Ultrasmall Particle Sizes of Walnut‐Like Mesoporous Silica Nanospheres with Unique Large Pores and Tunable Acidity for Hydrogenating Reaction

The large particle sizes, inert frameworks, and small pore sizes of mesoporous silica nanoparticles greatly restrict their application in the acidic catalysis. The research reports a simple and versatile approach to synthesize walnut‐like mesoporous silica nanospheres (WMSNs) with large tunable pores and small particle sizes by assembling with Beta seeds. The as‐synthesized Beta‐WMSNs composite materials possess ultrasmall particulate sizes (70 nm), large radial mesopores (≈30 nm), and excellent acidities (221.6 mmol g^?1). Ni₂P active phase is supported on the surface of Beta‐WMSNs composite materials, and it is found that the obtained composite spherical materials can reduce the Ni₂P particle sizes from 8.4 to 4.8 nm with the increasing amount of Beta seeds, which can provide high accessibilities of reactants to the active sites. Furthermore, the unique large pores and ultrasmall particle sizes of Beta‐WMSNs samples facilitate the reduction of the diffusion resistance of reactants due to the short transporting length, thus the corresponding Ni₂P/Beta‐WMSNs composite catalysts show the excellent hydrogenating activity compared to the pure Ni₂P/WMSNs catalyst.     

Organic-templating approach to synthesis of nanoporous silica composite membranes (l): TPA-templating and CO2 separation

Nanoporous silica composite membranes for gas separation have been synthesized by dip-coating the tetrapropylammonium (TPA)-templating silica sols on tubular alumina supports (pore size 2.8–100 nm), followed by eliminating the template via heat-treating at 550–600°C. The NMR spectroscopy of TPABr-silica hybrid composites obtained from the templated silica sols confirmed that TPA molecules (i.e., final pores) were uniformly distributed in the silica matrix. The average pore size and the specific surface area of an unsupported membrane prepared by firing the TPABr (6 wt%)-silica hybrid composite at 600°C were below 18 Å and 830 m²/g, respectively. Any defects such as cracks or pin-holes on the surface of amorphous silica composite membranes were not observed. The CO₂/N₂ separation factor of their composite membranes varied from 3.2 to 10.3 and their gas permeability from 10^–8 to 10^–9 mol/m² · s · Pa depending on the microstructure of aluminar supports.     

Silica‐Templated Synthesis of Ordered Mesoporous Tungsten Carbide/Graphitic Carbon Composites with Nanocrystalline Walls and High Surface Areas via a Temperature‐Programmed Carburization Route

Ordered mesostructured tungsten carbide and graphitic carbon composites (WC/C) with nanocrystalline walls are fabricated for the first time by a temperature‐programmed carburization approach with phosphotungstic acid (PTA) as a precursor and mesoporous silica materials as hard templates. The mesostructure, crystal phase, and amount of deposited graphitic carbon can be conveniently tuned by controlling the silica template (SBA‐15 or KIT‐6), carburizing temperature (700–1000 °C), the PTA‐loading amount, and the carburizing atmosphere (CH₄ or a CH₄/H₂ mixture). A high level of deposited carbon is favorable for connecting and stabilizing the WC nanocrystallites to achieve high mesostructural regularity, as well as promoting the carburization reaction. Meanwhile, large pore sizes and high mesoporosity of the silica templates can promote WC‐phase formation. These novel, ordered, mesoporous WC/C nanocomposites with high surface areas (74–169 m² g^?1), large pore volumes (0.14–0.17 cm³ g^?1), narrow pore‐size distributions (centered at about 3 nm), and very good oxidation resistance (up to 750°C) have potential applications in fuel‐cell catalysts and nanodevices.     

Size‐Dependent Cytotoxicity of Monodisperse Silica Nanoparticles in Human Endothelial Cells

The effect that monodisperse amorphous spherical silica particles of different sizes have on the viability of endothelial cells (EAHY926 cell line) is investigated. The results indicate that exposure to silica nanoparticles causes cytotoxic damage (as indicated by lactate dehydrogenase (LDH) release) and a decrease in cell survival (as determined by the tetrazolium reduction, MTT, assay) in the EAHY926 cell line in a dose‐related manner. Concentrations leading to a 50% reduction in cell viability (TC₅₀) for the smallest particles tested (14‐, 15‐, and 16‐nm diameter) ranging from 33 to 47 µg cm^?2 of cell culture differ significantly from values assessed for the bigger nanoparticles: 89 and 254 µg cm^?2 (diameter of 19 and 60 nm, respectively). Two fine silica particles with diameters of 104 and 335 nm show very low cytotoxic response compared to nanometer‐sized particles with TC₅₀ values of 1095 and 1087 µg cm^?2, respectively. The smaller particles also appear to affect the exposed cells faster with cell death (by necrosis) being observed within just a few hours. The surface area of the tested particles is an important parameter in determining the toxicity of monodisperse amorphous silica nanoparticles.     

Design of Multifunctional Fluorescent Hybrid Materials Based on SiO2 Materials and Core–Shell Fe3O4@SiO2 Nanoparticles for Metal Ion Sensing

Hybrid fluorescent materials constructed from organic chelating fluorescent probes and inorganic solid supports by covalent interactions are a special type of hybrid sensing platform that has gained much interest in the context of metal ion sensing applications owing to their excellent advantages, recyclability, and solubility/dispersibility in particular, as compared with single organic fluorescent molecules. In recent decades, SiO₂ materials and core–shell Fe₃O₄@SiO₂ nanoparticles have become important inorganic solid materials and have been used as inorganic solid supports to hybridize with organic fluorescent receptors, resulting in multifunctional fluorescent hybrid systems for potential applications in sensing and related research fields. Therefore, recent progress in various fluorescent‐group‐functionalized SiO₂ materials is reviewed, with a focus on mesoporous silica nanoparticles and core–shell Fe₃O₄@SiO₂ nanoparticles, as interesting fluorescent organic–inorganic hybrid materials for sensing applications toward essential and toxic metal ions. Selective examples of other types of silica/silicon materials, such as periodic mesoporous organosilicas, solid SiO₂ nanoparticles, fibrous silica spheres, silica nanowires, silica nanotubes, and silica hollow microspheres, are also mentioned. Finally, relevant perspectives of metal‐ion‐sensing‐oriented silica‐fluorescent probe hybrid materials are provided.     

Unique Cobalt Sulfide/Reduced Graphene Oxide Composite as an Anode for Sodium‐Ion Batteries with Superior Rate Capability and Long Cycling Stability

Exploitation of high‐performance anode materials is essential but challenging to the development of sodium‐ion batteries (SIBs). Among all proposed anode materials for SIBs, sulfides have been proved promising candidates due to their unique chemical and physical properties. In this work, a facile solvothermal method to in situ decorate cobalt sulfide (CoS) nanoplates on reduced graphene oxide (rGO) to build CoS@rGO composite is described. When evaluated as anode for SIBs, an impressive high specific capacity (540 mAh g^?1 at 1 A g^?1), excellent rate capability (636 mAh g^?1 at 0.1 A g^?1 and 306 mAh g^?1 at 10 A g^?1), and extraordinarily cycle stability (420 mAh g^?1 at 1 A g^?1 after 1000 cycles) have been demonstrated by CoS@rGO composite for sodium storage. The synergetic effect between the CoS nanoplates and rGO matrix contributes to the enhanced electrochemical performance of the hybrid composite. The results provide a facile approach to fabricate promising anode materials for high‐performance SIBs.     

Hierarchical Composite of Rose‐Like VS2@S/N‐Doped Carbon with Expanded (001) Planes for Superior Li‐Ion Storage

In the present work, a hierarchical composite of rose‐like VS₂@S/N‐doped carbon (VS₂@SNC) with expanded (001) planes is successfully fabricated through a facile synthetic route. Notably, the d‐spacing of (001) planes is expanded to 0.92 nm, which is proved to dramatically reduce the energy barrier for Li⁺ diffusion in the composite of VS₂@SNC by density functional theory calculation. On the other hand, the S/N‐doped carbon in the composite greatly promotes the electrical conductivity and enhances the structural stability. In addition, the hierarchical structure of VS₂@SNC facilitates rapid electrolyte diffusion and increases the contact area between the electrode and electrolyte simultaneously. Benefiting from the merits mentioned above, the VS₂@SNC electrode exhibits excellent electrochemical properties, such as a large reversible capacity of 971.6 mA h g^?1 at 0.2 A g^?1, an extremely high rate capability of 772.1 mA h g^?1 at 10 A g^?1, and a remarkable cycling stability up to 600 cycles at 8 A g^?1 with a capacity of 684.5 mA h g^?1, making it a promising candidate as an anode material for lithium‐ion batteries.     

Hydrophobic properties and color effects of hybrid silica spin-coatings on cellulose matrix

A novel sol–gel derived organic–inorganic hybrid silica sol consisting of organic direct red dye 4BS and inorganic silica (SiO₂) is successfully synthesized by adding coupling agent γ-chloropropyltriethoxysilane (CPTS). Hybrid silica coatings are deposited on cellulose matrix surface via spin-coating approach to introduce effective hydrophobic and color properties. Compared to the dye hybrid silica sol (DHSS), the particle size of CPTS/dye hybrid silica sol (CDHSS) increases from 64.51 to 129.70 nm, while the surface tension reduces from 34.27 × 10⁻³ N m⁻¹ to 31.22 × 10⁻³ N m⁻¹. The hydrostatic pressure of the cellulose matrix coating with CDHSS is 4530.5 Pa, the contact angle is 131.48°, and the wetting time is ~150 min, which attributes to the alkyl chloride aliphatic chain and sharp micro-surface roughness of the hybrid coatings validated directly by AFM and SEM images. The K/S value (5.15) of the cellulose matrix coated with CPTS/dye hybrid silica (CMCCDHS) is 12.44% higher than that of the cellulose matrix coated with dye hybrid silica (CMCDHS), and increased by 30.38% relative to the control coated sample. The maximum absorption wavelengths of the matrixes treated with different processes are the same as the maximum absorption wavelength of the silica sols (510 nm).     

Controllable N‐Doped CuCo2O4@C Film as a Self‐Supported Anode for Ultrastable Sodium‐Ion Batteries

Rational synthesis of flexible electrodes is crucial to rapid growth of functional materials for energy‐storage systems. Herein, a controllable fabrication is reported for the self‐supported structure of CuCo₂O₄ nanodots (≈3 nm) delicately inserted into N‐doped carbon nanofibers (named as 3‐CCO@C); this composite is first used as binder‐free anode for sodium‐ion batteries (SIBs). Benefiting from the synergetic effect of ultrasmall CuCo₂O₄ nanoparticles and a tailored N‐doped carbon matrix, the 3‐CCO@C composite exhibits high cycling stability (capacity of 314 mA h g^?1 at 1000 mA g^?1 after 1000 cycles) and high rate capability (296 mA h g^?1, even at 5000 mA g^?1). Significantly, the Na storage mechanism is systematically explored, demonstrating that the irreversible reaction of CuCo₂O₄, which decomposes to Cu and Co, happens in the first discharge process, and then a reversible reaction between metallic Cu/Co and CuO/Co₃O₄ occurrs during the following cycles. This result is conducive to a mechanistic study of highly promising bimetallic‐oxide anodes for rechargeable SIBs.     

A Vesicle Supra‐Assembly Approach to Synthesize Amine‐Functionalized Hollow Dendritic Mesoporous Silica Nanospheres for Protein Delivery

Intracellular delivery of proteins is a promising strategy of intervention in disease, which relies heavily on the development of efficient delivery platforms due to the cell membrane impermeability of native proteins, particularly for negatively charged large proteins. This work reports a vesicle supra‐assembly approach to synthesize novel amine‐functionalized hollow dendritic mesoporous silica nanospheres (A‐HDMSN). An amine silica source is introduced into a water–oil reaction solution prior to the addition of conventional silica source tetraethylorthosilicate. This strategy favors the formation of composite vesicles as the building blocks which further assemble into the final product. The obtained A‐HDMSN have a cavity core of ≈170 nm, large dendritic mesopores of 20.7 nm in the shell and high pore volume of 2.67 cm³ g^?1. Compared to the calcined counterpart without amine groups (C‐HDMSN), A‐HDMSN possess enhanced loading capacity to large negative proteins (IgG and β‐galactosidase) and improved cellular uptake performance, contributed by the cationic groups. A‐HDMSN enhance the intracellular uptake of β‐galactosidase by up to 5‐fold and 40‐fold compared to C‐HDMSN and free β‐galactosidase, respectively. The active form of β‐galactosidase delivered by A‐HDMSN retains its intracellular catalytic functions.     

Nonlinear optical materials: Synthesis,characterizations, thermal stability and electro-optical properties

Two series of thermal stable polyimides and polyimide/silica hybrid materials have been synthesized. The silica content in the hybrid materials was varied from 0 to 22.5 wt.% and SiO₂ phase was well dispersed in the polymer matrix. The glass transition temperature (T_g) and the decomposition temperature (T_d) were in the range 226–382 °C and 345–499 °C, respectively, for materials. The polymer solutions could be spin coated on the indium–tin–oxide (ITO) glass or other substrates to form optical quality thin films. The electro-optic coefficients (γ₃₃) at the wavelength of 832 nm for polymer thin films poled were in the range of 12–25 pm/V and the values remained well (retained > 85% for more than 100 h). The heat capacities of some materials were in the range of 0.9755–1.1821 J K^− 1 g^− 1 for the temperature 273 and 363 K. No thermal anomaly was found in this temperature range. Most of them showed high thermal stability.     

A Magnetic‐Field Guided Interface Coassembly Approach to Magnetic Mesoporous Silica Nanochains for Osteoclast‐Targeted Inhibition and Heterogeneous Nanocatalysis

1D core–shell magnetic materials with mesopores in shell are highly desired for biocatalysis, magnetic bioseparation, and bioenrichment and biosensing because of their unique microstructure and morphology. In this study, 1D magnetic mesoporous silica nanochains (Fe₃O₄@nSiO₂@mSiO₂ nanochain, Magn‐MSNCs named as FDUcs‐17C) are facilely synthesized via a novel magnetic‐field‐guided interface coassembly approach in two steps. Fe₃O₄ particles are coated with nonporous silica in a magnetic field to form 1D Fe₃O₄@nSiO₂ nanochains. A further interface coassembly of cetyltrimethylammonium bromide and silica source in water/n‐hexane biliquid system leads to 1D Magn‐MSNCs with core–shell–shell structure, uniform diameter (≈310 nm), large and perpendicular mesopores (7.3 nm), high surface area (317 m² g^?1), and high magnetization (34.9 emu g^?1). Under a rotating magnetic field, the nanochains with loaded zoledronate (a medication for treating bone diseases) in the mesopores, show an interesting suppression effect of osteoclasts differentiation, due to their 1D nanostructure that provides a shearing force in dynamic magnetic field to induce sufficient and effective reactions in cells. Moreover, by loading Au nanoparticles in the mesopores, the 1D Fe₃O₄@nSiO₂@mSiO₂‐Au nanochains can service as a catalytically active magnetic nanostirrer for hydrogenation of 4‐nitrophenol with high catalytic performance and good magnetic recyclability.     

Coupling PEDOT on Mesoporous Vanadium Nitride Arrays for Advanced Flexible All‐Solid‐State Supercapacitors

Tailored construction of advanced flexible supercapacitors (SCs) is of great importance to the development of high‐performance wearable modern electronics. Herein, a facile combined wet chemical method to fabricate novel mesoporous vanadium nitride (VN) composite arrays coupled with poly(3,4‐ethylenedioxythiophene) (PEDOT) as flexible electrodes for all‐solid‐state SCs is reported. The mesoporous VN nanosheets arrays prepared by the hydrothermal–nitridation method are composed of cross‐linked nanoparticles of 10–50 nm. To enhance electrochemical stability, the VN is further coupled with electrodeposited PEDOT shell to form high‐quality VN/PEDOT flexible arrays. Benefiting from high intrinsic reactivity and enhanced structural stability, the designed VN/PEDOT flexible arrays exhibit a high specific capacitance of 226.2 F g^?1 at 1 A g^?1 and an excellent cycle stability with 91.5% capacity retention after 5000 cycles at 10 A g^?1. In addition, high energy/power density (48.36 Wh kg^?1 at 2 A g^?1 and 4 kW kg^?1 at 5 A g^?1) and notable cycling life (91.6% retention over 10 000 cycles) are also achieved in the assembled asymmetric flexible supercapacitor cell with commercial nickel–cobalt–aluminum ternary oxides cathode and VN/PEDOT anode. This research opens up a way for construction of advanced hybrid organic–inorganic electrodes for flexible energy storage.     

Robust Tin‐Based Perovskite Solar Cells with Hybrid Organic Cations to Attain Efficiency Approaching 10%

The stability of a tin‐based perovskite solar cell is a major challenge. Here, hybrid tin‐based perovskite solar cells in a new series that incorporate a nonpolar organic cation, guanidinium (GA⁺), in varied proportions into the formamidinium (FA⁺) tin triiodide perovskite (FASnI₃) crystal structure in the presence of 1% ethylenediammonium diiodide (EDAI₂) as an additive, are reported. The device performance is optimized at a precursor ratio (GAI:FAI) of 20:80 to attain a power conversion efficiency (PCE) of 8.5% when prepared freshly; the efficiencies continuously increase to attain a record PCE of 9.6% after storage in a glove‐box environment for 2000 h. The hybrid perovskite works stably under continuous 1 sun illumination for 1 h and storage in air for 6 days without encapsulation. Such a tin‐based perovskite passes all harsh standard tests, and the efficiency of a fresh device, 8.3%, is certified. The great performance and stability of the device reported herein attains a new milestone for lead‐free perovskite solar cells on a path toward commercial development.     

Conformal Coating of Co/N‐Doped Carbon Layers into Mesoporous Silica for Highly Efficient Catalytic Dehydrogenation–Hydrogenation Tandem Reactions

To maximize the utilizing efficiency of cobalt (Co) and optimize its catalytic activity and stability, engineering of size and interfacial chemical properties, as well as controllable support are of ultimate importance. Here, the concept of coating uniform thin Co/N‐doped carbon layers into the mesopore surfaces of mesoporous silica is proposed for heterogeneous aqueous catalysis. To approach the target, a one‐step solvent‐free melting‐assisted coating process, i.e., heating a mixture of a cobalt salt, an amino acid (AA), and a mesoporous silica, is developed for the synthesis of mesoporous composites with thin Co/N‐doped carbon layers uniformly coated within mesoporous silica, high surface areas (250–630 m² g⁻¹), ordered mesopores (7.0–8.4 nm), and high water dispersibility. The strong silica/AA adhesive interactions and AA cohesive interactions direct the uniform coating process. The metal/N coordinating, carbon anchoring, and mesopore confining lead to the formation of tiny Co nanoclusters. The carbon intercalation and N coordination optimize the interfacial properties of Co for catalysis. The optimized catalyst exhibits excellent catalytic performance for tandem hydrogenation of nitrobenzene and dehydrogenation of NaBH₄ with well‐matched reaction kinetics, 100% conversion and selectivity, high turnover frequencies, up to ≈6.06 mol_nitrobenzene mol_Co⁻¹ min⁻¹, the highest over transition‐metal catalysts, and excellent stability and magnetic separability.     

Preparation and luminescence properties of ormosil hybrid materials doped with Tb(Tfacac)3phen complex via a sol–gel process

In this paper, silica-based transparent organic–inorganic hybrid materials were prepared via the sol–gel process. Tetraethoxysilane (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS) were used as the inorganic and organic precursors, respectively. The terbium complex, Tb(Tfacac)₃phen (Tfacac=1,1,1-trifluoroacetylacetone, phen=1, 10-phenanthroline) was successfully doped into organically modified silicate (ormosil) matrix derived from TEOS and GPTMS, and the luminescent properties of the resultant ormosil composite phosphors [ormosil/Tb(Tfacac)₃phen] were investigated compared with those of the Tb(Tfacac)₃phen incorporated into SiO₂ derived from TEOS (labeled as silica/Tb(Tfacac)₃phen). Both kinds of the materials show the characteristic green emission of Tb³⁺ ion. The luminescence behavior of the resultant composite products was dependent on the matrix composition. The optimized lanthanide complex concentration in the ormosil/Tb(Tfacac)₃phen was increased compared with in silica/Tb(Tfacac)₃phen. Furthermore, the lifetime of Tb³⁺ in Tb(Tfacac)₃phen, silica/Tb(Tfacac)₃phen and ormosil/Tb(Tfacac)₃phen follows the sequence: ormosil/Tb(Tfacac)₃phen>silica/Tb(Tfacac)₃phen>pure Tb(Tfacac)₃phen.     

Li+‐Containing,Continuous Silica Nanofibers for High Li+ Conductivity in Composite Polymer Electrolyte

Solid‐state electrolytes have recently attracted significant attention toward safe and high‐energy lithium chemistries. In particular, polyethylene oxide (PEO)‐based composite polymer electrolytes (CPEs) have shown outstanding mechanical flexibility and manufacturing feasibility. However, their limited ionic conductivity, poor electrochemical stability, and insufficient mechanical strength are yet to be addressed. In this work, a novel CPE supported by Li⁺‐containing SiO₂ nanofibers is developed. The nanofibers are obtained via sol–gel electrospinning, during which lithium sulfate is in situ introduced into the nanofibers. The uniform doping of Li₂SO₄ in SiO₂ nanofibers increases the Li⁺ conductivity of SiO₂, generates mesopores on the surface of SiO₂ nanofibers, and improves the wettability between SiO₂ and PEO. As a result, the obtained SiO₂/Li₂SO₄/PEO CPE yields high Li⁺ conductivity (1.3 × 10^?4 S cm^?1 at 60 °C, ≈4.9 times the Li₂SO₄‐free CPE) and electrochemical stability. Furthermore, the all‐solid‐state LiFePO₄‐Li full cell demonstrates stable cycling with high capacities (over 80 mAh g^?1, 50 cycles at C/2 at 60 °C). The Li⁺‐containing mesoporous SiO₂ nanofibers show great potential as the filler for CPEs. Similar methods can be used to incorporate Li salts into other filler materials for CPEs.     

Graphene Caging Silicon Particles for High‐Performance Lithium‐Ion Batteries

Silicon holds great promise as an anode material for lithium‐ion batteries with higher energy density; its implication, however, is limited by rapid capacity fading. A catalytic growth of graphene cages on composite particles of magnesium oxide and silicon, which are made by magnesiothermic reduction reaction of silica particles, is reported herein. Catalyzed by the magnesium oxide, graphene cages can be conformally grown onto the composite particles, leading to the formation of hollow graphene‐encapsulated Si particles. Such materials exhibit excellent lithium storage properties in terms of high specific capacity, remarkable rate capability (890 mAh g^?1 at 5 A g^?1), and good cycling retention over 200 cycles with consistently high coulombic efficiency at a current density of 1 A g^?1. A full battery test using LiCoO₂ as the cathode demonstrates a high energy density of 329 Wh kg^?1.     

New mesoporous silica/carbon composites by in situ transformation of silica template in carbon/silica nanocomposite

Hard template-based fabrication of mesoporous carbon unavoidably goes through the removal process of the template to generate template-free carbon replica, including troublesome disposal of template waste often accompanied by toxic etchant, which not only increases the fabrication cost of materials but also raises serious environmental concerns. As a novel strategy to overcome such problem, a direct in situ synthesis approach using silica waste in carbon/silica nanocomposite as a silica source and cetyltrimethylammonium bromide as a porogen under basic condition is reported in this study for the generation of a new composite composed of mesoporous MCM-41 silica and hollow carbon capsule. The resultant MCM-41/carbon capsule composite offers a 3-D interconnected multimodal pore system, which discloses a wide pore range of ordered uniform mesopores (ca 2.3?nm) resulting from MCM-41 silica and disordered uniform mesopores (ca 3.8?nm) and macropores (ca 300?nm) from hollow mesoporous carbon, respectively. The composite has a high specific surface area (ca 909?m²/g) and large pore volume (ca 0.73?cm³/g). The in situ transformation approach of silica waste into valuable mesoporous silica is considered as a promising scalable route for efficient new multi-functional composites useful for a wide range of applications such as adsorption of volatile organic compounds and radioactive wastes produced in a nuclear facility.     

Piezoelectric properties of collagen-nanocrystalline hydroxyapatite composites

In this paper we did a study of the physicochemical, dielectric and piezoelectric properties of anionic collagen and collagen-hydroxyapatite (HA) composites, considering the development of new biomaterials which have potential applications in support for cellular growth and in systems for bone regeneration. The piezoelectric strain tensor element d ₁₄, the elastic constant s ₅₅, and the dielectric permittivity ₁₁ were measured for the anionic collagen and collagen-HA films. For the collagen-HA composite film (Col-HACOM) the main peaks associated to the crystalline HA is present. For the nanocrystalline composite, nanometric HA powder (103 nm particle size) (HAN), obtained by mechanical milling were used. For the composite film (Col-HAN) the HA and CaH(PO₄)₂H₂O phases were detected. One can see that the HA powder (HAN) present the main peaks associated to crystalline HA. The IR spectroscopy measurements on HA-COM and HAN powders, Col-HACOM and Col-HAN composite films and collagen film (Col) presents the main resonances associated to the modes of (PO₄)^3–, (CO₃)^2–. The IR spectra of Collagen Film (Col) shows the bands associated to amide I (C=O), amide II (N–H) and amide III (C–N) vibrational modes. The scanning electron photomicrography of the Col-HACOM and Col-HAN films, respectively, shows deposits of HA on the surface of collagen. It also shows that HACOM crystals has a dense feature, whereas the HAN crystals has soft porous surface. Energy-dispersive spectroscopy (EDS) analysis showed that the main elements of the hybrid sponge were carbon, oxygen, calcium, and phosphorus. The EDS of HACOM crystal, present in the Col-HACOM composite showed a molar ratio Ca/P = 1.71, whereas the Col-HAN composite the molar ratio of calcium and phosphorus (Ca/P = 2.14) and the amount of carbon were greater. The piezoelectric strain tensor element d ₁₄ obtained for the anionic collagen was around 0.102 pC/N. The collagen composite with nanocrystalline HA crystals (Col-HAN) present a better result (d ₁₄ = 0.040 pC/N) compared to the composite with the commercial ceramic (d ₁₄ = 0.012 pC/N). This is an indication that the nanometric particles of HA present little disturbance on the organization of the collagen fibers in the composite. In this situation the nanometric HA are the best candidates in future applications of these composites.