Porous Micro Research Articles

Highly Porous Particles of Cellulose Derivatives for Advanced Applications.

A chemical modification of cellulose diacetate by phthalate and nitrate was performed to increase solubility in organic solvents and change the electrical properties. The role of substituents on the conductivity, permittivity, and polarizability of cellulose films is revealed. It has been shown that highly porous micro particles can be obtained from cellulose derivatives by a simple and technological freeze-drying method. The resulting micro sized aerogels have a predominantly spherical morphology and amorphous structure. Suspensions of porous particles of nitro- and phthalylated cellulose derivatives in silicone oil have an increased dielectric permittivity compared to cellulose diacetate particles. Produced particles are novel promising material with tunable electrical properties for advanced applications in composites, including for electrorheological fluids.

A novel nanoparticles spilled-over In2O3 microcubes-enabled sustainable chemiresistor for environmental carbon dioxide monitoring

Achieving sustainable future energy goals includes enhancing renewable energy production, optimizing daily energy consumption using feedback loops and minimizing/monitoring contributions to atmospheric carbon dioxide (CO2). Developing economic next-generation CO2 sensors enables local monitoring of industrial CO2 emissions, aiding energy management and climate monitoring. This study elucidates the efficacy of CO2 chemiresistor based on indium oxide (In2O3) micro cubes with spilled-over nanoparticles. The investigation primarily focuses on fabricating and optimising In2O3-based CO2 chemiresistors utilizing a hydrothermal technique, creating porous micro cubes essential for enhanced CO2 monitoring. As revealed by various characterization techniques, the minimum crystallite size was found to be 24.92 nm with optimum porosity and a high surface-to-volume ratio comprising spilled-over nanoparticle morphology. The fabricated chemiresistor demonstrated excellent CO2 sensing efficacy with a maximum response of around 4.1% at room temperature with selectivity, repeatability, and reversible sensing behavior. The sensing mechanism has been revealed, which is supported by theoretical density functional theory evaluations. Notably, the sensing results reveal the capability of In2O3-based sensors to detect CO2 at low concentrations as low as ⩽10 ppm, which enables the chemiresistor for practical implementation in diverse sectors to achieve sustainability.

Design of Collagen and Gelatin-based Electrospun Fibers for Biomedical Purposes: An Overview.

Collagen and gelatin are essential natural biopolymers commonly utilized in biomaterials and tissue engineering because of their excellent physicochemical and biocompatibility properties. They can be used either in combination with other biomacromolecules or particles or even exclusively for the enhancement of bone regeneration or for the development of biomimetic scaffolds. Collagen or gelatin derivatives can be transformed into nanofibrous materials with porous micro- or nanostructures and superior mechanical properties and biocompatibility using electrospinning technology. Specific attention was recently paid to electrospun mats of such biopolymers, due to their high ratio of surface area to volume, as well as their biocompatibility, biodegradability, and low immunogenicity. The fiber mats with submicro- and nanometer scale can replicate the extracellular matrix structure of human tissues and organs, making them highly suitable for use in tissue engineering due to their exceptional bioaffinity. The drawbacks may include rapid degradation and complete dissolution in aqueous media. The use of gelatin/collagen electrospun nanofibers in this form is thus greatly restricted for biomedicine. Therefore, the cross-linking of these fibers is necessary for controlling their aqueous solubility. This led to enhanced biological characteristics of the fibers, rendering them excellent options for various biomedical uses. The objective of this review is to highlight the key research related to the electrospinning of collagen and gelatin, as well as their applications in the biomedical field. The review features a detailed examination of the electrospinning fiber mats, showcasing their varying structures and performances resulting from diverse solvents, electrospinning processes, and cross-linking methods. Judiciously selected examples from literature will be presented to demonstrate major advantages of such biofibers. The current developments and difficulties in this area of research are also being addressed.

Entropy and Non-Fourier Flux on Hydro-magnetic Flow Among Nonlinearly Radiated Porous Micro Walls Filled with Blood-Based Different Shaped Ternary Nanoparticles

Entropy and Non-Fourier Flux on Hydro-magnetic Flow Among Nonlinearly Radiated Porous Micro Walls Filled with Blood-Based Different Shaped Ternary Nanoparticles

Porous membranes integrated into electrochemical systems for bioanalysis

AbstractPorous membranes have emerged as promising platforms for bioanalysis because of their unique properties including high surface area, selective permeability, and compatibility with electrochemical techniques. This minireview presents an overview of the development and applications of porous membrane‐based electrochemical systems for bioanalysis. First, we discuss the existing fabrication methods for porous membranes. Next, we summarize electrochemical detection strategies for bioanalysis using porous membranes. Electrochemical biosensors and cell chips fabricated from porous membranes are discussed as well. Furthermore, porous micro‐/nanoneedle devices for bioapplications are described. Finally, the utilization of scanning electrochemical microscopy for cell analysis on porous membranes and electrochemiluminescence sensors is demonstrated. Future perspectives of the described membrane detection strategies and devices are outlined in each section. This work can help enhance the performance of porous membrane‐based electrochemical systems and expand the range of their potential applications.

Multiscale Micro‐Nano Hierarchical Porous Germanium with Self‐Adaptive Stress Dispersion for Highly Robust Lithium‐Ion Batteries Anode

AbstractThe manipulation of stress in high‐capacity microscale alloying anode materials, which undergo significant volumetric variation during cycling, is crucial prerequisite for improved their cycling capability. In this work, an innovative structural design strategy is proposed for scalable fabrication of a unique 3D highly porous micro structured germanium (Ge) featuring micro‐nano hierarchical architecture as viable anode for high‐performance lithium‐ion batteries (LIBs). The resultant micro‐sized Ge, consisting of interconnected nanoligaments and bicontinuous nanopores, is endowed with high activity, decreased Li+ diffusion distance and alleviated volume variation, appealing as an ideal platform for in‐depth understanding the relationship between structural design and stress evolution. Such a micro‐sized Ge being highly porous delivers a record high initial Coulombic efficiency of 92.5%, large volumetric capacity of 2,421 mAh cm−3 at 1.2 mA cm−2, exceptional rate capability (805.6 mAh g−1 at 10 Ag−1) and cycling stability (over 90% capacity retention after 1000 cycles even at 5 A g−1), largely outperforming the reported Ge‐based anodes for LIBs. Furthermore, its underlying Li storage mechanism and stress dispersion behavior are explicitly revealed by combined substantial in situ/ex situ experimental characterizations and theoretical computation. This work provides novel insights into the rational design of high‐performance and durable alloying anodes toward high‐energy LIBs.

Layered double hydroxide-based electrode materials derived from metal-organic frameworks: synthesis and applications in supercapacitors.

Metal-organic frameworks (MOFs) have emerged as promising electrode materials for supercapacitors (SCs) due to their highly porous structures, tunable chemical compositions, and diverse morphologies. However, their applications are hindered by low conductivity and poor cycling performance. A novel approach for resolving this issue involves the growth of layered double hydroxides (LDHs) using MOFs as efficient templates or precursors for electrode material preparation. This method effectively enhances the stability, electrical conductivity, and mass transport ability of MOFs. The MOF-derived LDH exhibits a well-defined porous micro-/nano-structure, facilitating the dispersion of active sites and preventing the aggregation of LDHs. Firstly, this paper introduces synthesis strategies for converting MOFs into LDHs. Subsequently, recent research progress in MOF-derived LDHs encompassing pristine LDH powders, LDH composites, and LDH-based arrays, along with their applications in SCs, is overviewed. Finally, the challenges associated with MOF-derived LDH electrode materials and potential solutions are discussed.

Thermal Insulation Properties of Delignified Balsa and Paulownia Wood “Foams” with Polylactic Acid Coverings

The energy-conserving performance of a building, normally realized by a variety of insulation materials, needs to be carefully considered, from the design to construction operations. Traditional mineral or chemically synthesized insulation materials are facing severer environment or health challenges. Hence, this work aims at developing an alternative thermal insulation material from wood. Two species, balsa and Paulownia, were chosen for their naturally low densities. Lignin and hemicellulose components were removed to create a “foamed” structure with more air induced. Polylactic acid (PLA) was applied to cover the delignified wood samples to further improve the hydrophobicity. The microstructure, physical properties, thermal conductivity and insulation properties of the treated wood samples were assessed. After lignin and hemicellulose removal, the original porous micro skeleton of balsa and Paulownia wood was retained, along with an increased porosity to 96.6% and 94%, respectively. Meanwhile, the thermal conductivity was successfully decreased by 22% to 0.053 W/(m·K) for balsa wood and by 27% to 0.067 W/(m·K) for Paulownia wood. PLA-covering treatment further enhanced the water resistance of the delignified wood samples without an evident change in the thermal conductivity. The above findings demonstrated the feasibility of applying delignified wood as a potential insulation material in modern construction operations, which may help set up a new pathway for a low-carbon and energy-saving construction industry.

Anti-osteoarthritis effects of injectable hyaluronic acid hydrogel loaded with platelet lysate and cerium oxide nanoparticle by regulating TNF-α: An in vitro model

The most prevalent type of joint illness is osteoarthritis, also known as OA. The inflammation of the joint is strongly linked to both the beginning and the progression of osteoarthritis. The use of hydrogels as an OA treatment has the potential to go beyond the administration of anti-inflammatory components to have an inherent immunomodulatory role. Platelet lysate (PL) contains a cocktail of growth factors that actively participates in cartilage repair. Moreover, cerium oxide-nanoparticles (CeO2-NPs) have been broadly studied owing to their powerful antioxidant properties and potential preventive and therapeutic effects against chronic diseases. The current study was designed to determine the effect and mechanism of injectable hyaluronic acid (HA) hydrogel loaded with PL and CeO2-NPs on OA. The results showed that the obtained PL and synthesized CeO2-NPs were effectively incorporated into HA hydrogel and the resultant hydrogel was injectable and have a porous micro structure with interconnected pores. The biological evaluation by qPCR revealed that the fabricated hydrogel exhibited a significantly increased expression of Col2 and Aggrecan (TNF-α-suppressed anabolic molecules) and decreased expression of Col10, Mmp13, Adamts5, and Adamts9 (TNF-α-activated catabolic molecules). Also, ELISA results confirmed this potent antioxidant activity of hydrogel and also increased the growth of chondrocytes over the culturing period.

Scalable Synthesis of a Porous Micro Si/Si-Ti Alloy Anode for Lithium-Ion Battery from Recovery of Titanium-Blast Furnace Slag.

The extensive utilization of Si-anode-based lithium-ion batteries faces obstacles due to their substantial volume expansion, limited intrinsic conductivity, and low initial Coulombic efficiency (ICE). In this study, we present a straightforward, cost-effective, yet scalable method for producing a porous micro Si/Si-Ti alloy anode. This method utilizes titanium-blast furnace slag (TBFS) as a raw material and combines aluminothermic reduction with acid etching. By adjusting the Al:TBFS ratio, the specific surface area of the material can be facilely tailored, ranging from 25.89 to 43.23 m2 g-1, enhancing the ICE from 78.2 to 85.5%. The incorporation of the Si-Ti alloy skeleton and porous structure contributes to the enhanced cyclic stability (capacity retention from 50.7 to 96.9%) and conductivity (Rct from 107.7 to 76.6 Ω). The Si/Si-Ti anode exhibits excellent electrochemical performance, including delivering a specific capacity of 1161 mAh g-1 at 200 mA g-1 after 200 cycles and 1112 mAh g-1 at 500 mA g-1 after 100 cycles, with an improved ICE of 81.2%. This study introduces a successful methodology for designing novel Si anodes from recycling waste materials, providing valuable insights for future advancements in this area.

A Novel Differential Quadrature Galerkin Method for Dynamic and Stability Behaviour of Bi-directional Functionally Graded Porous Micro Beams

The free vibration and buckling behaviours of 2D-FG porous microbeams are explored in this paper utilizing the Quasi-3D beam deformation theory based on the modified couple stress theory and a Differential Quadrature Galerkin Method (DQGM) systematically, as a combination of the Differential Quadrature Method (DQM) and the semi-analytical Galerkin method, which has used to reduce computational cost for problems in dynamics. The governing equations are obtained using the Lagrange’s principle. The mass and stiffness matrices are calculated using the weighting coefficient matrices given by the differential quadrature (DQ) and Gauss-Lobatto quadrature rules. The matrices are expressed in a similar form to that of the Differential Quadrature Method by introducing an interpolation basis on the element boundary of the Galerkin method. The sampling points are determined by the Gauss-Lobatto node method. The influence of the thickness-to-material length scale parameter (MLSP) on the nondimensional natural frequencies and nondimensional critical buckling loads of 2D-FG porous microbeams are investigated, along with the effects of the boundary condition, aspect ratio and gradient index. The results are validated with literature to establish the accuracy of the procedure described. This work will provide a numerical basis for the design of FG microstructures in the field of micromechanics. These results can be applied to the engineering design of porous FG microstructures.

In-situ construction of hierarchical NPO@CNTs derived from Ni-MOF as ultra-high energy storage electrode for battery-type supercapacitor

Owing to the poor electric conductivity and inferior cyclic stability of transition metal phosphates, it is an important challenge to develop MOF-derived transition metal phosphate electrode with open frame structures and high redox-active sites for superior conductivity, favorable chemical stability and enhanced charge storage capacity. Metal organic frameworks (MOFs) are the promising precursors/templates for the construction of porous micro- and nano-structured metal phosphates due to their adjustable structure and composition, abundant stratified pore structure and high specific surface area. However, the low conductivity of phosphates and even MOF-derived electrode often requires to be improved with a conductive network to enhance the overall energy density and cycle stability. Herein, three-dimensional interconnected hierarchical phosphorylated Ni-MOF (Ni2P2O7, NPO)@CNTs nanostructure were synthesized by using [email protected] as the sacrificing precursor in which CNTs not only acted as a conductive network but also provided rich nucleation sites for the anchoring of redox-active centers. The prepared [email protected] electrode achieved excellent electrochemical performance with an ultrahigh specific capacitance of 3237.6 F g−1 at 1 A g−1 and a specific capacitance retention of 67.1 % at 10 A g−1 and the assembled hybrid supercapacitor (HSC) device showed a maximum specific energy density of 41.9 Wh kg−1 at 750 W kg−1 and long cyclic lifespan with a capacitane retention of 91.0 % at 1 A g−1 after 5000 cycles.

Mechanical-Thermal Stability of Micro Composite Based Porous Carbon from Coconut Shell (<i>Cocoa nucifera</i>) Charcoal

Research on the mechanical thermal stability of micro-porous carbon-based micro composites with marine paint matrices has been carried out. Microporous carbon has the property of absorbing radar waves so it is very interesting to research and develop into a microwave shielding material synthesized from coconut shell (cocoa nucifera) by carbonization process at 600°C for 45 minutes. The molecular structure and phases of micro porous carbon were characterized using Fourier Transform Infrared (FTIR) and X-Ray Diffraction (XRD) with the results confirmed of micro carbon with reduced graphene oxide (rGO) phase. Furthermore, micro-composites made from porous micro carbon with marine paint as a binder were made using the wet mixing-casting method. Mechanical thermal testing was carried out by means of a shear test at a temperature range of 30 – 70°C using a Dynamics Mechanical Analysis (DMA) tool. The test results showed that the value of the storage modulus of porous micro carbon composites was 1.653 MPa, 10.196 MPa, 13.068 MPa, 118.567 MPa, respectively. The value of the composite storage modulus increases with increasing concentration of porous micro carbon with an optimum value of mechanical thermal stability at a composition of 70:30 %wt. The results of mechanical thermal testing showed that porous micro carbon with rGO phase from coconut shells has the potential to be used as an anti-radar shielding material. 068 MPa, 118.567 MPa. The value of the composite storage modulus increases with increasing concentration of porous micro carbon with an optimum value of mechanical thermal stability at a composition of 70:30 %wt. The results of mechanical thermal testing showed that porous micro carbon with rGO phase from coconut shells has the potential to be used as an anti-radar shielding material. 068 MPa, 118.567 MPa. The value of the composite storage modulus increases with increasing concentration of porous micro carbon with an optimum value of mechanical thermal stability at a composition of 70:30 %wt. The results of mechanical thermal testing showed that porous micro carbon with rGO phase from coconut shells has the potential to be used as an anti-radar shielding material.

Preparation of Porous Silver Nanowires‐Melamine Formaldehyde Hybrid Composite Materials and Their Electromagnetic Shielding and Flame‐Retardant Properties

Along with the booming development of communication technology and electronic equipment, higher requirements of flame‐retardant and EMI shielding performances for electromagnetic interference (EMI) shielding materials are put forward. Herein, the ultralight and porous silver nanowires (AgNWs)‐melamine formaldehyde (MF) hybrid composite with unique micro‐/nanostructure is developed by a facile dip‐coating method, which uses the AgNWs as 1D conductive coating and MF foam (MF foam) as 3D skeleton template. Benefiting from the unique porous micro‐/nanostructure, the resultant hybrid composite displays low density, excellent EMI shielding performances, and superior flame‐retardant property. The EMI shielding effectiveness (SE) and specific EMI SE (SSEt) of the hybrid composite in X‐band (8.2–12.4 GHz) can be up to 77 dB and 26971.4 dB cm−2 g−1, respectively. At the same time, the hybrid composite also passes the vertical burning test and shows an increased LOI value of 40.6%. The combination of flame‐retardant and EMI shielding performances for EMI shielding materials makes the AgNWs‐MF hybrid composite great application potential in civil and military fields. This work provides a new guide for the design of multifunctional high‐performance EMI shielding materials.

Moving Load Analysis of Laminated Porous Micro Beams Resting on Elastic Foundation

This research highlights dynamic displacements of laminated porous micro beams resting on elastic foundation under moving load. In the constituted equation of laminated micro scaled beam, the modified coupled stress theory is used in order to determine the size effect. Each layer is considered as identical and porosity distribution and assumed as uniform. Lagrange technique is applied in achieving governing equations, and Ritz method within algebraic polynomials is used for solution. For dynamic solution steps, Newmark average acceleration method is used within time domain. Influences of porosity coefficients, length scale parameter, foundation parameter, order of laminas, fiber orientation angles on dynamically deflections of laminated micro beam are investigated.

Different amount of carboxyl-aldehyde fractionated nanofibril cellulose and main characteristics of chitosan, gelatin, alginate added composites

In this research, two different types of nanofibrillated celluloses (NFCs) having different amounts of aldehyde and carboxyl groups were mixed with chitosan (CH), gelatin (GL), and alginate (AL) with different mixing ratios to produce biocomposite aerogels. There was no related study in the literature about producing aerogels with the addition of NC and mentioning biopolymers in addition to the effect of carboxyl and aldehyde fraction of the main matrix NC on composite properties. For this purpose, the main aim of this study was to investigate how carboxyl and aldehyde groups affect the basic characteristics of NFC-biopolymer based materials addition to efficiency of biopolymer amount in main matrix. Even after preparing homogenous NC-biopolymer compositions at 1 % concentration with varied proportions (75 %–25 %, 50 %–50 %, 25 %–75 %, 100 %), aerogels were still made using the fundamentally easy lyophilization procedure. Porosity values for NC-Chitosan (NC/CH) based aerogels range from 97.85 to 99.84 %, whereas those made from NC-Gelatin (NC/GL) and NC-Alginate (NC-AL) have values of 99.2–99.8 % and 98.47 to 99.7 %, respectively. In addition, densities were determined in the range of 0.01 g/cm3 for both NC-CH and NC-GL composites, but higher values were obtained in ranged between 0.01 and 0.03 g/cm3 for NC-AL samples. The crystallinity index values showed a decreasing trend with the addition of biopolymers into NC composition. SEM images showed that all materials have a porous micro structure with different size pores and homogenous surface topography. As a result of the specified tests, these materials can be used in many different industrial applications, such as dust collectors, liquid adsorbers, specific material for packaging and medical materials.

Three-dimensional hierarchically porous micro sponge-ball comprising anatase TiO2 nanodots and nitrogen-doped graphitic carbon as anodes for ultra-stable lithium-ion batteries

Hierarchically porous three-dimensional micro sponge-balls comprising highly conductive nitrogen-doped graphitic carbon (NGC) and anatase-type TiO2 nanodots (TiO2@NGC MSB) are synthesized using spray pyrolysis technique followed by heat treatment. The as-sprayed powders obtained after spray pyrolysis consist of polystyrene (PS) nanobeads-derived macropores and anatase TiO2 nanodots embedded in an amorphous carbon (AC)-NGC carbon matrix (TiO2@NGC-AC MSB). The subsequent heat treatment of the as-sprayed powders at 300 °C resulted in the formation of additional micropores by selective removal of the AC into gaseous products to form TiO2@NGC MSB. The obtained hierarchically porous and highly conductive architecture guarantees effective electrolyte infiltration inside the electrode, enhanced Li-ion diffusion, and faster charge transfer during the redox reactions. Benefited from the structural merits, the TiO2@NGC MSB anode exhibits remarkable electrochemical performance compared to those of TiO2@NGC-AC MSB and filled-type TiO2 anodes. A reasonable discharge capacity of 105 mA h g−1 at a high current density of 10.0 A g−1 and exceptional cycling performance (219 mA h g−1 with 0.0006 % decay rate after 2000 cycles at 2.0 A g−1 and 160 mA h g−1 with 0.003 % decay rate after 5000 cycles at 3.0 A g−1) are obtained.

Spray pyrolyzed hydrophilic nickel oxide electrodes with nano-granular morphology for a symmetric supercapacitor device

The symmetric supercapacitor device is efficiently invented using two identical sprayed nickel oxide thin film electrodes equipped via an aqueous path. Firstly, we did a comparative study of structural, morphological and electrochemical characterizations of nickel oxide electrodes which are prepared by varying concentrations of the precursors (0.2, 0.4, 0.6, 0.8 and 1.0 M and renamed according to their concentration as AC (Aqueous Concentration) AC-1, AC-2, AC-3, AC-4 and AC-5 respectively). XRD patterns of all electrodes confirm cubic crystal structure. The highest value of specific capacitance of NiO@AC-4 (0.8 M) electrode is 256.32 Fg−1 at 0.002 Vs−1 which is the maximum among all electrodes. The specific energy and specific power of the AC-4 electrode at 0.002 Acm−1 are 29.08 Whkg−1 and 3.06 kWkg−1 respectively. NiO@AC-4 electrode shows 69.42% retention in capacitance value after 5000 cyclic voltammetric cycles. The fabricated device parades specific capacitance (SC) 92.81 Fg−1 at 0.002 Vs−1. The wettability study depicts the hydrophilic nature of all electrodes (except the NiO@AC-1 electrode). As concentration increases morphology of the prepared electrodes changes from impenetrable to porous micro globules. SEAD pattern rings and XPS investigation are well matched with XRD analysis.

Plasmonic porous micro- and nano-materials based on Au/Ag nanostructures developed for photothermal cancer therapy: challenges in clinicalization.

Photothermal therapy (PTT) has developed in recent decades as a relatively safe method for the treatment of cancers. Recently, various species of gold and silver (Au and Ag) nanostructures have been developed and investigated to achieve PTT due to their highly localized surface plasmon resonance (LSPR) effect. Concisely, the collective oscillation of electrons on the surface of Au and Ag nanostructures upon exposure to a specific wavelength (depending on their size and shape) and further plasmonic resonance leads to the heating of the surface of these particles. Hence, porous species can be equipped with tiny plasmonic ingredients that add plasmonic properties to therapeutic cargoes. In this case, a precise review of the recent achievements is very important to figure out to what extent plasmonic photothermal therapy (PPTT) by Au/Ag-based plasmonic porous nanomedicines successfully treated cancers with satisfactory biosafety. Herein, we classify the various species of LSPR-active micro- and nano-materials. Moreover, the routes for the preparation of Ag/Au-plasmonic porous cargoes and related bench assessments are carefully reviewed. Finally, as the main aim of this study, principal requirements for the clinicalization of Ag/Au-plasmonic porous cargoes and their further challenges are discussed, which are critical for specialists in this field.

Effect of ammonia catalyst on the morphological structures of sol–gel‐derived bioactive glass 58S for dental application

AbstractAimTo determine the effect of ammonia on the surface morphology and chemical properties of sol–gel‐derived bioactive glass 58S powders for dental application.Materials and MethodsBioactive glass (BG) 58S powder was synthesized using a sol–gel method. Hydrochloric acid solution was mixed with ethanol, distilled water, and tetraethyl orthosilicate for 30 min, followed by the addition of triethyl phosphate and calcium nitrate tetrahydrate. The mixture was stirred until the particles were completely dissolved. Three different groups were prepared: BG‐1 (no ammonia added), BG‐2 (3 ml of ammonia added), and BG‐3 (5 ml of ammonia added). The gel was then aged and calcined. The solidified gel was crushed until the powder passed through a 200‐μm sieve. Subsequently, the surface morphology was evaluated using a scanning electron microscopy, whereas the chemical composition was assessed using a Fourier transform infrared spectroscopy (FTIR).ResultsBG‐2 and BG‐3 exhibited small‐sized cluster grains and a more porous micro‐ or nano‐structures. The crystallinity of the BG powder and its surface porosity increased with increased ammonia. The average microparticle sizes of the BG‐1, BG‐2, and BG‐3 were 196 ± 31, 45 ± 21, and 20 ± 9 μm, respectively, with nano‐grains in BG‐2 and BG‐3 showed strong tendency of agglomeration. FTIR verified the existence of a silica network‐based glass, with the Si–O–Si functional group visible in the spectrum of all groups.ConclusionThe addition of ammonia as catalyst during the hydrolysis process resulted in small glassy grains and more porous surfaces of BG 58S, which is anticipated to promote greater bioactivity.