Polystyrene Fibers Research Articles

Effects of Electrospinning Parameters on the Morphology of Electrospun Fibers

Hydrophobic electrospun membranes have a lot of applications in different fields. It is very difficult to increase the hydrophobicity of membranes for a specific application. This study investigates the effects of various electrospinning parameters on the morphology and hydrophobicity of polystyrene (PS) electrospun membranes. Polystyrene fibers were used as a reference for the study. Different parameters such as polymer concentrations, diameter of needles, and applied voltage were tested to study the influence on the hydrophobicity of electrospun fibers. Polystyrene fibers were electrospun at different concentrations from 5 to 20 wt.%, needles with a diameter from 0.5 to 3 mm were used, and voltage was applied between 8.06–16.05 kV. The surface morphology of polystyrene fibers and hydrophobicity were studied with a scanning electronic microscope and contact angle measurements. Based on the results of the study, higher polymer concentrations and voltages produce thinner fibers and more hydrophobic membranes. The results of this paper can be applied to the fabrication of different characteristic membranes for specific applications like water conservation, purification, and other fields.

The Ability of Gastropods of Lake Baikal to the Feeding and Excretion of Microplastic Particles with Different Morphological Structures

Studies of the pollution of Lake Baikal with microplastic particles have been started quite recently. Almost all research is focused on the assessment of surface water pollution, while the impact of microplastics on Baikal organisms remains unexplored. We conducted a laboratory experiment involving three species of gastropod mollusks, the Palearctic Lymnaea stagnalis (L., 1758) and Radix auricularia (L., 1758), as well as the Baikal endemic Benedictia baicalensis (Gerstfeldt, 1859). Two types of microplastics were used in the experiment: fragments of polystyrene and polyester fibers, prepared independently in the laboratory. These plastic particles, along with the food mixture, were placed in aquariums with mollusks. In total, as a result of the experiment, 386 preparations with mollusk excrement were obtained, of which 144 preparations were for the Radix auricularia species, 176 for the Lymnaea stagnalis species, and 67 for the Benedictia baicalensis species, the experiment with the latter species was carried out only with microplastic fragments. All preparations were analyzed according to the degree of fluorescence. The data were statistically processed using Spearman’s rank correlation coefficient. The data obtained allowed us to conclude that gastropods of these species are able to absorb microplastic particles and remove them from the body. However, the rate of removal of microplastic particles from the body of a mollusk is species-specific, and also directly depends on the morphological structure of microplastic particles.

Floor impact sound insulation performance of Korean domestic cross-laminated timber floors and the influence of resilient materials' dynamic stiffness

In this study, the floor impact sound insulation performance of floors made of korean domestic cross-laminated timber panels and with a resilient layer under concrete topping was evaluated. The properties of resilient materials used in the floors were measured to evaluate their influence on floor impact sound insulation performance. The results indicate that the highest reduction levels were provided by glass fiber, expanded polystyrene and wood fiber, in diminishing order, for both heavy-weight and light-weight floor impact sounds. Through the evaluation of dynamic stiffness and single-number quantities, a high correlation was observed at 125 Hz and 500 Hz for heavy-weight floor impact sounds and across all octave bands for light-weight floor impact sounds. The analysis of dynamic stiffness and single number quantity revealed a high correlation in both heavy weight and light weight floor impact sound. Lower dynamic stiffness was confirmed to be advantageous for reducing floor impact noise.

Influence of Mixed Solvent in the Morphology and Hydrophobicity of Electrospun Polystyrene Porous Fibers.

Electrospun polystyrene (PS) fibers are produced using a mixed solvent of chloroform and n,n-dimethylformamide (DMF) to investigate the influence of the solvent ratio on the fiber surface morphology and contact angle of the obtained mats. Electrospinning is a simple processing technique for producing fibers with diameters in the range of nanometers to a few micrometers. When using the different solvent ratios for this process, porous PS membranes are created due to nonsolvent and thermally induced phase separation (N-TIPS). The morphology of the fibers is analyzed through scanning electron microscopy (SEM), which showed that fibers have diameters between 200nm and 6µm. SEM also revealed that the pores present on the surface of the fibers vary from densely compacted and well-formed nanopores with diameters in the range of 20-50nm to larger pores with sizes of ≈100-200nm. The pore size varied with different solvent ratios. The surface area is analyzed using the Brunauer-Emmett-Teller (BET) method and found that the polymeric fibers have a high surface area (≈35 m2g-1). The fibers with such morphology are highly hydrophobic, with a contact angle higher than 143°. These materials are excellent candidates for applications in textiles, filtration, and biomedical fields.

Oil Sorption Properties of Centrifugally Spun Polyisobutylene-Based Thermoplastic Elastomer Microfibers

Fiber-based sorbent materials are an essential part of containing oil spills, thus preventing ecological damage. Poly(styrene-b-isobutylene-b-styrene) thermoplastic elastomer fibers were successfully produced by centrifugal spinning. Scanning electron microscopy revealed that the fibers were bead free and smooth-surfaced, with an average fiber diameter of 5.9 ± 2.3 μm. Contact angle measurements proved the highly hydrophobic (water contact angle of 126.8 ± 6.4°) and highly oleophilic nature of the fiber mat. The sorption and retention capacities of the fiber mat were tested for various oils and benchmarked against polypropylene as the industry standard and polystyrene, which is widely used in the literature. The oil uptake of the fiber mat showed a strong correlation with the viscosity of the oil, resulting in sorption capacities of 10.1 ± 0.8 g/g for sunflower oil, 19.9 ± 2.1 g/g for motor oil, and 23.8 ± 1.8 g/g for gear oil. Oil–water separation tests were also conducted, resulting in ~100% oil removal. The thermoplastic elastomer fiber mat outperformed the industry standard; however, the polystyrene fiber mat demonstrated the best oil sorption performance.

Evaluation of Machine Learning and Traditional Methods for Estimating Compressive Strength of UHPC

This research provides a comparative analysis of the optimization of ultra-high-performance concrete (UHPC) using artificial neural network (ANN) and response surface methodology (RSM). By using ANN and RSM, the yield of UHPC was modeled and optimized as a function of 22 independent variables, including cement content, cement compressive strength, cement type, cement strength class, fly-ash, slag, silica-fume, nano-silica, limestone powder, sand, coarse aggregates, maximum aggregate size, quartz powder, water, super-plasticizers, polystyrene fiber, polystyrene fiber diameter, polystyrene fiber length, steel fiber content, steel fiber diameter, steel fiber length, and curing time. Two statistical parameters were examined based on their modeling, i.e., determination coefficient (R2) and mean square error (MSE). ANN and RSM were evaluated for their predictive and generalization capabilities using a different dataset from previously published research. Results show that RSM is computationally efficient and easy to interpret, whereas ANN is more accurate at predicting UHPC characteristics due to its nonlinear interactions. Results show that the ANN model (R = 0.95 and R2 = 0.91) and RSM model (R = 0.94, and R2 = 0.90) can predict UHPC compressive strength. The prediction error for optimal yield using an ANN and RSM was 3.5% and 7%, respectively. According to the ANN model’s sensitivity analysis, cement and water have a significant impact on compressive strength.

Prediction of Ultra-High-Performance Concrete (UHPC) Properties Using Gene Expression Programming (GEP)

In today’s digital age, innovative artificial intelligence (AI) methodologies, notably machine learning (ML) approaches, are increasingly favored for their superior accuracy in anticipating the characteristics of cementitious composites compared to typical regression models. The main focus of current research work is to improve knowledge regarding application of one of the new ML techniques, i.e., gene expression programming (GEP), to anticipate the ultra-high-performance concrete (UHPC) properties, such as flowability, flexural strength (FS), compressive strength (CS), and porosity. In addition, the process of training a model that predicts the intended outcome values when the associated inputs are provided generates the graphical user interface (GUI). Moreover, the reported ML models that have been created for the aforementioned UHPC characteristics are simple and have limited input parameters. Therefore, the purpose of this study is to predict the UHPC characteristics while taking into account a wide range of input factors (i.e., 21) and use a GUI to assess how these parameters affect the UHPC properties. This input parameters includes the diameter of steel and polystyrene fibers (µm and mm), the length of the fibers (mm), the maximum size of the aggregate particles (mm), the type of cement, its strength class, and its compressive strength (MPa) type, the contents of steel and polystyrene fibers (%), and the amount of water (kg/m3). In addition, it includes fly ash, silica fume, slag, nano-silica, quartz powder, limestone powder, sand, coarse aggregates, and super-plasticizers, with all measurements in kg/m3. The outcomes of the current research reveal that the GEP technique is successful in accurately predicting UHPC characteristics. The obtained R2, i.e., determination coefficients, from the GEP model are 0.94, 0.95, 0.93, and 0.94 for UHPC flowability, CS, FS, and porosity, respectively. Thus, this research utilizes GEP and GUI to accurately forecast the characteristics of UHPC and to comprehend the influence of its input factors, simplifying the procedure and offering valuable instruments for the practical application of the model’s capabilities within the domain of civil engineering.

Advancing reinforcement of sustainable gypsum composites: High-performance design by reusing waste materials

This study tends to optimize and develop an innovative gypsum material by incorporating hybrid waste compounds. Using a Doehlert design, this work explores the effects of introducing paper (X1), polystyrene (X2), and polyester fibers (X3), as well as their interactions, on gypsum's thermophysical and mechanical behavior. Bulk density, thermal conductivity, flexural strength, compressive strength, and the fire resistance test were performed on the developed formulations. Statistical analysis emphasizes the significant influence of all process variables on gypsum properties. Polyester fibers notably enhance flexural strength when combined with the cooperative effect of paper and polystyrene wastes, which strike a balance between physical and mechanical characteristics. The optimum formulation parameters lead to a significant 33% decrease in bulk density, a 43% reduction in thermal conductivity, a notable 42% increase in flexural strength, and a significant reduction in compressive strength of around 50%, but still meet the 2 MPa standard. The new samples show ductile behavior, highlighting gypsum's potential as a load-bearing material with excellent thermal insulation properties and impressive fire resistance. This research significantly improves our understanding of the effectiveness of a gypsum compound incorporating waste in a hybrid manner, bringing this approach into line with sustainable development objectives.

Electrospun polystyrene/asphaltene fiber for selective separation of oil from water surface

To deal with the challenges of oil spills and their harms, fabricating superhydrophobic adsorbents with high sorption properties is a significant issue. For the first time, asphaltene was involved in polystyrene polymer using the electrospinning method to produce efficient fibers for oil adsorption from water. The polystyrene-asphaltene composite fibers showed a considerable increase in the porosity, surface area, water contact angle, and hydrophobic-lipophilic nature compared to polystyrene fibers. The maximum adsorption capacity of polystyrene-asphaltene fibers was 50–120% higher than that of polystyrene fibers. The oil adsorption on the composite sorbents was fast, and the steady state condition was reached in 22 min. The kinetic data fit the intraparticle kinetic model well, representing three stages of the adsorption process. Asphaltene, as a cost-effective, abundant component, induces unique properties in the polystyrene-asphaltene fibers and can be considered a proper choice for oil spill cleanup.

Hydrophobic or hydrophilic microhelices: Crafting surfaces with electrospun magnetic polystyrene fiber and an innovative top‐down technique

AbstractMicrohelices are important structures capable of overcoming low Reynolds number limitations and can be used in various applications. The fabrication of such microhelices is a challenge as existing fabrication techniques are restrictive in material choices and require sophisticated equipment. In this work, we demonstrate a simple top‐down approach to fabricate microhelical structures using surface modification of helical electrospun fibers to produce both hydrophilic, silica‐coated (Si‐HMPF), and hydrophobic, caramel sol‐based (Ca‐HMPF) magnetic microhelices post‐modification. The glassy coating obtained on the surface in both cases facilitated obtaining magnetic microhelices via mechanical fracture of the fibers by grinding at room temperature. SEM images of the samples confirm the successful fabrication of microhelical structures which resemble the popular microswimmer morphology. The FTIR and VSM characterization were performed to study the functional groups present and the magnetic nature of the fabricated microhelices. The thermal stability of the samples was investigated using DSC and TGA studies. Both hydrophilic and hydrophobic magnetic microhelices were successfully fabricated through a simple sol‐based coating technique and confirmed by a wettability study.Highlights Helical microstructures are an important classification of micro/nanomaterial synthesis. A simple method for the fabrication of magnetic polymeric microhelices is proposed and discussed in detail. The current challenges in fabricating such structures are discussed. The advantages of using a simple surface modification technique is summarized.

Best Practices to Directly Assess Heterogeneous Singlet Oxygen Photosensitization by Phosphorescence

AbstractLiterature proves that the direct detection of 1O2(1Δg) at the solid gas interface is systematically performed from its phosphorescence using high intensity excitation sources (i.e., lasers), which lead to quasi‐ubiquitous chemical problems, such as sensitizer degradation, and photophysical counter‐active issues such as ultrafast exciton migration, singlet‐singlet and triplet‐triplet annihilation, and thermally activated delayed fluorescence mediated by 1O2(1Δg). To avoid these inconveniences, low excitation intensity is required but leads to serious analytical challenges. The best practices to reliably detect 1O2(1Δg) phosphorescence at various interfaces using a standard excitation source and near‐IR detector. The two main practices consist in a gas purging test for reliable identification of 1O2(1Δg), and in a particularly fine optimization of the angle made by excitation beam versus substrate plane. These practices are applied to porphyrin sensitizers H2TPP and ZnTPP, either neat or physiosorbed on glass, quartz, paper and hospital bandages, graphene oxide (GO), and embedded inside electrospun polystyrene fibers and spin coated poly(methyl methacrylate) films. Porphyrin‐based metal‐organic framework PCN‐224, freshly activated, is also examined.

Synthesis of Polystyrene Fiber Membranes Prepared by Electrospinning: Effect of AgNO3 on the Microstructure

<p>Polystyrene (PS) is commonly employed in insulation, packaging, filters, and medical equipment, with recent studies exploring its potential in fiber membrane production. The electrospinning technique is discussed to synthesize PS fiber membranes with high porosity and controllable diameter. Additionally, incorporating silver nitrate into PS composite fibers is explored for enhanced functionalities such as catalytic activity, high electrical conductivity, and antibacterial activity. However, PS composite fiber membranes with silver nitrate (AgNO<sub>3</sub>) metal variations are rarely observed. This research aims to modify the microstructure of PS fiber membranes produced using electrospinning by adding silver nitrate (AgNO<sub>3</sub>) with varying concentrations. PS-Ag fiber membranes are produced using N,N-dimethylformamide (DMF) solvent, which serves as a solvent and a reducing agent for Ag. The results show that the effect of Ag affected the diameter of the PS-Ag fiber membrane, with an average diameter of around 3.67 - 6.93 micrometers. Degradation occurred in these samples at a strong broadening peak near ~1300 cm<sup>-1</sup> until ~1600 cm<sup>-1</sup> from the Raman results. The FTIR results show that the wavelength of ~3500 cm<sup>-1</sup> indicated the presence of OH. The presence of OH indicates that the PS-Ag fiber membrane has the potential for water filtration application</p>

Fabrication of electrospun ultrafine fibreous membrane and their application in paraben adsorption

Electrospinning provides a simple and versatile method for generating ultrafine fibers from a rich variety of materials that include polymers, composites, and ceramics. Find applications in various fields, including tissue engineering, filter media, reinforcement in nanocomposites, and micro/nano-electro-mechanical systems. In this study the polystyrene fibers in 10%, 20% and 30% (w/v) in THF: DMF solvents were characterized by ATR-FTIR, AFM and SEM. The obtained fibers exhibited a smooth surface with fine structures, emphasizing a ribbon-like morphology with bead-like features within the range of 3 µm to 5 µm in diameter. The aim of this study was to extract the parabens at optimized conditions such as pH, adsorbent dose, contact time and the elution of solvent. To examine the mechanism of adsorption kinetics, the two most commonly used kinetics models (pseudo-first order and pseudo-second order) were employed to test experimental data along with the Morris-Weber diffusion model. The obtained data showed that the maximum sorption efficiency obtained at pH 3.0, adsorbent dose optimized as 10 mg of fiber with time of 24 hours, the methanol was sufficient to elute paraben from fibers met. The experimental data of the adsorption followed by first-order reaction with a mass transfer-controlled diffusion mechanism

Mathematical Modelling of Scission Electrospun Polystyrene Fibre by Ultrasonication Scission

This study investigates the effects of time and diameter on the final scission length of the electrospun polystyrene (PS) fibres, whereby the fibres were ultrasonicated for 1, 2, 3, 4, and 8 minutes. The ultrasonic probe stimulates bubble cavitation followed by bubble implosion as scission occurs. Factors affecting the scissionability of the electrospun PS fibres are primarily the diameter of the fibre and the sonication run time. The scission final fibre length range is approximately 23.7 µm to 1.1 µm. SEM images show that the fibre breaks into shorter lengths as sonication run time increases. Conversely, fibre diameter exhibits a positive relationship with fibre length. The model gives an R-squared value of 0.44 and 0.59 for linear and non-linear regression, thus suggesting that the non-linear model provides a better fit for the data. The validation of the model is achieved by conducting a hypothesis test. Through hypothesis testing, the mean of the experimental average final length value and the predicted average fibre length from the regression model were not significant, indicating that the model can generally predict a relatively accurate average final fibre length value. The model derived from this study enables researchers to estimate the time required to sonicate the PS fibre (with a specific diameter) to achieve the short fibre length needed in their application. As research progresses, refining the model and incorporating additional parameters will be essential to ensure the broad reliability and applicability of these models across a variety of practical contexts.

Activated carbon-decorated electrospun polystyrene fibers for highly efficient removal of hazardous crystal violet dye from water

This study focuses on the synthesis of activated carbon (AC) from pomegranate peels biowaste and successful incorporation into polystyrene fibers (PSFs) by electrospinning process, yielding composite electrospun fiber membrane known as AC-PSFs. To gain insights into the characteristics of the fabricated electrospun fiber composite, a comprehensive characterization was conducted. To verify the role of AC in enhancing adsorption performance of PSFs to remove cationic crystal violet dye (CV) from aqueous solutions, batch adsorption technique was used. Notably, the AC-PSFs composite, containing 10% of AC, exhibited 465% high adsorption capacity compared to neat PSFs. The maximum Langmuir adsorption capacities obtained for CV dye was 65.14, 67.16 and 71.28 mg/g for PSFs and 388, 394.61 and 402.78 mg/g for AC-PSFs, at a temperature of 298, 303, and 308 K, respectively. The adsorption of CV dye onto PSFs and AC-PSFs closely followed the Langmuir isotherm model, while the kinetic adsorption fitted well with PSO model. AC-PSFs is a highly reusable adsorbent, retaining a 99% removal efficiency after using it for ten consecutive cycles, exemplifying its significant potential for long-term applications. Furthermore, the fabricated AC-PSFs composite offers the advantages of facile fabrication, excellent reusability, and easy handle, thereby establishing itself as a promising adsorbent for the efficient removal of cationic dyes from polluted water.

Influence of fiber types on the properties of the artificial cold-bonded lightweight aggregates

Abstract The cold-bonded pelletizing method is often employed in aggregate production since it uses less energy and helps reduce issues with gas emissions, contributing to economic and environmental benefits. In this study, fly ash was chosen as the raw material and used to partially replace cement in manufacturing artificial aggregate. Three types of fibers (polypropylene, polystyrene, and glass fiber) in different volume fractions were used to investigate their effect on the properties of the artificial cold-bonded lightweight aggregate. After the manufacturing process, aggregates were cured with a 28-day water curing. Their specific gravity, water absorption, density, impact value, and crushing value were tested to analyze the properties of the cold-bonded artificial aggregate. Results show that adding various volume fractions of PS, glass, and PP fibers during pelletization caused a more stable generation of aggregates with enhanced mechanical and physical properties.

Hollow Hafnium Oxide (HfO2) Fibers: Using an Effective Combination of Sol-Gel, Electrospinning, and Thermal Degradation Pathway.

In recent years, hafnium oxide (HfO2) has gained increasing interest because of its high dielectric constant, excellent thermal stability, and high band gap. Although HfO2 bulk and film materials have been prepared and well-studied, HfO2 fibers, especially hollow fibers, have been less investigated. In this study, we present a facile preparation method for HfO2 hollow fibers through a unique integration of the sol-gel process and electrospinning technique. Initially, polystyrene (PS) fibers are fabricated by using electrospinning, followed by dipping in a HfO2 precursor solution, resulting in HfO2-coated PS fibers. Subsequent thermal treatment at 800 °C ensures the selective pyrolysis of the PS fibers and complete condensation of the HfO2 precursors, forming HfO2 hollow fibers. Scanning electron microscopy (SEM) characterizations reveal HfO2 hollow fibers with rough surfaces and diminished diameters, a transformation attributed to the removal of the PS fibers and the condensation of the HfO2 precursors. Our study also delves into the influence of precursor solution molar ratios, showcasing the ability to achieve smaller HfO2 fiber diameters with reduced precursor quantities. Validation of the material composition is achieved through thermogravimetric analysis (TGA) and energy-dispersive spectroscopy (EDS) mapping. Additionally, X-ray diffraction (XRD) analysis provides insights into the crystallinity of the HfO2 hollow fibers, highlighting a higher crystallinity in fibers annealed at 800 °C compared with those treated at 400 °C. Notably, the HfO2 hollow fibers demonstrate a water contact angle (WCA) of 38.70 ± 5.24°, underscoring the transformation from hydrophobic to hydrophilic properties after the removal of the PS fibers. Looking forward, this work paves the way for extensive research on the surface properties and potential applications of HfO2 hollow fibers in areas such as filtration, energy storage, and memory devices.

Experimental Investigation of Mechanical Properties of Concrete Mix with Lightweight Expanded Polystyrene and Steel Fibers

The demand for lightweight aggregates in concrete compositions for diverse structural and non-structural applications in contemporary building construction has increased. This is to achieve a controllable low-density lightweight concrete, which reduces the overall structural weight. However, the challenge lies in achieving an appropriate strength in lightweight concrete while maintaining a lower unit weight. This research aims to evaluate the performance of lightweight concrete by integrating expanded polystyrene (EPS) as a partial replacement for coarse aggregate. Test specimens were cast by blending EPS with coarse aggregate at varying proportions of 0%, 15%, 30%, and 45%, while maintaining a constant water-to-binder ratio of 0.60. To enhance the bonding and structural capabilities of the proposed lightweight concrete mixes, reinforcement with 2% and 4% steel fibers by volume of the total concrete mix was incorporated. Silica fume was introduced into the mix to counteract the water hydrophobicity of EPS material and enhance the durability of lightweight concrete, added at a rate of 10% by weight of cement in all specimens. A total of 60 samples, including cylinders and beams, were prepared and cured over 28 days. The physical and mechanical properties of the lightweight EPS-based concrete were systematically examined through experimental testing and compared against a standard concrete mix. The analysis of the results indicates that EPS-based concrete exhibits a controllable low density. It also reveals that incorporating reinforcement materials, such as steel fibers, enhances the overall strength of lightweight concrete.

Recycled Polystyrene Waste to Triboelectric Nanogenerators: Volumetric Electromechanically Responsive Laminates from Same‐Material Contact Electrification

Millions of tonnes of polystyrene (PS) are produced annually, with only an estimated 12% being recycled. Herein, the upcycling of expanded or foamed PS waste into electromechanically responsive triboelectric laminates (TLs) is described. These TLs possess internal triboelectric dipoles offering an alternative to ferroelectric fluoropolymers, and, when manufactured into triboelectric nanogenerators (TENGs), are able to generate over 200 V and 12 μA from motion. This energy harvesting is enabled by electrospinning alternating layers of small and large diameter PS fibers, which upon friction establish an effective dipole moment within the TL. The PS‐TENG shows remarkable stability and is able to charge a 0.47 μF capacitor to 15 V in 200 s of vibration from same material contact electrification, with piezoelectric contact‐mode testing showing that a single PS laminate is comparable to state‐of‐the‐art piezoelectric fluoropolymers for overall electromechanical conversion.

Comparison of ZrO2 Particles and Polyaniline as Additives in Polystyrene-Based Sorbents for the Micro-Solid Phase Extraction of Psychoactive Drugs from Biofluids.

The intensive development of extraction methods based on μ-SPE extraction contributes to the increased interest in the synthesis of new sorption materials. This work presents the characterization of polystyrene fibers and polystyrene fibers blended with ZrO2 particles or polyaniline obtained by electrospinning and their use in the extraction of selected psychoactive drugs from biological samples. The characteristic of produced fibers is made by performing SEM images, measuring average fiber diameter, and examining their sorption abilities. Among the fibers based on pure polystyrene, tested in the first stage, the best sorption properties are demonstrated for the fibers obtained from a polystyrene solution in DMF with a concentration of 17.5 wt%. In the next stage, this material was modified with synthesized ZrO2 particles and polyaniline. Among the tested materials, the sorbent based on polystyrene with polyaniline shows the best sorption properties of the tested substances. The use of this material in the μ-SPE in a needle enables the extraction of selected compounds from aqueous and biological samples such as urine and human plasma.