Silicon-based Materials Research Articles

Design of Silicon-Based Anode Materials for High Energy Density Li-Ion Batteries

Compared to other types of batteries, lithium batteries have an extremely high energy density, which means they can store more energy while maintaining a smaller size and weight. The ideal electrode material must have a high lithium ion capacity to store many lithium ions. In addition, the electrode material must have good electronic conductivity to promote lithium ions' rapid entry and exit. However, traditional carbon materials have limited theoretical specific capacity, and the transmission of lithium-ion batteries in traditional materials is limited, resulting in a significant decrease in capacity. Silicon has a theoretical capacity of up to 4200mAh/g, more than ten times the capacity of commercial graphite negative electrodes. In addition, silicon and lithium can undergo alloying reactions to form Li Si alloys, which helps improve the material's specific capacity. This article first summarizes the advantages of electric vehicles and lithium-ion batteries. Then, the benefits and challenges of using silicon-based materials as negative electrodes for lithium-ion batteries were elaborated in detail, and finally, the prospects of silicon-based materials in lithium-ion battery applications were summarized. This article has reference significance in improving the energy density of lithium-ion batteries.

Progress in the application of silicon-based materials in lithium-ion batteries anodes

From the battery that powers the remote control to the battery that powers electric cars, lithium-ion batteries (LIBs) are a crucial component of contemporary energy storage. The large theoretical capacity of silicon anodes provides significant benefits inside LIBs. However, the main issue with the conventional silicon bulk anode is its considerable volume expansion, which forms an unstable Solid Electrolyte Interface (SEI) layer during the charge and discharge process and severely reduces battery performance and lifespan. Therefore, to solve these issues, researchers have explored multiple improved silicon anodes, three of which are mentioned in this essay. Firstly, the researchers delve into the usage of nanotechnology. When manipulating silicon particles at the nano-scale, the nano-silicon can mitigate the volume expansion, improving the reaction kinetics. Then, a composite of carbon and silicon is proposed, combining silicon's high capacitance and carbon's high conductivity. After that is the silicon-metal composite, which utilizes metals' mechanical strength and conductivity to stabilize Si anodes further and improve thermal stability. Overall, the significance of this study lies in the exploration of the application of silicon anodes in LIBs, highlighting the potential of these composite materials and advanced technology, which may help guide the future exploration of better silicon anodes.

Bioinspired skin-like in vitro model for investigating catheter-related bloodstream infections

Intravenous (IV) catheter-related bloodstream infections (CRBSIs) cause significant risks in healthcare, necessitating advancements in catheter design and materials. This study investigates the effectiveness of Ecoflex, a silicone-based material, in studying CRBSIs through the development of skin-like replicas that mimic human skin properties for use in wearable sensing devices. We characterized the replica’s bioinspired surface roughness, wettability, bacterial adhesion, and mechanical properties and validated its performance using in vitro IV simulation. The results demonstrated that the bioinspired model replicates human skin textures with less than 7.5% error for surface roughness ranging from 0.05 μm to 6.3 μm. Wettability tests revealed that the artificial sebum application significantly reduced the static contact angles for deionized water and artificial sweat. Comprehensive mechanical testing revealed material high elasticity and resilience, suitable for dynamic biomedical applications. Bacterial adhesion studies using Staphylococcus epidermidis showed varying adhesion patterns influenced by surface roughness, highlighting the potential for material texture to impact infection risk. In IV therapy simulations, we observed bacterial growth dynamics over the incubation period. Our findings suggest that Ecoflex-based skin-like replicas can serve as a valuable tool for developing and testing new catheters, while the potential for use in other medical innovation devices, including wearable sensing devices, ultimately contributes to improved patient outcomes and infection control strategies.

Preparation of high strength and rigidity carbon layer on SiO material surface by dynamic CVD method using gas carbon source C2H2

The main issue in the application of silicon-based negative electrode materials is the inevitable volume expansion, leading to negative electrode material fracture, which severely impacts the performance of batteries. This study employed Chemical Vapor Deposition (CVD) (C2H2@SiO), solid-phase coating method (Pitch@SiO), and liquid-phase coating method (RGFQ@SiO) to coat the surface of SiO materials with a dense amorphous carbon structure. Material property analysis revealed that C2H2@SiO has a relatively small specific surface area (1.8 m2 g−1) and surface carbon increment (2.4 %). It exhibited high reversible specific capacity (1563.4 mAh g−1), high initial Coulombic efficiency (81.45 %), and low volume expansion rate (9.3 %). Mechanical performance testing indicated that the surface carbon layer Young's modulus of C2H2@SiO was the highest (35 GPa), suggesting that using the CVD method to obtain a dense carbon layer can enhance the structural strength of the material. Based on the electrochemical-mechanical coupling theory simulation analysis of the stress during the charge-discharge process of electrode materials, the evolution of concentration and stress field during lithium insertion process was obtained, showing that the coating can further improve the electrochemical and mechanical performance of the negative electrode materials effectively. Additionally, the negative electrode sheets fabricated using sample C2H2@SiO were assembled into 18650 cylindrical batteries, exhibiting excellent cycling performance in 1000 cycles at 25 °C with a capacity retention rate of 85.7 %, along with good rate capability and high/low-temperature performance. The conclusions of this study provide certain guidance for the design and optimization of negative electrode materials for battery electrodes.

Biological small molecule interface-modification fostering resilient interfacial chemistry for silicon-based anodes

Silicon-based materials, particularly at the microscale, are prone to rapid capacity fade due to substantial volume fluctuations during the charge-discharge cycles, significantly impeding their commercial viability. Constructing a stable solid electrolyte interface (SEI) is an effective means to improve the performances of silicon-based anodes. Here small biomolecules, tryptophan (Trp) and phytic acid (PA), are introduced as interface modifiers to optimize the interfacial chemistry of micron-silicon anodes. By engaging in the SEI formation process, these small biomolecules effectively regulate the chemical composition and mechanical properties of the formed SEI, fostering a more cohesive and durable interface. The simultaneous addition of PA and Trp has been observed to yield a synergistic effect, creating a tightly bonded and resilient SEI that confers markedly improved battery performances upon the co-modified micron silicon anodes. Density functional theory calculations reveal charge interactions between these small biomolecules and silicon particles, facilitating effective adsorption onto the silicon surface. Simultaneous adsorption of Trp and PA on silicon surface can significantly enhance adsorption strength, providing a compelling explanation for the observed synergistic effect of Trp and PA co-modification.

Micron silicon-oxide-carbon coated with TiOx(OH)y layer as better performance anode for lithium-ion batteries

Micron-silicon based material is a promising anode material for high performance lithium batteries due to its ultra-high specific capacity. However, the volume expansion exceeds 300 % during charging and discharging, resulting in the collapse of the electrode structure and a rapid decline in electrochemical performance. Coating the surface of silicon-based materials with flexible ionic conductors is an effective method to maintain their high capacity and suppress swelling. Here, to further improve the electrochemical performance of silicon-based materials, we have deposited a titanate-type ionic conductor layer on a micron-sized silicon-carbon oxide (SiOX-C) material to synthesize the SiOX-C@TiOx(OH)y material. The TiOx(OH)y layer not only exhibits the elastic properties of a superpolymer to mitigate swelling strain, but also has a fast capacitance effect to improve its rate performance. In addition, the interfacial charge transport of SiOX-C@TiOx(OH)y is enhanced due to the structural diversity of the TiOx(OH)y layer. For the above mechanisms, the SiOX-C@TiOx(OH)y has a specific capacity of 278.3 mAh g−1 under high current of 3500 mA g−1. Meanwhile, the SiOX-C@TiOx(OH)y with the capacity retention of 67 % is achieved at 2000 mA g−1 after 100 cycles.

Structures, simulated photoelectron spectroscopy, and electronic properties of CuASix(A = Sc, Cu, x ≤ 13) clusters: Relatively stable neutral pentagonal bipyramid structures of CuASi5

Structural design and optimization, simulated photoelectron spectroscopy, electronic properties and chemical bond analysis of CuASix(A = Sc, Cu, x ≤ 13) clusters were systematically studied using the PBE scheme to integrate with global search program of ABCluster. Firstly, neutral MS (the most stable structures) of CuASi5 of the basic 1 + 5 + 1 structures (1 metal + 5 silicons + 1 metal atoms) can be found as the basic units for assembling more lager clusters under the condition of neglecting distortions and minor changes. If the Cu atoms in Cu2Six(x ≤ 13) systems was replaced by one Sc atom, the geometries of MS will be reconstructed. Compared with the wheel geometries of Cu2Si12 and Cu2Si13, CuScSi12 and CuScSi13 clusters belong to near-wheel geometries with peripheral metal atoms. The neutral CuScSi5 and Cu2Si5 clusters possess relatively higher stability in all of cluster sizes. A combination of NPA analysis of CuASi5, sp of the Cu atom and spd of the Sc atom hybridizations were crucial to the chemical bonds of A–Si in the neutral CuASi5 clusters. In view of the higher SED value of the Cu2Si5 molecule, chemical bond analysis was carried out using MO, HLg and AdNDP analysis. 18 localized bonds and four delocalized bonds can play a positive role for the relative stabilities of neutral pentagonal bipyramid structures of Cu2Si5. Thus, the Cu2Si5 cluster with a lager HLg(1.80 eV) may be a good candidate for the basic unit of silicon-based semiconductor material assembly.

Exploration of self-crosslinking induced surface modification using APTES on the PA RO membrane for excellent anti-fouling performance

The physicochemical properties of the polyamide reverse osmosis (PA RO) membrane surface play a crucial role in membrane fouling. In this work, a silicon-based material, γ-Aminopropyl triethoxysilane (APTES), was incorporated onto the PA membrane surface by self-crosslinking induced surface modification to improve its antifouling properties. FTIR and XPS analyses reveal that APTES primarily bonded to the pristine PA membrane via amidation between –NH2 groups in APTES and residual –COCl groups on the membrane surface, and then combined with each other to form Si–O–Si groups (even Si–O–Si networks). The incorporation of APTES reduces the membrane surface energy and roughness, and the surface potential of the membranes can be adjusted by varying the APTES addition. Meanwhile, the pure water permeance of the APTES-PA membrane reached ~3.77 LMH/bar while maintaining a NaCl rejection of ~98.65%. Additionally, although the negative charge of the APTES-PA (M0.15) membrane increases, the antifouling against electropositive small molecular foulants is enhanced, mainly due to the low-surface-energy of the APTES-modified layer. Furthermore, the stability of the APTES-modified layer in the presence of electronegative small molecular foulants with strong decontamination capabilities can be reinforced by a simple high-temperature heat treatment. Broadly speaking, surface modification of the PA RO membrane by APTES combining grafting with self-crosslinking induced method is beneficial for its anti-fouling and reuse.

Modulation of Free Carbon Structures in Polysiloxane-Derived Ceramics for Anode Materials in Lithium-Ion Batteries.

Polymer-derived silicon oxycarbide (SiOC) ceramics have garnered significant attention as novel silicon-based anode materials. However, the low conductivity of SiOC ceramics is a limiting factor, reducing both their rate capability and cycling stability. Therefore, controlling the free carbon content and its degree of graphitization within SiOC is crucial for determining battery performance. In this study, we regulated the free carbon content using divinylbenzene (DVB) and controlled the graphitization of free carbon with the transition metal iron (Fe). Through a simple pyrolysis process, we synthesized SiOC ceramic materials (CF) and investigated the impact of Fe-induced changes in the carbon phase and the amorphous SiOC phase on the comprehensive electrochemical performance. The results demonstrated that increasing the DVB content in the SiOC precursor enhanced the free carbon content, while the addition of Fe promoted the graphitization of free carbon and induced the formation of carbon nanotubes (CNTs). The electrochemical performance results showed that the CF electrode material exhibited a high reversible capacity of approximately 1154.05 mAh g-1 at a low current density of 100 mA g-1 and maintained good rate capability and cycling stability after 1000 cycles at a high current density of 2000 mA g-1.

Preparation of Si/TiSi2 as high-performance anode material for lithium-ion batteries by molten salt electrolysis

The photovoltaic industry has generated a large amount of silicon cutting waste (SiCW), whose disposal presents an urgent environmental issue. In this study, micron-sized flaky silicon cutting waste was transformed into silicon nanowires, and Si/TiSi2 nanocomposites were synthesized through molten salt electrolysis using photovoltaic SiCW and TiO2 as precursors. Lithium-ion batteries using the resulting composites as an anode exhibited an initial discharge specific capacity of 1936.1 mAh g⁻¹ and an initial Coulombic efficiency (ICE) of 83.99 %. After 200 cycles, its reversible specific capacity reached 1133.8 mAh g⁻¹, surpassing that of the molten salt electrolytic pre-oxidized SiCW (535.5 mAh g⁻¹) and untreated SiCW (385.0 mAh g⁻¹). This study presents a novel approach for modifying silicon-based anode materials while offering a sustainable and environmentally friendly method for recycling photovoltaic silicon waste.

Reinvigorating Photo-Activated R-Alkoxysilanes Containing 2-Nitrobenzyl Protecting Groups as Stable Precursors for Photo-Driven Si-O Bond Formation in Polymerization and Surface Modification.

This study aimed to revitalize silicon-based sol-gel chemistry methodologies utilizing photoprotected R-alkoxysilanes to control the synthesis of unique silicon-based materials. We have investigated the synthesis, characterization, light-induced deprotection, and subsequent polymerization/surface functionalization through the use of 2-nitrobenzyloxy-based photoremovable protecting groups (PPGs) as alkoxy reactive groups on ethyl and phenyl (R x -(alkoxy) y silanes, with x = 0-3 and y = 1-3). The photochemical dynamics, relative efficiencies, and kinetics of the novel alkoxysilane-based PPGs were thoroughly investigated using UV light irradiation by NMR and UV/vis methods. We then explored the tin-catalyzed coupling of photodeprotected products (R x -silanols) to form polymers/oligomers. We have found that photoenabled removal of PPGs and conversion to silanols from all silane systems studied is achieved. Furthermore, these deprotected species are polymerizable into siloxanes and effectively used as light-controlled surface modifiers with masking techniques of which proof-of-concept examples are given, enabling promising application as photolithographic reagents.

Control of N/P ratios and cut-off voltage for Silicon-Based Li-ion batteries

High-energy density and unwavering safety standards form the cornerstone of new energy vehicle development, necessitating the design of power batteries that seamlessly integrate these critical qualities. Key to this endeavor is the enhancement of energy density at the architectural level, focusing on the optimization of the N/P ratio—a move that demands a holistic evaluation extending beyond mere comparisons of cathode and anode capacities to include initial efficiency, and both reversible and irreversible capacities. Departing from traditional N/P ratio designs requires meticulous optimization. This research introduces a novel N/P ratio design methodology, termed the “Water Cup Model”, for lithium-ion batteries (LIBs), effectively addressing capacity loss issues endemic to conventional designs. This approach, under consistent cathode material and areal capacity conditions, increases the batteries’ specific energy by approximately 5 Wh/kg, without compromising safety. Further innovation is achieved by incorporating a voltage regulation coefficient, λ, allowing for precise adjustment of the cut-off discharge voltage and facilitating the selection of high-performance silicon-based anode materials. Comparative assessments of energy density and cycling performance affirm the superiority of our optimized N/P ratio strategy against conventional methods. This strategy’s core lies in its capacity to significantly boost energy density without extensive modifications to the battery’s internal makeup, relying solely on the precise management of the N/P ratio to ensure safety is not compromised by energy density enhancements. This seminal work lays down a cost-effective, robust framework for advancing high-performance LIB technology, contributing pivotal insights to the field.

Silicon/graphite/amorphous carbon composites as anode materials for lithium-ion battery with enhanced electrochemical performances

Silicon has emerged as one of the most promising anode materials for next-generation lithium-ion batteries due to its exceptional specific capacity and abundant resources. However, its widespread application is hindered by structural deformability and low intrinsic conductivity. By strategically integrating a conductive carbon matrix with silicon, it becomes feasible and efficient to enhance the electrical conductivity of silicon and accommodate the stress-induced volume expansion during battery operation. In this study, a series of silicon/graphite/amorphous carbon (Si/G/C) composites were prepared using mechanical milling and carbothermal reduction. The study focused on two main aspects: the effect of the ratio of micro-sized silicon to flake graphite on the properties of the composite and the compatibility of different-scale silicon particles (micro-sized silicon and nano-sized silicon) and different kinds of natural graphite (flake graphite and cryptocrystalline graphite). The results reveal that when micro-sized silicon and flake graphite are combined, the graphite is fragmented more thoroughly, resulting in smoother surfaces and reduced aggregation of secondary particles. The composites with a mass ratio of 7:3 micro-sized silicon to flake graphite have the smallest specific surface area and pore size, homogeneous distribution, and stable structure. This exceptional carbon-to-silicon ratio endows the Si/G/C composite with rapid reaction kinetics, enabling a specific discharge capacity of 854.1 mAh g-1 after 200 cycles at 1A g-1. The findings offer valuable insights into the design and optimization of silicon-based anode materials for next-generation lithium-ion batteries.

Evaluation of Tensile Bond Strength of Nanoparticle Reinforced Soft Liner Materials: A Pilot Study

OBJECTIVE: The aim of this study is to evaluate the tensile bond strength between polymethyl methacrylate (PMMA) surfaces and autopolymerized silicon-based soft lining materials with 1% w/w Titanium dioxide (TiO2) and Hydroxyapatite (HA) nanoparticles added. MATERIALS AND METHODS: For the tensile test, 60 pieces of acrylic (Meliodent, Bayer Dental, Newbury, England) samples of 30 × 10 × 10 mm3 dimensions were prepared using metal molds. Acrylic surfaces were sanded with silicon carbide sandpapers of 500, 1000, 1500, and 2000 grids to ensure standardization. After the samples were placed back in the metal mold, adhesive (Detax, Germany) was applied to the surfaces that would come into contact with the soft lining. Soft lining materials (Mollosil, Detax, Ettlingen, Germany) to which 1% by weight TiO2 and 1% HA nanoparticles were added were polymerized by placing them between two acrylic blocks. For the tensile test, a total of 30 samples were obtained, with 10 samples in each group (n=10). The specimens were placed on the holder end of the universal test device and force was applied until failure occurred. RESULTS: The tensile bond strength (0,86 ± 0,21 MPa) in the TiO2 nanoparticle-added group was found to be significantly higher than the control group (0,65 ± 0,14 MPa) (p<0.05). There is no significant difference between the control group and the HA nanoparticle-added group (0.65 ± 0.1 MPa) (p˃0.05). CONCLUSION: It was observed that the addition of nanoparticles increased the tensile strength. However, further studies are needed to evaluate the effect of nanoparticle addition on other mechanical and physical properties of soft liners.

A novel approach to synthesize micrometer-sized porous Si/SiOx@C with internally and externally interweaved CNTs as a high performance anode for lithium-ion batteries

Silicon-based materials are prospective anodes because of the high capability of lithium (Li) storage, but the large volumetric expansion seriously destroys the integrity of the electrodes and further results in unsatisfactory cycling performance. Reasonable structure design based on low-cost nano silicon (Si) prepared by an feasible method is still an enormous challenge. Herein, the carbon-coated and cross-linked carbon nanotube/porous-Si/SiOx microspheres (CNT/SFDP-Si/SiOx@C) are firstly synthesized by combining an inverse water-in-oil microemulsion approach with magnesiothermic reduction. One high value-added route for utilizing silica fume as the precursor to form nano silicon is provided. The collaborative strategy via wired CNTs network, porous-Si/SiOx flexible matrix, and carbon coating is employed to keep the integrity and stability of electrode structure. Benefiting from the synergistic effect of the flexibility of CNTs network, protection of outer carbon shell, doping of diverse nitrogen (N) species, and accommodation of porous-Si/SiOx, CNT/SFDP-Si/SiOx@C exhibits excellent electrochemical performance. The long cycling lifespan with a reversible capacity of 675.8 mAh g−1 after 1000 cycles at 2 A g−1, a slight decay rate per cycle of 0.018 %, and a high-rate performance are simultaneously obtained. The prelithiated LiFePO4||CNT/SFDP-Si/SiOx@C full cell is also assembled, showing the reversible capacity of 129.4 mAh g−1 at 0.2C.

Self-assembled Si-based anode combined with electrostatic spinning method to realize high-performance lithium-ion batteries

Addressing the volume expansion when silicon and metal oxides alone are used as anode materials for lithium-ion batteries. This study used a simple self-assembly method and electrostatic spinning technique to prepare silicon@copper oxide@carbon nanofibres (CNFs) anodes with dual modification. The high rigidity of metal oxide CuO and the excellent cycling stability of CNFs effectively reduce the buildup of silicon particles, alleviate the volume expansion effect, and improve the electrical conductivity, which leads to better cycling stability and larger specific capacity of lithium-ion batteries. An excellent reversible specific capacity of 748.5 mAh g‐1−1 was observed after 800 cycles at a high current density of 1 A g−1. In addition, the surface of Si@CuO@CNFs electrodes remains smooth and undamaged after 800 cycles, and the increase in cross-sectional thickness is about 68 %, which is significantly smaller than the 300 % increase in cross-sectional thickness of pure Si anode and effectively improves the specific capacity of Li-ion batteries. This research optimizes the design of silicon-based anode materials with simple and mature process technology, which makes an indispensable contribution to developing high-efficiency, long-life, and environmentally friendly lithium-ion batteries. The easy availability and non-polluting nature of the materials used also effectively reduce the reliance on rare or expensive elements, minimize the production process's environmental impact, and vigorously promote the global energy transition and low-carbon green development strategy.

Fabrication and Characterization of Nanocrystalline and Nanotwinned Cu Foils By Electrodeposition

Because of the rise of electric vehicles, laptops, and smartphones in recent years, lithium-ion batteries play an important role in powering these electronic devices. As users become more attentive to battery lifespan and performance optimization for prolonged product utility, the selection of battery materials gains paramount significance. Copper, an integral conductor material within electronic devices, specifically functions as the anode current collector in lithium-ion batteries (LIBs). The anode electrode comprises a copper foil substrate coated with active materials, typically encompassing carbon-based materials and silicon-based materials. Although carbon-based materials, such as graphite, currently dominate the market, their relatively lower capacity prompts consideration of silicon-based materials as possessing substantial developmental potential.Nevertheless, silicon-based materials undergo volumetric expansion during charge and discharge processes, inducing pronounced swelling that may exert compressive forces on the copper foil, thereby elevating the risk of battery rupture. Consequently, the copper foil necessitates a requisite degree of strength to withstand these volumetric variations. Traditionally, copper foil fabrication relies on rolling techniques; however, it is hard to produce rolled Cu with thickness less than 10 mm. Therefore, electroplated copper foils have gradually emerged as the prevailing method in recent years. The purpose of strengthening is achieved by grain refinement, adding other metal impurities, and other strengthening methods. which causes the electrical conductivity to reduce. Nevertheless, nano-twinned copper can simultaneously increase the strength and avoid the problem of electrical conductivity decline. Nano-twinned copper is known to have high mechanical strength, good thermal stability, and resistance to electromigration.In this study, we employed the rotary electroplating technique to fabricate high-strength nanotwinned copper (NT-Cu) foils. By adjusting electroplating conditions through the incorporation of additives, we investigated the mechanical properties of copper foils. Copper foils electroplated at room temperature exhibited an ultimate tensile strength (UTS) of approximately 830 MPa and a yield strength (YS) of approximately 540 MPa. Compared with the regular copper foil plated under same condition, the UTS is increased by 70%, and the YS is increased by 50%. Moreover, the electroplated NT-Cu foil demonstrated good thermal stability, with the ultimate tensile strength decrease of only 1.54% following annealing for 1 hour at 100°C in a vacuum environment. After an annealing process at 200°C for 1 hour in a vacuum environment, the ultimate tensile strength decreased by approximately 8.74%.Additionally, electroplating experiments were conducted under both low and high-temperature conditions. The results revealed that copper foils electroplated at a low temperature of 10°C and low current density attained an ultimate tensile strength of 870 MPa, coupled with a yield strength of 560 MPa. In a high-temperature environment of 35°C, under high current density electroplating, the copper foils achieved an ultimate tensile strength of 845 MPa, reaching a yield strength of 540 MPa. These copper foils exhibited a fine-grained and nano-twinned microstructure, characterized by grains with dimensions less than 100 nm. Figure 1

(Digital Presentation) Investigation of the Damage of Focus Ion Beam (FIB) on Nanocrystals Formed in Terbium-Doped Silicon Oxide Thin Films

Terbium-doped oxygen-rich silicon oxide (ORSO:Tb) thin films were fabricated using Integrated magnetron sputtering and electron cyclotron plasma-enhanced chemical vapor deposition (IMS ECR-PECVD) method. To investigate damage from focus ion beam (a comparison is made between mechanical and FIB methods measurements, which did not reveal crystal damage induced by FIB.Silicon-based thin films are fundamental materials in electronics and photonics, and doping is a common method to enhance silicon-based thin film’s luminescence. Terbium (Tb), characterized by well-defined emission lines, ranging from 400 to 620 nm (green emission), provides compelling reasons for using Tb as a dopant in silicon-based thin films (1).TEM is a method employed for studying. Preparation methods are required to make a TEM sample that is transparent to the electron beam (with a thickness of approximately 100 to 200 nm) (2). While conventional techniques, like electrolytic polishing and mechanical milling, are commonly used for preparing TEM samples, they fall short of achieving the precise preparation of a TEM sample in a specific area of interest with high spatial resolution.FIB has been used for preparing TEM specimens, which is fast and reliable. By scanning the beam across the cross-section, it becomes possible to reduce the thickness of the sample to prepare it for TEM (4)(5). The primary issue is due to the impact of ion beams accelerated to high energy therefore, examination effect of FIB on structure is important. Damages resulting from using FIB have mainly been studied on Silicon-based materials (6)(7)(8).In this paper, Tb-doped silicon oxide (oxygen-rich) thin film deposited by IMS ECR-PECVD offers a more uniform distribution and well-controlled rare-earth doping (9). To investigate the damages induced in the preparation process, ORSO:Tb annealed at 1200 °C was divided into two parts, and then a comparison between the mechanical and FIB preparations for TEM samples was made.ORSO:Tb were fabricated using an IMS ECR-PECVD system, employing 2 sccm SiH4 at 30% Ar and 28 sccm O2 at 10% as silicon (Si) and oxygen (O) precursors. These gas sources were delivered to the ECR chamber, pure Tb target with a sputtering power of 30 W and the substrate temperature was set at 350 °C. Following deposition, the thin film underwent annealing at 1200 °C for 1 hour.The TEM samples prepared by mechanical method and annealed at 1200 ⁰C, Fig. 1(a), showed a well-defined crystal structure. The dark points on the sample represent the nanocrystals of terbium disilicate. The average thickness of the sample is approximately 168.88 nm. Fig. 1(b) displays the ORSO:Tb annealed at 1200 ⁰C, showing the cross-sectional morphology of well-ordered nanostructures on the specimen with Tb doping, prepared by FIB. The cross-section of the thin film is well-ordered, and the FIB process did not disrupt the crystal structure of the sample annealed at high temperature, nor did it lead to the formation of a new structure. Furthermore, a comparative analysis between the TEM-prepared sample employing the mechanical method and the one prepared using FIB makes it evident that the FIB-prepared sample possesses superior resolution. The size distribution of particles is approximately the same, while due to the higher resolution of the TEM sample prepared through FIB, exhibits a particle distribution with a greater range with more details. In contrast, particle size determination in the mechanical method is more challenging due to its lower resolution, determining details and size characterization more difficult. Conclusion The ORSO:Tb sample was fabricated using the IMS ECR-PECVD system at 1200 degrees. Based on the findings presented in the paper, the effect of FIB, particularly at high annealing temperatures, does not induce significant damage to the crystal structure of ORSO:Tb thin film. The particle size distribution in the TEM sample prepared with FIB is broader and more detailed than in the mechanical due to its higher resolution. Particle size determination using the mechanical method is more challenging due to its lower resolution, making it more difficult to distinguish details and characterize sizes. Additionally, atomic composition analysis indicated the accurate abundance of oxygen in oxygen-rich silicon oxide. Figure 1

Minimizing surface adhesion of Sylgard 184 for medical applications

Silicones such Sylgard 184 are widely employed in biological applications due to their versatile properties. However, their inherently adhesive surfaces can restrict their application, especially in direct contact with damaged biological tissues, potentially compromising patient comfort. To enhance the surface properties of Sylgard 184 while maintaining its transparency in the visible spectrum, a novel low-temperature method (70 °C) has been developed. This method involves immersing PDMS in a solution of titanium (IV) ethoxide in THF, thus inducing swelling of the silicone's polymer network, followed by the diffusion and condensation of titanium (IV) ethoxide within the polymer matrix. The resulting hybrid material, incorporating amorphous titanium oxide within the silicone network, exhibits significantly increased surface hardness compared to unmodified Sylgard 184, while retaining transparency and improving biological behaviour. The elaborated method holds promising potential for enhancing the performance of silicone-based materials in diverse biomedical applications.

Research progress on pretreatment technology for the analysis of amphetamine biological samples.

Sample pretreatment technology is crucial for drug analysis and detection, because the effect of sample pretreatment directly determinates the final analysis results. In recent years, with the continuous innovation of microextraction and other technologies like material preparation technologies and assistant technologies for extraction, the sample pretreatment techniques in the process of drug analysis have become more and more mature and diverse. This article takes amphetamine (AM) or methamphetamine as an example to review the recent development of pretreatment methods for AM-containing biological samples from the perspectives of extraction techniques, extraction media and auxiliary technologies. Extraction techniques are summarized with the categories of contact microextraction, separate microextraction and membrane-based microextraction for better guidance of application according to their features. Prevailing and innovative extraction media including carbon-based material, silicon-based material, metal organic framework, molecularly selective materials, supramolecular solvents and ionic liquids are reviewed. Auxiliary technologies like magnetic field, electric field, microwave, ultrasound and so on which can enhance extraction efficiency and accuracy are also reviewed. In the last, prospects of the future development of pretreatment technology for the analysis of AM biological samples are provided.