Quartz Fiber Research Articles

Particle and gas phase sampling of PCDD/Fs and dl-PCBs by activated carbon fiber and GC/MS analysis

Polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), and polychlorobiphenyls (PCBs) are semi-volatile compounds and can be partitioned in the atmosphere between the gas and particulate phase, due to their physicochemical properties. For this reason, the reference standard methods for air sampling include a quartz fiber filter (QFF) for the particulate and a polyurethane foam (PUF) cartridge for the vapor phase, and it is the classical and most popular sampling method in the air. Despite the presence of the two adsorbing media, this method cannot be used for the study of the gas-particulate distribution, but only for a total quantification. This study presents the results and the performance aim to validate an activated carbon fiber (ACF) filter for the sampling of PCDD/Fs and dioxin-like PCBs (dl-PCBs) using laboratory and field tests. The specificity, precision, and accuracy of the ACF in relation to the QFF + PUF were evaluated through the isotopic dilution technique, the recovery rates, and the standard deviations. Then the ACF performance was assessed on real samples, in a naturally contaminated area, through parallel sampling with the reference method (QFF + PUF). The QA/QC was defined according to the standard methods ISO 16000–13 and -14 and EPA TO4A and 9A. Data confirmed that ACF meets the requirements for the quantification of native POPs compounds in atmospheric and indoor samples. In addition, ACF provided accuracy and precision comparable to those offered by standard reference methods using QFF + PUF, but with significant savings in terms of time and costs.

High-temperature heat transfer simulation and optimization of quartz fiber-aerogel composite multilayer 3D fabric

Quartz fabrics, which have excellent mechanical properties and high temperature resistance abilities, had been widely applicated in aerospace, military, and other thermal insulation fields. However, single-layer quartz fabric has poor thermal insulation performance, which is unfavorable to the high temperature application of this material. In order to improve the thermal insulation effect of quartz fiber fabric, silica aerogel materials with outstanding thermal insulation performance were introduced to the fabrication of quartz fabrics. Thermal insulation properties of quartz fiber and mechanical properties of silica aerogel were improved by a 3D braiding technique. Firstly, a 3D-fabric structure of quartz fiber-aerogel multilayer composite was designed. Silica aerogel and quartz yarn were woven into 3D composite fabric by textile technique. Through 3D braiding technique, silica aerogels were protected by quartz yarns while enhancing their mechanical properties. The thermal insulation performance and high temperature erosion resistance of the fiber-aerogel fabric are improved. Secondly, to explore the influence of the internal structure of the 3D fiber-aerogel composite fabric, a full-scale 3D simulation model for the heat transfer performance of fiber-aerogel multilayer composite was established. The thermal insulation performance of the composite fabric at 700 °C was predicted. Finally, the temperature of different positions inside the fabric in different environments (300 °C, 400 °C, 500 °C, 600 °C, 700 °C) was tested. It has been proved that introducing aerogel materials to the quartz fabric could reduce the surface temperature by about 60%.

A Prediction Method of Effective Modulus of POSS Modified Quartz Fiber Reinforced Silicone Matrix Unidirectional Composites

In the manufacturing process of Polyhedral oligosilsesquioxane(POSS) modified quartz fiber reinforced silicone resin composite, if the POSS content ratio and the combination performance of POSS and silicone resin can be effectively controlled, the comprehensive performance of the material can be significantly improved, and many weaknesses of the composite can be improved. At the same time, the substantial problems such as the stiffness and strength of the wave transmitting composite still need to be greatly improved can be solved, and the new wave transmitting composite can be widely used in the main bearing parts of aerospace. When POSS modified quartz fiber reinforced silicone resin matrix composites are used as structural materials, their mechanical properties, such as modulus, are one of the most important macro mechanical material parameters in engineering applications. However, there is no effective prediction method in engineering to give practical guidance. Therefore, this paper establishes a prediction method of effective modulus of POSS modified quartz fiber reinforced silicone resin matrix composites based on micromechanics, The system can accurately understand the relationship between material structure and properties, thus making it possible to predict properties and design materials, and quickly guiding the practical application of engineering.

Development of Heat-Resistant Composite Foam Material

The paper is devoted to the research results dealing with the development of heat-resistant composite cellularmaterial, where polymer matrix is based on10% polycarbosilanesolution in xylene, hollow microspheres and fibrous mineral material are used as fillers. In this study, the used hollow microspheres are corundum and aluminosilicate microspheres, and fibrous filler is quartz fiber. According to the experiments, the best results refer to thecomposite foam samples, containing hollow corundum microspheres as filler. The developed composite foam is characterized with low thermal conductivity and density, good physical and mechanical properties,when polymer binder content was 20-70% wt., corundum hollow microspheres - 20-60% wt., and quartz fiber material - 10-50% wt. Thus, the developed composite foam might be recommended for the applicationin high-tech industries, including heat and power engineering, nuclear power and aircraft construction as high-temperature thermal insulation material.

QUARTZ FIBER RADOME AND SUBSTRATE FOR AEROSPACE APPLICATIONS

This study investigated the use of quartz fiber as an antenna radome and a dielectric substrate for a patch antenna designed to operate at f=8 GHz. To compare the performance of quartz fiber as an antenna radome, glass fiber is examined for the same antenna. For the substrate case, quartz fiber is compared with the well-known and widely used dielectric substrate, FR-4. The electromagnetic properties of the quartz fiber were examined for different temperature values using a free space measurement setup and a controllable furnace. The complex electrical permittivity (ε) values of glass and quartz fiber are measured using a free-space setup. The antenna parameters, including radiation pattern, gain, return loss, and beamwidth, are investigated and compared in detail for all cases to demonstrate the effects of the use of quartz fiber as a radome and an antenna substrate

Crucible Effect on Phase Transition Temperature during Microwave Calcination of a N-Doped TiO2 Precursor: Implications for the Preparation of TiO2 Nanophotocatalysts

Nitrogen-doped titanium dioxide (N–TiO2) is extensively studied in the literature and widely employed as a visible-light photocatalyst. The preparation of this nanomaterial often involves a final calcination step: in this paper, we used microwave technology as an efficient and environmentally friendly tool for the calcination of a mixed anatase/brookite phase precursor containing organic compounds arising from its synthesis. A wide study was performed, comparing results obtained in quartz fiber-made crucibles, porcelain crucibles, microwave (MW) and conventional heating, and also using a pristine TiO2 as a reference material. Weight percentages of the three main TiO2 polymorphs obtained in different calcination conditions were determined by X-ray powder diffraction (XRPD) data and Rietveld refinements, and the results are discussed. We found that the calcination’s outcome is dramatically affected by the crucible used: while mixed-phase nanomaterials were obtained when using classic porcelain crucibles, only the rutile phase was obtained when working in a quartz fiber crucible at temperatures as low as 250 °C. The direct material’s temperature measurement inside the microwave oven showed that this finding is not due to a microwave effect but to a thermal effect caused by the particular crucible employed that favors better combustion of organics and prompts rutile formation. Nitrogen doping of this material was inferred by ultraviolet–visible–diffuse reflectance spectroscopy (UV–vis–DRS).

Spatiotemporal variability and measurement uncertainty in atmospheric polycyclic aromatic hydrocarbons (PAHs): A quantitative variance component analysis

A comprehensive understanding of the spatial and temporal variability in air pollution facilitates air monitoring designs, exposure assessment, and environmental epidemiology research. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the air but are challenging to measure due to their low concentrations. To date, no study has been specifically designed to quantify the spatial and temporal aspects of variability in ambient PAH concentrations. This study aims to decompose the variability in PAH concentrations measured in the ambient air in a metropolitan area into different components. Air samples were collected using high-volume samplers at 19 stations in the Memphis Tri-state Area across Tennessee, Arkansas, and Mississippi, USA, every 12 days from March 2018 to May 2019. Samples were collected on polyurethane forms and quartz fiber filters and analyzed using gas chromatography/mass spectrometry (GC/MS) for 32 PAHs. Variance components of the total variance were computed using mixed models for individual PAHs and sum concentrations of the 16 priority PAHs (Σ16PAHs). For Σ16PAHs, spatial and temporal variability represented 16% and 84% of the total variance. The total variance could be further apportioned to between-urbanicity (0.5%), between-site (5.5%), between-season (41%), and within-season (53%) variances. Sampling and analytical uncertainties represented 39% and 0.01% of the total variance, when monitoring uncertainties were considered. Concentrations of individual PAHs followed similar variance structures. These findings confirmed the validity of centralized monitoring stations to represent a large area, suggested the need for repeated samples across seasons and at multiple time points within a season, and warranted improving quality control for field sample collections.

Characterization, risk assessment, and source estimation of PM10-bound polycyclic aromatic hydrocarbons during wintertime in the ambient air of Basrah City, Iraq

In this study, the concentration and structure of polycyclic aromatic hydrocarbons (PAHs) associated with the ambient PM10 in Basrah City, Iraq have been investigated for the first time. From December 2021 to February 2022, PM10 samples were collected on quartz fiber filters, extracted using an optimized extraction protocol, and analyzed for the sixteen US EPA priority PAHs. The results indicated that 4- and 5-ring PAHs represent 52% of the total detected PAHs. The most abundant PAHs over the study period were chrysene (1.2 ± 1.5 ng m−3), fluorene (0.9 ± 1.4 ng m−3), and benzo[b]fluoranthene (0.7 ± 0.9 ng m−3). Source identification suggested that PM10-bound PAHs primarily originated from pyrogenic and petrogenic activities in Basrah City. In addition, the cancer risk associated to PAH exposure was assessed based on benzo[a]pyrene equivalent concentration and was found ranging from 0.07 to 6.32 ng m-3; hence, it exceeded the threshold limit of 1.0 ng m−3 established by the European legislation (EU, 2014). Benzo[a]pyrene was determined to be main contributor to total carcinogenic power of the detected PAHs, accounting for 50.3%, followed by dibenz[a,h]anthracene (22.3%). Similarly, benzo[a]pyrene represented a major contributor to PAH associated mutagenicity, accounting for 43.5% of the total.

Evaluation of 213-nm laser as an affordable alternative for the green elemental characterization of particulate matter on quartz fibre filters by laser ablation ICPMS

Evaluation of 213-nm laser as an affordable alternative for the green elemental characterization of particulate matter on quartz fibre filters by laser ablation ICPMS

Experimental investigation on mechanical behaviors of composite sandwich panels with a hybrid facesheet

AbstractA multi‐functional composite sandwich panel was developed with a hybrid facesheet, which was composed of a quartz fiber reinforced plastic (QFRP) laminate and two copper layers. The other facesheet was made of QFRP laminate. The Nomex® honeycomb was used as the core material. The aim of this paper is to investigate the effects of the hybrid facesheet on the mechanical characterizations of the sandwich panel. Four mechanical performances of both composite sandwich panel with and without copper layers were considered, including the flatwise tensile strength test, the edgewise compressive strength test, the three‐point bending test and the tensile plate shear test. The experimental results show that all the four mechanical performances of the sandwich panel with copper layers were lower than the sandwich panel without copper layers. The flatwise tensile strength decreased by 26.1%. The edgewise compressive strength decreased by 9.5%. The shear strength obtained from the three‐point bending test decreased by 14.9%. The shear strength obtained from tensile plate shear test decreased by 13.7%.

Characterization of Gaseous and Particulate Phase Polycyclic Aromatic Hydrocarbons Emitted During Preharvest Burning of Sugar Cane in Different Regions of Kwa-Zulu Natal, South Africa.

Biomass burning is a significant anthropogenic source of air pollution, including the preharvest burning of sugar cane. These burn events result in atmospheric emissions, including semivolatile organic compounds, that may have adverse impacts on air quality and human health on a local, regional, and even a global scale. Gaseous and particulate polycyclic aromatic hydrocarbon (PAH) emissions from various sugar cane burn events in the province of Kwa-Zulu Natal in South Africa were simultaneously sampled using a portable denuder sampling technology, consisting of a quartz fiber filter sandwiched between two polydimethylsiloxane multichannel traps. Total gas and particle phase PAH concentrations ranged from 0.05 to 9.85 µg m-3 per individual burn event, and nine PAHs were quantified. Over 85% of all PAHs were found to exist in the gas phase, with smaller two- and three-ring PAHs, primarily naphthalene, 1-methyl naphthalene, and acenaphthylene, being the most dominant and causing the majority of variance between the burn sites. The PAH profiles differed between the different burn events at different sites, emphasizing the significant influence that the crop variety, prevailing weather conditions, and geographical location has on the type and number of pollutants emitted. The potential carcinogenicity of the PAH exposure was estimated based on toxic equivalency factors that showed varying risk potentials per burn event, with the highest value of 5.97 ng m-3 . Environ Toxicol Chem 2023;42:778-792. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Regional Distribution of Atmospheric Organophosphate Tri-/Diesters in the Pearl River Delta: Possible Emission, Photo-degradation, and Atmospheric Transportation.

The regional characteristics of atmospheric organophosphate triesters (OPEs) and organophosphate diesters (Di-OPs) in the Pearl River Delta (PRD) were investigated by passive air samplers mounting quartz fiber filters. The analytes were found on a regional scale. Atmospheric OPEs, semi-quantified using sampling rates of particulate-bonded PAHs, were in the range of 537-2852 pg/m3 in spring and in the range of 106-2055 pg/m3 in summer, with tris(2-chloroethyl)phosphate (TCEP) and tris(2-chloroisopropyl)phosphate as the main components. While atmospheric Di-OPs were semi-quantified using sampling rates of SO42-, in the range of 22.5-5576 pg/m3 in spring and in the range of 66.9-1019 pg/m3 in summer, with di-n-butyl phosphate and diphenyl phosphate (DPHP) being the main Di-OPs. Our results indicated that OPEs were mainly distributed in the central part of the region, which might be ascribed to the distribution of industry related to OPE-containing products. In contrast, Di-OPs were scattered in the PRD, suggesting local emission from their direct industrial application. Significantly lower levels of TCEP, triphenyl phosphate (TPHP), and DPHP were detected in summer than in spring, implying that these compounds might be partitioned off particles as the temperature increased and due to possible photo-transformation of TPHP and DPHP. The results also suggested the long-distance atmospheric transportation potential of Di-OPs.

Characterization of offline analysis of particulate matter with FIGAERO-CIMS

Abstract. Measurements of the molecular composition of organic aerosol (OA) constituents improve our understanding of sources, formation processes, and physicochemical properties of OA. One instrument providing such data at a time resolution of minutes to hours is the chemical ionization time-of-flight mass spectrometer with filter inlet for gases and aerosols (FIGAERO-CIMS). The technique collects particles on a filter, which are subsequently desorbed, and the evaporated molecules are ionized and analyzed in the mass spectrometer. However, long-term measurements using this technique and/or field deployments at several sites simultaneously require substantial human and financial resources. The analysis of filter samples collected outside the instrument (offline) may provide a more cost-efficient alternative and makes this technology available for the large number of particle filter samples collected routinely at many different sites globally. Filter-based offline use of the FIGAERO-CIMS limits this method, albeit to particle-phase analyses, which is likely at a reduced time resolution compared to online deployments. Here we present the application and assessment of offline FIGAERO-CIMS, using Teflon and quartz fiber filter samples that were collected in autumn 2018 in urban Beijing. We demonstrate the feasibility of the offline application with a “sandwich” sample preparation for the over 900 identified organic compounds with (1) high signal-to-noise ratios, (2) high repeatability, and (3) linear signal response to the filter loadings. Comparable overall signals were observed between the quartz fiber and Teflon filters for 12 and 24 h samples but with larger signals for semi-volatile compounds for the quartz fiber filters, likely due to adsorption artifacts. We also compare desorption profile (thermogram) shapes for the two filter materials. Thermograms are used to derive volatility qualitatively based on the desorption temperature at which the maximum signal intensity of a compound is observed (Tmax⁡). While we find that Tmax⁡ can be determined with high repeatability (±5.7 ∘C) from the duplicate tests for one filter type, we observe considerable differences in Tmax⁡ between the quartz and Teflon filters, warranting further investigation into the thermal desorption characteristics of different filter types. Overall, this study provides a basis for expanding OA molecular characterization by FIGAERO-CIMS to situations where and when deployment of the instrument itself is not possible.

Inhibition behavior of milling hole outlet defects inhibition on quartz fiber polyimide composite through LN2 inner cooling

The helical milling hole process of quartz fiber reinforced polyimide composites (QFRP) aimed to remove high-strength fiber and low-strength resin through thermodynamic interaction. But the defects, especially delamination at hole outlet, were difficult inhabited because of heterogeneous and anisotropic of composite. A mechanics model of milling hole force of QFRP was established by considering the shearing force of single fiber and temperature. A liquid nitrogen (LN2) inner-cooling machining equipment was employed for cryogenic milling hole testes. Compared with the conventional dry milling hole, the processed composite surface morphologies, cutting temperature, and milling force were investigated at hole outlet in detail. The study results show the predict values of the established model are compared and verified through the experimental measurement. And the cryogenic coolant processes can improve the composite mechanics properties, milling forces, and cutting heat. The composite can be completely chip breaking in cryogenic cooling, and the burr and delamination are effectively inhabited at hole outlet. Meanwhile, the rapid decline of cutting force and lower interlamination bonding force problems can be solved by the cryogenic cooling cutting. And the fiber avoidance can be improved through the increased tangential force, and the fiber can be efficiency chip breaking under the bigger tangential force. In addition, LN2 cooling can inhabit the cutting high temperature and increase the bonding force, the delamination defect of composite can be adequately improved in cryogenic.

Block copolymer functionalized quartz fibers/cyanate ester wave-transparent laminated composites

A block copolymer of PDMS- b -PGMA is synthesized by polymerizing glycidyl methacrylate (GMA) via reversible addition-fragmentation chain transfer (RAFT) polymerization applying a polydimethylsiloxane (PDMS) based macro-RAFT agent, which is then performed to functionalize the quartz fibers (QFs@PDMS- b -PGMA) via a simple coating process. Finally, the QFs@PDMS- b -PGMA/bisphenol A dicyanate ester (BADCy) wave-transparent laminated composites are fabricated by high-temperature molding. Nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and size exclusion chromatography (SEC) demonstrate the successful preparation of PDMS- b -PGMA with expected structure. When the molar mass and coating amount of PDMS- b -PGMA are respectively 8100 g/mol and 2.0 wt.%, QFs@PDMS- b -PGMA/BADCy wave-transparent laminated composites present optimal mechanical properties and wave-transparent performance. The interlaminar shear strength (ILSS) and flexural strength are 53.6 and 552.0 MPa, respectively. Meanwhile, the dielectric constant and dielectric loss values are 2.61 and 0.0028 at 1 MHz (wave transmittance of 93.8%), showing good stability at different frequencies (10 2 -10 6 Hz and 8.4-12.4 GHz) and temperatures (25-250 °C).

Co-Optimizing Insulative and Mechanical Properties of Quartz Fabric Reinforced Phenolic Composites by a Compromising Porous Structure for Thermal Insulation

Introducing porosity into structures is recognized as a practical strategy to achieve lightweightness and insulation for ablatives, but reduced matrix density leads to the weakening of mechanical and anti-ablation performances. Herein, a trade-off design of the porous structure is developed for integrating high-strength, insulation, and anti-ablation abilities into mid-density nanoporous phenolic composites (NPC). Benefiting from a narrow nanopore size (20–62 nm) of the matrix, thermal conductivity of NPC can be effectively limited within 0.079–0.115 W/(m·K), while showing a mid-density of 0.89–1.04 g/cm3. Meanwhile, NPC shows a considerable axial tensile strength of 130.2–177.8 MPa and out-of-plane compressive strength of ∼300 MPa due to the compromising porosity (34–62%) and reinforcing of the 3D needle-punched quartz fiber preform. Besides, NPC exhibits excellent oxidation resistance in static radiation heating (1000 °C) and outstanding insulation and ablation resistance under an oxy-acetylene heat flux of 1.76 and 4.18 MW/m2 with the linear ablation rates of ∼0.102 and ∼0.185 mm/s, respectively. The results will further promote the development and application of phenolic ablatives in extreme re-entry environments.

Restoration of a Textile Artefact: A Comparison of Cleaning Procedures Applied to a Historical Tapestry from the Quirinale Palace (Rome)

The cleaning of textile artefacts and in particular historical tapestries is generally carried out using standard methods. Different cleaning procedures, including a new method based on a hydro-aspiration mechanism, recently developed by restorers with the aim of improving the efficiency of the cleaning system, were applied to a historical tapestry belonging to the lower edge of one of the tapestries of the “Ulysses Stories” series exhibited at the Quirinale Palace (Rome). The tapestry was made of wool and silk and has precious decorations made of metal yarns, which are particularly fragile. The new cleaning system was compared with the traditional methods commonly used by restorers for tapestry cleaning. For this purpose, the quantity and chemical composition of the particles removed and collected on quartz fibre filters by applying the different cleaning systems, were estimated by means of analytical techniques, such as IC (Ion Chromatography) for the quantification of the ionic species collected into the rinsing water, the TOT (Thermal Optical Transmittance) method for the quantification of the carbonaceous particles and SEM-EDX (Scanning Electron Microscopy coupled to Energy Dispersive X-ray Spectroscopy) for yarn morphological characterization and elemental analysis of the deposited particles. The objective of this study is to identify the correct cleaning method to apply to the polymaterial tapestry and, in particular, to the gilded silver and gold metallic yarns, whose conservation state requires the preservation of the “self-protection” patina necessary for the future exhibition inside the Quirinale Palace. The new hydro-aspiration method was found to be more efficient in removing dirt and preserving the structure of the metallic threads being in this way less invasive in detaching the fragile surface patina and at the same time more effective in removing dirt.

Wafer-scale controlled growth of MoS2 by magnetron sputtering: from in-plane to inter-connected vertically-aligned flakes

Recently, Molybdenum disulfide (MoS2) has attracted great attention due to its unique characteristics and potential applications in various fields. The advancements in the field have substantially improved at the laboratory scale however, a synthesis approach that produces large area growth of MoS2 on a wafer scale is the key requirement for the realization of commercial two-dimensional (2D) technology. Herein, we report tunable MoS2 growth with varied morphologies via radio frequency magnetron sputtering by controlling growth parameters. The controlled growth from in-plane to vertically-aligned (VA) MoS2 flakes has been achieved on a variety of substrates (Si, Si/SiO2, sapphire, quartz, and carbon fiber). Moreover, the growth of VA MoS2 is highly reproducible and is fabricated on a wafer scale. The flakes synthesized on the wafer show high uniformity, which is corroborated by the spatial mapping using Raman over the entire 2-inch Si/SiO2 wafer. The detailed morphological, structural, and spectroscopic analysis reveals the transition from in-plane MoS2 to VA MoS2 flakes. This work presents a facile approach to directly synthesize layered materials by sputtering technique on wafer scale. This paves the way for designing mass production of high-quality 2D materials, which will advance their practical applications by integration into device architectures in various fields.

Airborne microplastics in a suburban location in the desert southwest: Occurrence and identification challenges

Microplastics are rapidly emerging anthropogenic stressors that pose a potential threat to ecosystems and human health. While the ubiquitous nature of microplastics in water has been well documented, studies on their distribution in the air are limited. Measuring microplastics, as a component of atmospheric particulate matter, is important in assessing air pollution impacts within a breathing zone. Here we investigate and present results for the occurrence of microplastics in suspended particulate matter in Tempe, a suburban location in Arizona. Samples were collected from Oct 28th, 2020, to Nov 1st, 2021, on quartz fiber filters using a high-volume air sampler, and processed with microplastics counted under an optical microscope to obtain quantitative information of their presence and distribution in the atmosphere. Microplastics were present in all collected suspended particulate samples ranging from between 0.02 and 1.1 microplastics/m3 (average concentration of 0.2 microplastics/m3) with the size range of (5–5000) μm. Fibrous microplastics were the most prevalent accounting for a large majority (≥82%) of the microplastics suspended in air in all samples. To characterize the type of microplastics present, micro-Raman spectroscopy was used to identify the chemical composition of microplastics. Chemical characterization results revealed an array of polymers for the airborne microplastics. The most abundant identified polymer was polyvinyl chloride (19%). However, many micro-Raman spectra lacked characteristic peaks, making the chemical identification process more challenging. Laboratory experiments simulating weathering of microplastics were performed to understand how microplastics change under weathering processes; these experiments revealed that Raman spectra of microplastics change over time due to weathering processes.

Структура кварцевых волокон с медными покрытиями после вакуумной термической обработки

Using X-ray diffraction and differential scanning calorimetric analysis, we investigated the struc-ture and the effect of heat treatment in vacuum on the physical and mechanical properties of quartz fibers with a copper coating. The results of X-ray phase analysis show that at temperatures up to 1000 °C quartz is X-ray amorphous; however, the method of differential scanning calorimetry turned out to be more sensitive to changes in the properties of the material. It was found that at a heating rate of 10 °C/min, a crystal structure is formed in quartz fibers in the temperature range of 630-1000 °C during 30 minutes, which leads to a significant deterioration of physical and mechanical properties. This effect was confirmed at specific temperatures with the help of a scanning electron microscope.