosion resistance). Recent studies have demonstrated the versatility of carbon mineralization-based biomimetic design:1)Inspired by nacre's"brick-and-mortar"structure,ice templating combined with rapid carbon mineralization has produced lightweight high-strength materials with a flexural strength of 45 MPa(8 times higher than cement-hydrogel composites)and a fracture toughness of 2.03 MJ/m3(20 times higher than unmodified ELS).2)Mimicking the"privileged space"in marine biomineralization,sodium alginate hydrogels have been used to create microcompartments for oriented CaCO3 growth,resulting in materials with a compressive strength of 300 MPa and a CO2 sequestration capacity of 200 kg per ton.3)Inspired by natural marble's radiative cooling effect,engineered marble radiative cooling materials(EMM)have been developed via γ-dicalcium silicate(γ-C2S)carbonation,achieving a solar reflectance of over 95%and an atmospheric window emissivity of over 97%,reducing surface temperature by 8.8℃below ambient and sequestering 357.7 kg CO2 per ton. Summary and Prospects Despite significant progress in biomimetic material design,the trade-off between performance and energy consumption remains a major barrier to industrialization.Traditional strategies rely on harsh conditions(high temperature,high pressure)or suffer from insufficient mechanical properties and long curing cycles.ELS address these limitations by integrating mild preparation conditions,rapid curing,high strength-toughness synergy,large-scale scalability,and CO2 sequestration.By combining structural and process bionics,this strategy breaks through traditional performance limits and provides a sustainable solution for biomimetic material commercialization.Future research should focus on optimizing the carbon mineralization reaction efficiency,expanding the range of CO2-sequestering raw materials,and developing multifunctional composites for extreme environments(deep sea,polar regions)and advanced applications(sustainable infrastructure,carbon-neutral buildings,energy-efficient construction).This integration of bionics and green manufacturing not only advances material science but also contributes to global climate goals and the transition to a low-carbon economy.