Interlayer Gap Research Articles

Effects of Intercalation on ML-Ti3C2Tz MXene Properties and Friction Performance.

Intercalation in two-dimensional (2D) materials can modify their physical, chemical, and electronic properties. This modification enables the tailoring of 2D material characteristics, enhancing their performance and expanding their applications in various fields. The friction performance of 2D materials such as MoS2 and graphite has a strong dependence on their interlayer spacing, and they exhibit an increase in d-spacing associated with a reduction in friction performance. The ability to control the interlayer spacing of Ti3C2Tz MXene has proven beneficial for energy storage applications such as batteries and supercapacitors, but no one has utilized this control of interlayer spacing for lubrication. In this study, we demonstrate that interlayer spacing of multilayer (ML) Ti3C2Tz MXene can be controlled through chemical intercalation and its direct effects on the electrical conductivity and friction performance. We observed a notable decrease in electrical conductivity in vacuum-filtered ML-Ti3C2Tz MXene films, which was attributed to an increased internal resistance resulting from the expansion of the interlayer gap. We also found a significant reduction in the coefficient of friction for ML-Ti3C2Tz MXene with an increased d-spacing. This reduction is attributed to a weakened attraction of individual ML-Ti3C2Tz MXene layers (intercalated). Under a tangential force, it becomes easier to slide within the larger interlayer gap with weakened van der Waals forces. This work provides insights into the tunability of MXene properties through interlayer spacing, offering potential applications requiring materials with specific electrical and friction characteristics.

Effect of hydration process on the interlayer bond tensile mechanical properties of ultra-high performance concrete for 3D printing

It is crucial to reveal interlayer interface characteristics for fully analysing the mechanical properties of 3D printed ultra-high performance concrete (3DP-UHPC). Despite its significance, the interlayer bonding behaviour of 3DP-UHPC has not been fully explored. To fill this gap, this study adopted different curing times and conditions to investigate the effect of hydration process on the interlayer microstructure and mechanical properties under different interlayer interval times. As the result show that, the interlayer microstructure remained dense for interval times less than 5 minutes, but interlayer gaps became increasingly apparent as the interval time exceeded this threshold. Promoting hydration, however, helped heal interlayer defects in 3DP-UHPC. Additionally, the interlayer bond tensile strength gradually decreased with increasing interval time but remained almost unchanged when the interval time exceeded 1 day. Notably, hot water bath curing enhanced the bond tensile strength of specimens with interval times within 60 minutes, but its improvement was insignificant for interval times exceeding 1 day. Based on these experimental results, a preliminary interlayer bond tensile stress-strain equation of 3DP-UHPC was derived. The findings of this study offer promising avenues for the improvement and promotion of 3DP-UHPC technology.

Inverse design of ultra-compact high-efficiency broadband interlayer couplers based on random gratings

Ultra-compact high-efficiency broadband interlayer couplers based on random gratings are inversely designed by particle swarm optimization algorithm. The optimal structure is obtained by adjusting the pixel state to achieve a maximum coupling efficiency in 1550 nm band. The two-layer coupler consists of two vertically overlapping inverse taper waveguides with random gratings. With a short coupling length of 4 μm and interlayer gap of 200 nm, the coupling efficiency reaches 93% at a wavelength of 1550 nm, and exceeds 90% over a broadband wavelength range of 1503∼1600 nm, for both TE and TM mode. The coupling efficiency can maintain no less than 90% at a large waveguide misalignment of >100 nm, exhibiting high process error tolerance. The performance of the 4 μm-long inverse-designed coupler is higher than the conventional waveguide with a much large length of 10 μm. To achieve longer transmission distance, a tri-layer interlayer coupler is proposed by cascading two bi-layer couplers, which exhibits a remarkable coupling efficiency of 85% at a gap of 600 nm, more than 30 times higher than the bi-layer structure. This work may pave the way for the development of ultra-compact high-performance interlayer couplers supporting high-integration Si-based photonic integrated circuits.

Improving mechanical and electrical contact performance of silver based electrical contact material reinforced by flower spherical zinc oxide loaded with silver nanoparticles

Flower spherical ZnO loaded with Ag nanoparticles was synthesized by hydrothermal method. Ag/ZnO electrical contact materials were prepared by powder metallurgy combined with hot extrusion technique. During the hydrothermal reaction, Ag nanoparticles entered the interlayer gaps of flower spherical ZnO and uniformly deposited on its surface. The tensile mechanical test results indicate that the Ag/ZnO electrical contact materials prepared by ZnO, Ag@ZnO(75 wt%) and Ag@ZnO(50 wt%) exhibited elongations of 6.8 %, 13.8 % and 12.1 %, respectively. This result indicates that appropriate loading of Ag nanoparticles on flower spherical ZnO could significantly improve the mechanical properties of Ag/ZnO electrical contact materials. The contact resistance of electrical contact materials significantly affects their temperature rise characteristics. During 20, 000 cycles process, Ag/ZnO electrical contact material prepared by Ag@ZnO(50 wt%) exhibited the lowest temperature rise of 6.33 K under the conditions of DC 36 V/10 A. Considering both mechanical and electrical contact performance, Ag/ZnO electrical contact materials prepared by Ag@ZnO(50 wt%) exhibited the optimum overall performance.

Pressure-Induced Molding of Black Phosphorus@Ti3C2Tx Composite Electrode and Its Implications on the Lithium Storage.

For the first time, an innovative pressure quenching technique is used to create the integrated electrode of the black phosphorus (BP) @Ti3C2Tx composite material, doing away with the requirement for adhesive additives and simplifying time-consuming processes. Through the formation of Ti-O-P bonds with BP, Ti3C2Tx MXenes can function as conductive additives and affect the interlayer gap. Additionally, we have found that there is a critical synthetic pressure threshold (300 kN) at which the performance of BP@Ti3C2Tx-integrated electrodes can be improved: too high of a pressure prevents lithium-ion transport because of mesopore reduction; too low of a pressure prevents Ti-O-P chemical bond formation between the two components; and suboptimal pressure does not allow for density enhancement for better electron conduction. The integrated electrode produced at 300 kN shows a discharge capacity of about 724.9 mA h/g at 0.1 A/g current density after 100 cycles, which is much larger than that obtained at 50 kN (270.2 mA h/g). Furthermore, the capacity can remain steady at 560.74 mA h/g even after 500 lengthy cycles at the high current density of 0.5 A/g. Significantly lower resistance (1.10 × 102 Ω at 300 kN; 2.02 × 103 Ω at 50 kN) and faster reaction kinetics are responsible for this improvement. This study offers a new, straightforward, and broadly useful technique for creating integrated electrodes and BP-based composite materials.

Detection of ballastless track interlayer gap based on vehicle’s multivariate dynamic response and deep learning

To adapt to the rapid detection of interlayer damage in ballastless track structures of high-speed railways, a cement asphalt mortar (CAM) gap localization and damage degree classification scheme based on multivariate data fusion and deep learning is proposed. Based on vertical axle box acceleration (VABA) and vertical wheel-rail force (VWRF) data, the variation patterns of multi-dynamic response data of vehicles under the edge type and internal type interlayer gaps are analyzed. An improved ensemble local mean decomposition algorithm (IELMD) is designed to achieve data denoising and preliminary enhancement preprocessing of weak damage features for VABA and VWRF under interlayer gaps. The measured and simulated VABA and VWRF constituted multiple dynamic response data sets for interlayer gap detection. An interlayer gap detection model: DTA-Tcnformer is constructed, integrating a dual temporal convolutional network with an attention mechanism, transformer architecture, and gate control mechanism. Multiple dynamic response data are input into the model to locate and classify 24 cases of the two interlayer gap types. The influence of damage cases and vehicle speeds on the location effect is analyzed. The learning ability of the proposed model on the gap features is visualized. The misidentification and omission of the gap cases are calculated, and the comprehensive recognition accuracy is 92.48 %. The recognition performance of the proposed model is compared and verified.

A Functionalized Scaffold Facilitates Neurites Extension for Spinal Cord Injury Therapy.

Scaffolds have garnered considerable attention for enhancing neural repairment for spinal cord injury (SCI) treatment. Both microstructural features and biochemical modifications play pivotal roles in influencing the interaction of cells with the scaffold, thereby affecting tissue regeneration. Here, a scaffold is designed with spiral structure and gradient peptide modification (GS) specifically for SCI treatment. The spiral structure provides crucial support and space, while the gradient peptide isoleucine-lysine-valine-alanine-valine (IKVAV)modification imparts directional guidance for neuronal and axonal extension. GS scaffold shows a significant nerve extension induction effect through its interlayer gap and gradient peptide density to dorsal root ganglia in vitro, while in vivo studies reveal its substantial promotion for functional recovery and neural repair. Additionally, the GS scaffold displays impressive drug-loading capacity, mesenchymal stem cell-derived exosomes can be efficiently loaded into the GS scaffold and delivered to the injury site, thereby synergistically promoting SCI repair. Overall, the GS scaffold can serve as a versatile platform and present a promising multifunctional approach for SCI treatment.

Optimized preparation of La3Mn2O7 with superior lattice oxygen mobility and adsorbed oxygen utilization for catalytic removal of toluene

The R-P type layered perovskite La3Mn2O7 (LLM) is considered a more promising toluene oxidation catalyst than perovskite LaMnO3 (LMO) due to the versatile environment it provides for oxygen atoms, yet the challenge of realizing an optimal synthesis route remains. Herein, we revealed how calcination temperature influenced the structure–activity relationship and the mechanism by which the layered structure enhanced oxygen species reactivity. LLM700 possesses optimal toluene adsorption performance, oxygen species activation capability and low-temperature reducibility, thus exhibiting the highest catalytic activity (T90 = 283 °C) among single layered perovskite catalysts. The large interlayer gaps in the layered structure, combined with the weaker Mn-O bond strength near the layered structure, facilitate the easy removal of oxygen atoms, creating oxygen vacancies that act as pathways for oxygen ions to migrate within the lattice. Together, these factors enable the layered structure to enhance the mobility of lattice oxygen and the utilization of adsorbed oxygen, making LLM an ideal model for catalyzing the oxidation of toluene. Furthermore, the possible reaction pathway for the oxidation of toluene on LLM700 was inferred using GC–MS. This work paves the way for the catalytic applications of layered perovskites.

Damage characteristics and mechanical properties of CRTS III track structure in curved sections under longitudinal uneven subgrade settlement

This paper first presents a CRTS III track structure (TS) model specifically designed for curved sections, highlighting its adjustable superelevations feature that enhances adaptability to various high-speed railway curve profiles. The model considers the distribution of steel bars within the TS, concrete damaged plasticity, as well as contact nonlinearity. Afterward, the intricate impacts of longitudinal uneven subgrade settlement (LUSS) position (7 positions), amplitude (5–30 mm), wavelength (5–30 m), and TS superelevation (15–175 mm) on structural damage, stress, deformation, and interlayer gap are studied. The findings reveal that: 1) Under different LUSS positions, the concrete base (CB) experiences the most severe damage, particularly on its thick side. For the TS with 175 mm superelevation, in the wavelength range of 10–20 m, the maximum damage value of CB exceeds 0.9 when LUSS amplitude reaches 20 mm. With the movement of LUSS position, the main damage position of CB changes obviously. When the concrete stress reaches the tensile strength, the steel bars located in adjacent positions progressively assume the primary role in load-bearing. 2) The influence of LUSS on TS deformation and interlayer gap is inevitably associated with the distance between settlement center and expansion joints. Interlayer gaps vary among structural components, which are primarily distributed near settlement center, expansion joints, and settlement edges. 3) As the amplitude increases, both CB and self-compacting concrete layer (SCCL) damage are aggravated. Increasing wavelength initially causes damage to increase, then decrease, and 10–20 m is the most unfavorable wavelength range for most cases. 4) The effect of superelevation on TS damage is complex, varying with structural components and settlement characteristics. In most cases, as superelevation increases, the damage to CB increases, whereas the deformation decreases.

Influence of printing parameters on the thermal properties of 3D-printed construction structures

3D printing in the construction sector is a promising, sustainable approach with the potential to build energy-efficient buildings. However, there is a lack of studies on the thermal properties of 3D-printed structures, which are fundamental to their energy efficiency. This study investigates the impact of printing parameters on thermal conductivity and defect development in 3D-printed concrete structures. Heat flow meter, scanning electron microscope and infrared imaging techniques were employed to assess the thermal properties and microstructure of 3D-printed samples. The results demonstrate that printing parameters significantly influence the porosity, void formation, and microstructural characteristics of 3D-printed concrete, ultimately affecting thermal properties. An increase in extrusion rate leads to higher thermal conductivity, whereas an increase in speed and standoff distance reduces thermal conductivity. Excessive spacing between printed lines can induce voids and gaps, contributing to lower thermal conductivity, while minimal spacing can promote higher porosity and larger pores. Infrared imaging revealed nonuniform thermal distribution in 3D-printed structures caused by the layered structure and voids in interlayer gaps. This study provides valuable insights for designing and constructing energy-efficient 3D-printed buildings, contributing to the development of sustainable building practices and the advancement of additive manufacturing in construction.

One-step and universal fabrication of MXene/metal sodiophilic frameworks via Lewis acidic etching toward dendrite-free sodium metal anodes

Although MXene-based 3D scaffolds have boosted the cyclability of Na metal, the complex and harsh synthetic process deteriorates their practical application. Herein, a series of MXene/metal sodiophilic frameworks are constructed through one-step Lewis acidic etching, and metal nanoparticles are uniformly distributed on the surface or intercalated into the large interlayer gaps of MXenes. Notably, MXenes with superior Na+/electron transport kinetics and mechanical flexibility remarkably reduce the local current density, homogenize Na+ flux and cushion huge volume change of Na metal. Moreover, sodiophilic species including MXenes and metals effectively induce Na uniform nucleation and smooth deposition among the 3D matrixes, leading to dendrite-free morphology. Consequently, MXene/metal hosts exhibit stable Na plating/stripping process for 900 cycles with high average Coulombic efficiencies of 99.9% (2 mA cm−2, 1 mAh cm−2). The MXene/metal-Na symmetric cells achieve low overpotentials of less than 15 mV and stable cycling for 2200 h (2 mA cm−2, 4 mAh cm−2). When paired with Na3V2(PO4)3 cathode, the full cells with a low N/P ratio (around 2) demonstrate high discharge capacity and excellent long-term cyclic performance over 600 cycles. The presented universal, safe and one-step approach in fabricating MXene/metal scaffolds shows bright prospects and may promote the development of alkali metal-based batteries.

Effect of interlayer thickness and gap distance on vaporizing foil actuator welding of 5A06 aluminium alloy and 321 stainless steel

The composite structure of aluminium alloy and stainless steel provides a wide range of comprehensive advantages, encompassing properties such as lightweight, high strength, and corrosion resistance. These advantages make composite structure particularly suitable for various applications in industries such as transportation and chemicals. One innovative solid-phase welding technology that is well suited for joining dissimilar materials is vaporizing foil actuator welding. This technology allows for the welding of composite structures made of aluminium and stainless steel, despite the significant differences in physical and chemical properties. To enhance the vaporizing welding process, this paper proposes the introduction of an interlayer between the dissimilar materials. The interlayer consists of a third material that is added to bridge the gap between materials with differing hardness and plasticity. The main objective of introducing the interlayer is to minimise performance disparities and reduce the formation of intermetallic compounds at the interface. By examining the vaporizing foil actuator welding process of aluminium alloy and stainless steel with the interlayer, it aims to analyse the characteristics of the interface morphology. Additionally, this study investigates the energy conversion mechanism of the aluminium foil gasification process and explore the influence of the interlayer on the microstructure and mechanical properties of the interface between aluminium alloy and stainless-steel joints.

Strategy for developing aluminum alloy-based solid structure with homogeneous properties in the overlapping direction using wire arc additive manufacturing

This research investigates the strategy for developing large-scale solid aluminum structures with multi-bead multi-layer (MBML) overlapping using wire-arc additive manufacturing (WAAM). The study addresses challenges, i.e. material accumulation, surface irregularities, and inter-bead and inter-layer gaps, by examining deposits’ geometrical characteristics, process parameters, and deposition methods. Initial test coupon solid blocks are printed and analyzed using optical microscopy, and subsequent statistical optimization leads to the successful printing of a defect-free 140 mm × 150 mm × 28 mm solid block. The flat surface achieved in the MBML structure is attributed to maintaining an optimal overlap coefficient and a parabolic profile with the maximum width at the base. Microstructural analysis reveals the absence of fusion gaps, with an average porosity of 11.7 ± 2.45%, due to hydrogen evolution and reheating effects, with few larger pores near fusion lines. The microstructural and mechanical analyses confirm the homogeneity of properties along the overlapping direction (OD), with microhardness averaging 85.80 ± 6.63 HV0.1 and tensile strength of 161.55 ± 1.19 MPa with 2.18 ± 0.08% elongation. Microhardness fluctuations along the OD are attributed to fusion boundaries, partially melted and heat-affected zones. The research revealed that careful consideration of bead geometry and process parameters is crucial for achieving defect-free aluminum solid structures in WAAM through MBML overlapping.

Alumina Ceramics for Armor Protection via 3D Printing Using Different Monomers.

Alumina ceramic is an ideal candidate for armor protection, but it is limited by the difficult molding or machining process. Three-dimensional printing imparts a superior geometric flexibility and shows good potential in the preparation of ceramics for armor protection. In this work, alumina ceramics were manufactured via 3D printing, and the effects of different monomers on the photosensitive slurry and sintered ceramics were investigated. The photosensitive slurries using dipropylene glycol diacrylate (DPGDA) as a monomer displayed the optimal curing performance, with a low viscosity, small volume shrinkage and low critical exposure energy, and each of the above properties was conducive to a good curing performance in 3D printing, making it a suitable formula for 3D-printed ceramic materials. In the 3D-printed ceramics with DPGDA as a monomer, a dense and uniform microstructure was exhibited after sintering. In comparison, the sample with trimethylolpropane triacrylate (TMPTA) showed an anisotropic microstructure with interlayer gaps and a porosity of about 9.8%. Attributed to the dense uniform microstructure, the sample with DPGDA exhibited superior properties, including a relative density of 97.5 ± 0.5%, a Vickers hardness of 19.4 ± 0.8 GPa, a fracture toughness of 2.6 ± 0.27 MPa·m1/2, a bending strength of 690 ± 54 MPa, and a dynamic strength of 3.7 ± 0.6 GPa at a strain rate of 1200 s-1.

Flame retardancy and smoke suppression effect of zinc borate-graphite intercalation compound/Fe2O3 on silicone rubber foams

To enhance the flame retardancy and smoke suppression of silicone rubber foams (SRFs), a novel flame retardant, zinc borate-graphite intercalation compound (ZB-GIC), was synthesized and used in conjunction with Fe2O3. The results showed that ZB-GIC markedly improved the flame retardancy and smoke suppression of SRFs, and Fe2O3 significantly improved the smoke suppression of SRFs. ZB-GIC and Fe2O3 had an excellent synergistic effect on flame retardant and smoke suppression. 5 wt% ZB-GIC synergistically with 5 wt% Fe2O3 resulted in SRFs passing the UL-94 V-0 rating, whose limiting oxygen index (LOI) value reached up to 43.7%. Its peak heat release rate (PHRR), total heat release (THR), peak smoke production rate (PSPR), and total smoke production (TSP) decreased by 67.42%, 89.55%, 76.86%, and 91.67% compared to pure SRF. The ZB-GIC produced incombustible gas and a large amount of H2O when heated, which reduced the intensity of gas-phase combustion. The ZB filled the interlayer gaps formed after the expansion of GIC to enhance the strength of the char layer, and Fe2O3 further strengthened the char layer. Our work has greatly reduced the fire hazards of SRFs and provided a promising flame retardant for the large-scale production of high-performance SRFs.

Inter-layer structures regulated by metallic Si powders in 3D printing of silica-based ceramic cores

3D printing is an excellent choice for manufacture of ceramic cores; however, the inter-layer structures in 3D printed sample leads to anisotropy in microstructure and properties. In this paper, silica-based ceramic cores were prepared by digital light processing, and metallic Si powder was employed as mineralizer to relieve the anisotropy. The metallic Si powder converts into SiO2 in oxidation reaction with significant volume expansion, which inhibits the shrinkage rate and partly fills the interlayer gaps of the ceramic core. Meanwhile, the metal Si powder leads to lower curing thickness in 3D printing, and thicken the interlayer gaps. Due to the cooperation of the oxidation reaction and decreased curing thickness by the metallic Si powder, the 0.4 wt% of metallic Si powder reduced the anisotropy in structure and mechanical property due to the alleviated inter-layer structure and the interlayer and intralayer strengths show optimal values of 11.4 MPa and 17.2 MPa at room temperature, respectively. This work inspires new guidance to 3D printing of ceramic cores with uniform microstructure and excellent mechanical properties.

Experimental study on the influencing factors of coalescer and liquid film interception theory

Coalescer are commonly utilized in the realm of deep gas drying field, and its performance is contingent upon the filter. The filter consists of a support structure, a coalescing layer, and a drainage layer. However, research focuses more on the impact of coalescing and drainage layers on coalescence performance. The impact of the support structure and the interlayer gap of the coalescing layer on coalescence performance during the production process remains unknown. To address the issue, the experiments were performed under 0.30 m/s surface velocity and 2.50 g/min liquid loading rate with coalescing layer ranging from 1 to 6 layers. Variation of pressure drop under different supports identified a statistically significant advantage for diamond mesh over orifice. The three placement methods' specific order of pressure drop is both-sided > front-side> no-support > back-side placement. Based on experimental evidence showing that liquid film interception of droplets dominates in the coalescence process, the liquid film interception theory was proposed. Further, based on the "liquid film interception theory", the effect of interlayer gaps on coalescence performance was researched. The results show that setting interlayer gaps corresponds to an increase in separation efficiency by 1–4 %, an increase in wet pressure drop by 34.63–63.86 %, and a decrease in quality factor by 208.76 %. Therefore, to achieve high-performance filter media, interlayer gaps should be avoided during the manufacturing process.

Intelligent Method for Corrosion Detection and Quantification in Aircraft Lap Joints Using Pulsed Eddy Current

Nondestructive evaluation using pulsed eddy current (PEC) has remarkable capabilities for the detection and characterization of hidden corrosion in multilayer structures. Previous works proposed maximum peak value, time-to-peak, and time-to-zero crossing of PEC signals for hidden corrosion detection. In practice, there are two important noise sources: probe liftoff and interlayer gap. These noise sources disable the aforementioned components in defect detection and classification. This paper delivers a new intelligent method for detection and classification of corrosion defects in two-layer structures at the presence of gap and liftoff. Application independent component analysis and principal component analysis to PEC signals for features extraction and Fisher’s linear discriminant method for classification provide an automatic material loss characterization in multilayer structures. Comparing the results with conventional methods based on PEC signals shows the importance of post-processing methods in the detection and quantification of corrosion.

Numerical and theoretical approach to evaluate the clamping force and the interlayer gap extent during drilling of stacked materials

In the aeronautical industry, one-shot drilling of stacked materials is a widely adopted and established solution. However, ongoing discussions persist, particularly regarding the issue of interlayer gap formation that arises when two or more unsealed materials are drilled together. This study aims to present a simplified and reproducible theoretical model based on the equation of the elastic curve applied to structural schemes that discretize and describe the interlayer gap phenomenon in the drilling process. The model is designed to estimate the extent of the interlayer gap phenomenon and predict the clamping force required for its reduction when an end-effector is employed as a clamping device during the drilling of stacked sheets. Experimental and finite element analyses were conducted to validate the results of the proposed theoretical model. Each model was developed and applied to a real structural unit of a fuselage panel, considering actual boundary conditions in terms of structural constraints and geometric features of the assembly. The results obtained in this study demonstrate that the proposed one-dimensional theoretical model consistently aligns with experimental and numerical observations obtained through finite element analysis. This offers an effective and readily implementable solution in an industrial context as a tool for sizing the clamping force exerted by a clamping device.

Fibrillation of Pristine 2D Materials by 2D‐Confined Electrolytes

Abstract2D materials are solid microscopic flakes with a‐few‐Angstrom thickness possessing some of the largest surface‐to‐volume ratios known. Altering their conformation state from a flat flake to a scroll or fiber offers a synergistic association of properties arising from 2D and 1D nanomaterials. However, a combination of the long‐range electrostatic and short‐range solvation forces produces an interlayer repulsion that has to be overcome, making scrolling 2D materials without disrupting the pristine structure a challenging task. Herein, a facile method is presented to alter the 2D materials’ inter‐layer interactions by confining organic salts onto their basal area, forming 2D‐confined electrolytes. The confined electrolytes produce local charge inhomogeneities, which can conjugate across the interlayer gap, binding the two surfaces. This allows the 2D‐confined electrolytes to behave as polyelectrolytes within a higher dimensional order (2D → 1D) and form robust nanofibers with distinct electronic properties. The method is not material‐specific and the resulting fibers are tightly bound even though the crystal structure of the basal plane remains unaltered.