Lumen Of Hollow Fiber Research Articles

A Study on Simulated Urine Absorption Behaviour of Kapok-Cotton Blended Nonwoven Web

ABSTRACT Textile waste materials such as chemical-based diapers are responsible for aggravating environmental pollution. It usually takes years to degrade naturally. The world is in constant need of some green alternative solutions without compromising on product performance. Cellulosic materials being highly absorbent and biodegradable in nature such as cotton, Kapok, jute, banana etc. have the potential to replace these synthetic materials. The present study investigates the simulated urine absorption and retention characteristics of 100% cotton and Kapok-cotton blended webs. The morphological characteristics of raw, scoured and rewetted Kapok fiber were first studied. The hollow Kapok fiber lumen was found to have collapsed after scouring. However, it regained its shape after re-wetting in simulated urine. Absorption capacity was found to be maximum at 50:50 Kapok-cotton ratio in the nonwoven web. Statistically, the t-test also corroborates the same result at a 5% significance level. The absorption rate (g/s) and retention (%) were also maximum for the same blend. With an increase in external pressure, the liquid retention was reduced. On comparing a 50:50 Kapok-cotton blended with a 100% cotton nonwoven fibrous web, the absorption capacity, rate, and retention are increased by 26.1%, 300%, and 13.5%, respectively.

Development of a disposable hollow fibre-solid phase microextraction device using chitosan functionalised MWCNTs and a polyoxometalate for the simultaneous extraction of angiotensin II receptor blocker drugs

ABSTRACT Valsartan and Losartan are two angiotensin II receptor blocker drugs used to treat heart failure and high blood pressure. A straightforward and disposable hollow fibre-solid phase microextraction device was developed to extract these drugs from real water and urine samples. A green sorbent was synthesised by functionalised MWCNTs with chitosan through a chemical route method. Besides, a polyoxometalate (Ni-CoWO4 nanoparticles) was prepared as a modifier using the hydrothermal procedure. Using the sol-gel strategy, the sorbent and modifier were reinforced in the hollow fibre pores and lumen. The approach leads to an increase in the sorbent coating stability on/in hollow fibre. The influential factors were optimised with an experimental design, indicating that pH, extraction time, and desorption time significantly affect the Valsartan and Losartan extraction. The linearity of the method to determine Valsartan and Losartan was 3.4–1850 and 3.1–1800 ng mL−1, with R squared of 0.9929 and 0.9947, respectively. The detection and quantification limits were lower than 0.9 ng mL−1 and 3.4 ng mL−1, respectively. The pre-concentration factors for determining Valsartan and Losartan with a concentration of 20 ng mL−1 were 654.2 and 546.3, respectively. The intra-day and inter-day RSDs were lower than 3.11% and 3.87% for measuring Valsartan and Losartan. The recoveries and RSDs for analysing spiked eal water and urine samples were between 91.8–97.8% and 3.16–4.10%, respectively.

Inner-selective polyethersulfone-polydimethylsiloxane (PES-PDMS) thin film composite hollow fiber membrane for CO2/N2 separation at high pressures

Carbon dioxide (CO2) is the dominant greenhouse gas (GHG) and thus CO2 capture from flue gas of power plants, the main anthropogenic source of emission, is a key approach to mitigating the climate change. Thin-film composite (TFC) membranes have received extensive research attention recently as a promising post-combustion CO2 capture (CO2/N2) technology owing to its energy-efficiency, design versatility and upscaling potential. However, studies with the most industrially relevant membrane configuration, the hollow fibers, are rather limited for this application. Herein, we developed an inner-selective polyethersulfone-polydimethylsiloxane (PES-PDMS) TFC hollow fiber membrane by inner coating PDMS in the lumen of PES hollow fibers and then pressurizing the hollow fibers for CO2/N2 separation. The optimal PES-PDMS TFC membrane can achieve a CO2 permeance of 2150 GPU and a CO2/N2 selectivity of 20 when the operating pressure was between 20–22 bar, which holds good potential for post-combustion CO2 capture. The high separation performance arises from a combination of the stretched PES and PDMS layers. The micro-deformation of both layers under high pressures at the lumen side could possibly reduce the selective layer thickness. It may also induce polymer chain orientation, increase the fractional free volume, and potentially create free volume with smaller sizes, thus enhancing the CO₂ permeability and CO₂/N₂ selectivity from the PDMS and PES layers.

Plugging of hollow fiber lumen by a gel: Threshold operating conditions unraveled by simulations

Membrane processes may experience gel plugs that require specific cleaning steps. This paper demonstrates with simulations how these plugs can occur. A physical model is used to describe the particular diffusive behavior of gels. This model is implemented in an OpenFOAM CFD simulation code to describe the dynamics of the gel layers when filtration is stopped. During this step of relaxation, it is shown that the gel can expand and lead to a plug with characteristic times in the order of minutes. The plugging is favored by a quick gel expansion and by a slow diffusion removal. The operating conditions leading to the gel plugging are analyzed and threshold conditions are unraveled. General practical recommendations on the process control are drawn from these results.

Application of hollow fiber-protected liquid-phase microextraction combined with GC-MS in determining Endrin, Chlordane, and Dieldrin in rice samples.

This paper introduces a novel and minimized sample preparation technique based on hollow fiber-protected liquid-phase microextraction that can be used in joint with gas chromatography-mass spectrometry (GC-MS) detection to extract three organochlorine pesticides-Endrin, Chlordane, and Dieldrin-from rice samples. To that end, a single-walled carbon nanotube (SWCNT) and a proper ionic liquid (IL) were ultrasonically dispersed and injected into the lumen of hollow fiber as the extraction phase for preconcentrating and extracting the target analytes from the rice samples. The effects of the type of nanoparticles, ILs, and desorption solvent on the efficiency of extracting the analytes were investigated based on the one-factor-at-a-time (OFAT) approach. In addition, other parameters influencing the extraction procedure were optimized using an experimental design that decreased the number of experiments, reagent consumption, and costs. Under optimized conditions, the limits of detection and quantification in determining mentioned pesticides varied between 0.019-0.029 and 0.064-0.098ng mL-1, respectively. The calibration graphs to measure Endrin, Chlordane, and Dieldrin were linear over the concentration range of 0.064-13.2, 0.098-16.7, and 0.092-11.4ng mL-1, respectively. The relative standard deviations for inter-day and intra-day analysis were below 7.06 and 4.75% for the triplicate determination of three organochlorine pesticides. Besides, the relative recoveries and standard deviations of Endrin, Chlordane, and Dieldrin for analyzing several Iranian rice samples were between 86.0-92.9% and 4.5-5.8%, respectively. The results were compared with other similar works in literature, proving that the proposed method is efficient and useful for routine monitoring of organochlorine compounds in food samples.

Effect of Flow Operation Modes on Removal of Acetic Acid from Oil Palm Frond Biomass Hydrolysate using Hollow Fiber Supported Liquid Membrane

Acetic acid (AA) is considered an inhibitor in the oil palm frond (OPF) biomass hydrolysate solution. It can reduce the microorganism activity during sugar fermentation using OPF solution. In the current study, a hollow fiber supported liquid membrane (HFSLM) system using hybrid polyethersulfone-graphene membrane support and organic liquid membrane phase of 0.5 M tri-n-octyl amine carrier in a 2-ethyl-1-hexanol diluent was used to remove the AA. The liquid membrane impregnation time and the flow operation modes of the feed and strip phases in the HFSLM configuration were investigated. Mode I was operated with the feed phase flow inside the hollow fiber (HF) lumen and the stripping phase flow at the shell side. In mode II, the feed phase entered at the shell side and the stripping phase at the lumen of the HF support. The best liquid membrane impregnation time was 4 hours, exhibiting the highest AA removal efficiency of 80% compared to 1 and 24 hours of impregnation time. The removal efficiency of the AA was 80.1% and 42.4% using mode I and mode II, respectively, at 8 hours of the supported liquid membrane (SLM) running time. HFSLM was applied to remove AA from real OPF biomass hydrolysate. It was found that the AA concentration had reduced from 6.83 to 2.01 g/L after the SLM process. The SLM process did not affect the concentration of other components, especially sugar compounds in the OPF biomass hydrolysate.

Application of MXene as a new generation of highly conductive coating materials for electromembrane-surrounded solid-phase microextraction

Abstract For the first time, highly conductive thickly layered two-dimensional titanium carbide (MXene) was applied as a new coating agent for electromembrane-surrounded solid-phase microextraction (SPME) of triadimenol and iprodione as two model analytes. Preparation of the desired coated electrode was carried out using electrophoretic deposition of MXene on the surface of platinum electrode. Characterization of the prepared coated electrode was conducted using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The coated electrode was located inside a hollow fiber membrane impregnated by 2-nitrophenyl octyl ether as the supported liquid membrane (SLM), while an aqueous solution was injected inside the hollow fiber lumen. Separation and quantification of the analytes were carried out using a gas chromatography instrument equipped with mass spectrometric detection. The effective parameters of the microextraction procedure comprising pHs of sample solution and the acceptor phase, composition of the SLM, extraction time, and the applied voltage were optimized using one-variable at-a-time method. Under the optimal conditions, the calibration curves of the analytes were linear (R 2 > 0.9973) in the range of 0.3–250.0 and 0.5–250.0 ng mL−1 for triadimenol and iprodione, respectively. The limit of detections was determined to be 0.10 and 0.15 ng mL−1 for triadimenol and iprodione, respectively. Repeatability and reproducibility of the method were evaluated by the calculation of intra-day and inter-day relative standard deviations (%). The applicability of the method was evaluated by quantitative analysis of the model analytes in environmental water samples. Relative recoveries in the range of 87.31–102.7% confirmed that the prepared coated electrode can be considered a reliable option in electromembrane-surrounded SPME techniques.

Influence of Draw Ratio and Take-Up Velocity on Properties of Ultrafiltration Hollow Fiber Membranes from Polyethersulfone

This study aimed to reveal the influence of the draw ratio and take-up speed on the pore size distribution and morphology of the hollow fiber ultrafiltration membrane selective layer. To this end, spinnerets with ring ducts of 1.8 and 1.3 mm were employed, whereas the external diameter of the obtained fiber was kept equal. Atomic force microscopy and scanning electron microscopy were employed to study the morphology of the selective layer. Liquid–liquid displacement porosimetry was used to determine the limiting pore size distribution. The produced polyethersulfone ultrafiltration membranes had a robust, sponge-like porous structure, permeance 1000 L/(m2·h·bar), smooth selective layer, and mean pore size 25 nm. It was found that limiting pore sizes are affected more by the change in the take-up speed, whereas the surface pore sizes, roughness, and morphology are controlled by the draw ratio. It was shown that excessive draw causes the selective layer stretching and crop-up of the porous sublayer. Consequently, the diameters of the spinneret ring duct and the bore needle should match the hollow fiber outer and lumen diameters, respectively.

Preconcentration and determination of five antidepressants from human milk and urine samples by stir bar filled magnetic ionic liquids using liquid-liquid-liquid microextraction-high-performance liquid chromatography.

A sensitive and straightforward liquid-liquid-liquid microextraction method was developed to preconcentrate and cleanup antidepressants, including mirtazapine, venlafaxine, escitalopram, fluoxetine, and fluvoxamine, from biological samples before analyzing with high-performance liquid chromatography. The essential novelty of this study is using magnetic ionic liquids as the extraction phase in the lumen of hollow fiber and preparing a liquid magnetic stir bar. In this method, polypropylene hollow fiber was utilized as the permeable membrane for the analyte extraction. Six magnetic ionic liquids consisting ofthe transition metal and rare earth compounds were synthesized and then hollow fiber lumen was injected as acceptor phase to extract the antidepressants. Besides, 3-pentanol as a water-immiscible solvent was impregnated in the hollow fiber wall pores. The effective factors in the method were optimized with the central composition design. The resultant calibration curves were linear over the concentration range of 0.8-400.0ng mL-1 (R2 ≥ 0.996). The method displayed the proper detection limit (0.11-0.24ng mL-1 ), the reasonable limit of quantification (≤0.79ng mL-1 ), wide linear ranges, high preconcentration factors (≥294.3), and suitable relative standard deviation (2.31-5.47%) for measuring antidepressant medications. Analysis of human milk and urine samples showed acceptable recoveries of 96.5-103.8% with excellent relative standard deviations lower than 5.95%.

Vacuum-assisted continuous flow electroless plating approach for high performance Pd membrane deposition on ceramic hollow fiber lumen

Pd-based membranes have wide applications in H2-related fields given their excellent selectivity in H2 separation. Despite their unique advantages, the fabrication of continuous and dense Pd membrane layer in the lumen side of the hollow fibers remains a great challenge. Herein, a vacuum-assisted continuous flow electroless plating (VCFELP) approach was developed to deposit a 4 μm-thick compact Pd membrane layer on the lumen (i.e., inner surface) of YSZ-Al2O3 composite hollow fiber with outer and inner diameter of 1.5 and 1.0 mm, respectively. The Pd membrane displayed hydrogen flux of ∼0.075 mol m−2 s−1 at 773 K and the nitrogen was undetectable through bubble flow meter and gas chromatograph. Furthermore, the stability and durability of the Pd membrane were significantly improved by the VCFELP approach with the aid of vacuum and continuous flow system. The outstanding membrane stability was verified by the 240-h long-term operation, with up to 24 cycles of H2–N2 gas exchange tests, 40 thermal cycle tests (from high to low temperature) and 20 pressure cycle tests. Furthermore, the Pd membrane showed sufficient stability and excellent reaction performance during the 120-h reaction run in the one-step oxidation of benzene to phenol using hydrogen and oxygen as co-reactants, achieving the benzene conversion and phenol selectivity of 23.5% and 91.6%, respectively.

BaTiO3-based thermistor hollow fibers prepared using a phase inversion spinning process for energy efficient gas sorption

Positive temperature coefficient of resistivity (PTCR) hollow fibers that exhibit self-regulating heating characteristics have potential applications in temperature-swing adsorption systems (TSA), such as CO2 recovery and drying of compressed air. La-doped BaTiO3 hollow fibers displaying a PTCR effect were produced by phase inverting a casting solution consisting of N-methly-2-Pyrrolidone, polymethyl methacrylate, polyvinylpyrrolidone, BaTiO3, TiO2, and La2O3 through a spinneret into a coagulating waterbath. This was followed by polymer debinding, high temperature sintering between 1350−1400 °C and annealing in air at 1175 °C to produce hollow fibers of the composition Ba0.9975La0.0025TiO3. Hydrothermal synthesis was implemented to deposit an adsorbent porous zeolite X layer within the hollow fiber lumen, which was confirmed by electron dispersive X-ray spectroscopy and CO2 adsorption at 0 °C. Hence, these materials can be applied to energy efficient TSA gas separation processes. The results are discussed in terms of hollow fiber microstructure, adsorption characteristics and electrical properties.

Analysis of basic drugs in biological samples using dynamic single-interface hollow fiber liquid-phase microextraction combined with fast electromembrane extraction

In this study, a combination of single-interface hollow fiber liquid-phase microextraction and electromembrane extraction was applied for the extraction of some basic drugs from biological samples. The extraction process was followed by the HPLC-UV instrument. In this dynamic system, 1-octanol was impregnated into the pores of hollow fiber wall as an acceptor phase, the sample solution (pH = 12.0) was pumped into the lumen of hollow fiber by a syringe pump, the extraction efficiency was improved by filling and emptying (25 times) of sample solution (step-1). The extracted analytes in the organic acceptor phase were back-extracted by a fast electromembrane extraction procedure (step-2). Effective parameters on the extraction efficiency of both methods were investigated and optimized. Under optimized conditions (organic acceptor phase: 1-octanol, sample solution volume: 1500 µL, flow rate: 2.0 mL min−1, the number of filling and emptying cycles: 25, voltage: 100 V, back-extraction time: 2 min, and aqueous acceptor phase: 100 mM HCl), the proposed method provided good linearity with determination coefficients ranging from 0.992 to 0.996 over a concentration range of 2.5–1000 ng mL−1. Extraction recoveries were obtained in the range of 65.1 and 88.8%, which resulted in preconcentration factors in the range of 32.6–44.4. The limits of detection were found to be within the range of 0.12–0.36 ng mL−1, while the corresponding repeatability ranged from 3.7 to 9.3% (n = 3). Finally, the optimized method was applied for the quantification of propranolol, diltiazem and, lidocaine in urine and, plasma samples with relative recoveries ranged between 94.1 and 105.4%, indicating the reliability of the method.

Reverse Micelle Hollow Fiber Liquid-Phase Microextraction Coupled with HPLC for the Determination of Q-Markers of Anthraquinones in Rhubarb and Their Plasma Protein Binding Rates

A three-phase hollow fiber liquid-phase microextraction based on reversed micellar supramolecule was developed and employed for the determination of quality markers of three anthraquinones in Rhubarb and their plasma protein binding rates. Moreover, the extraction mechanism of reversed micellar supramolecule and determination mechanism of plasma protein binding rate by the proposed method are both explored. In this procedure, n-nonanol was impregnated in the wall pores and reverse micelle of tetrabutylammonium chloride/n-nonanol filled in lumen of hollow fibers, which were covered with a thin salt film and used for the microextraction of target compounds prior to HPLC analysis. Important extraction parameters including extraction solvent type, reversed micellar supramolecule type and concentration, sample phase pH, salt concentration, stirring rate, extraction time, and binding time between active compound and plasma protein were investigated. Under the optimized conditions, limits of detection were 0.1–0.4 ng/mL with enrichment factors in the range of 54.2–100.7. The linearities were 0.5–500 ng/mL with r2 ≥ 0.9838. Satisfactory accuracies (relative recoveries 95.7–98.3%) were also obtained. The average plasma protein binding rates of rhein, chrysophenol, and physcion were 96.7%, 41.8%, and 46.7%, respectively. The results showed that the proposed procedure can not only extract and concentrate anthraquinones in Rhubarb, but also determine their plasma protein binding rates.

Thin-film composite hollow fibre membrane for low pressure organic solvent nanofiltration

Polyamide thin film membranes have shown outstanding performance in organic solvent nanofiltration (OSN). However, it is still challenging to produce polyamide hollow fibres for OSN, mainly due to limited solvent resistance of hollow fibre substrates and the difficulty to synthesize polyamide thin film on the surface of hollow fibre substrates. In this study, polyamide-based hollow fibre composite members for low pressure OSN were successfully developed. Solvent resistant polyimide hollow fibre substrates were first prepared through a non-solvent induced phase separation process, followed by chemical cross-linking with hexamethylene diamine. A polyamide thin film layer was then synthesized via interfacial polymerization, by circulating the reactant monomers including polyethyleneimine (PEI), piperazine (PIP) and trimesoyl chloride (TMC) through the hollow fibre lumen. The polyamide thin film with a thickness of ~60 nm was formed on the inner surface of the hollow fibre substrates. The membranes exhibited excellent nanofiltration (NF) performance under 2 bar operating pressure. The permeability of water, acetone and isopropanol was 6.8, 11.6 and 4.5 l m−2 h−1 bar−1, respectively. The membranes also achieved 99.9% and 91.8% rejection to rose bengal (1017 Da) and acid fuchsin (585 Da), respectively, in acetone. Furthermore, a 72-h filtration test was conducted and the membrane showed steady performance throughout the testing period. This study demonstrates the possibility of fabricating polyamide hollow fibre membranes for organic solvent nanofiltration at low pressure, which is desirable for practical applications.

Determination of alkylpyrazines in cocoa samples applying head-space hollow fiber protected-liquid phase microextraction followed by gas chromatography-flame ionization detection

In this research, a novel efficient analytical method for determination of alkylpyrazines (APs) in some food samples was developed based on head-space hollow fiber protected liquid phase microextraction (HS-HFLPME) method. In this method n-octanol was applied as extracting media which was inserted inside lumen of hollow fiber. The developed HFLPME method was used for the preconcentration and extraction of APs including methyl pyrazine, 2,3-dimethyl pyrazine, 2,5-dimethylpyrazine, 2,3,5-trimethyl pyrazine and 2,3,5,6-tetramethyl pyrazine in cocoa and chocolate-milk samples followed by detection applying gas chromatography-flame ionization detector. Important parameters influencing the HS-HFLPME process including extraction time, extraction temperature, salt content and the desorption solvent volume were investigated and optimized applying response surface methodology based on central composite design. Considering the method validation, developed method linear dynamic ranges were 1–200 and 5–500 ng mL−1 for various analytes and the limits of detection were in the range of 0.3 to 1 ng mL−1. The method precision (RSD%) was evaluated by six replicate experiments and RSD% values were obtained in the range of 0.8 to 8.2% for the distilled water (100 ng mL−1). The developed method was used successfully for measurement of AP compounds in cocoa and chocolate-milk samples and the relative recovery percentages (RR%) in the range of 71.7 to 110.5% were obtained.

Investigation of adsorption performance of graphene oxide/polyaniline reinforced hollow fiber membrane for preconcentration of Ivermectin in some environmental samples

Herein, the application of Graphene oxide-polyaniline (GO/PANI) in one of newly hollow fiber based microextraction techniques so called (HF-S/LPME) was investigated successfully. Graphene oxide-polyaniline (GO/PANI) nanocomposite was generated via an amidation reaction in the presence of N, N′-dicyclohexylcarbodiimide (DCC), N-hydroxysuccinimide (NHS) and GO as starting material. The solid sorbent dispersed in dihexyl ether was immersed and injected into the lumen of hollow fiber. The results indicated that GO/PANI had a higher adsorption efficiency for the Ivermectin in comparison with GO and GO-ethylen diamine (GO/EDA). A Taguchi experimental design with an OAD16 (45) matrix was employed to optimize the affecting parameters such as pH, stirring rate, extraction time, salt addition and the volume of donor phase. Under the optimized extraction conditions, the method showed a good linear dynamic range (0.1–5000.0 ppb) with a lower limit of detection (0.03 ppb) and excellent preconcentration factor (PF = 219.88) respectively.

Sensitive determination of seven triazine herbicide in honey, tomato and environmental water samples by hollow fiber based liquid-liquid-liquid microextraction combined with sweeping micellar electrokinetic capillary chromatography

A rapid, simple, and effective method has been developed for the determination of seven triazine herbicides (terbutryn, prometryn, ametryn, prometon, propazine, atrazine, simazine) by coupling off-line hollow fiber liquid liquid liquid microextraction (HF-LLLME) with on-line sweeping micellar electrokinetic chromatography (sweeping-MEKC). In HF-LLLME, seven target triazines in hydrophobic form were extracted from the sample solution into decane impregnated in the pores of the hollow fiber, and then back-extracted into 1 mol L−1 H3PO4 inside the hollow fiber lumen. Then, the pH of acceptor phase was adjusted with 1 μL 1 mol L−1 NaOH for subsequent sweeping-MEKC analysis. In the sweeping-MEKC process, seven triazines were separated in about 16 min with a background electrolyte (BGE) consisting of 92 mmol L−1 phosphate, 40 mmol L−1 SDS and 15% (v/v) 1-propanol (pH = 2.6). The hydrodynamic injection was performed at 50 mbar for 250 s. Under the optimized conditions, the limits of detection were in the range of 0.07–0.69 µg L−1 with enrichment factors of 3100–10000-fold for target triazines, with a dynamic linear range of 0.3/2–100 µg L−1. The developed method exhibited excellent clean-up capability as well as high enrichment factors and was successfully applied to the analysis of target triazines in environmental water, honey and tomato samples.

Hydrodynamic modeling of porous hollow fiber anti-solvent crystallizer for continuous production of drug crystals

This study introduces a Computational Fluid Dynamics (CFD)-based hydrodynamic model for a novel porous hollow fiber-based anti-solvent crystallizer (PHFAC). Here the anti-solvent, water, is introduced from the hollow fiber lumen into the acetone-based feed solution of a drug flowing on the shell side where crystals of the drug Griseofulvin are formed and swept away. Such a device is very useful for achieving continuous anti-solvent crystallization with significant crystal size control. It is necessary to predict the hydrodynamics and other mixing characteristics of the PHFAC device to facilitate optimization and prediction of their behavior. In this study, a 3D physical model for a PHFAC device was first constructed using the software GAMBIT. After meshing and optimization, a 3D computational simulation-based modeling was conducted by the CFD software FLUENT for understanding the hydrodynamics and the mixing characteristics of a miscible aqueous-organic system in the PHFAC module without any drug being present. Different combinations of characteristic parameters e.g., inlet flow rates of the shell side and tube side and numbers of hollow fiber membranes, were investigated to optimize the conditions from the perspective of shell-side mixing of the two fluids. The CFD-based study revealed an optimized flow rate combination by examining the interior mixing pattern in the module shell-side under different flow conditions. The optimized flow rate ratio was found numerically to be the same for two different sized modules with one having twice the number of hollow fiber membranes than the other. The CFD simulation results of mixing conditions suggest that the optimized flow rate combinations for shell-side mixing are also coincident with previously obtained experimental results of smaller crystal size of the drug, Griseofulvin and the morphology of the precipitated drug crystals. However, the absence of any crystal formation dynamics in the CFD model suggests the need for a more comprehensive model which can predict the crystal size distribution (CSD).

Surfactant-assisted electromembrane extraction combined with cyclodextrin-modified capillary electrophoresis for the separation and quantification of Tranylcypromine enantiomers in biological samples.

Surfactant-assisted electromembrane extraction coupled with cyclodextrin-modified capillary electrophoresis was developed for the separation and determination of Tranylcypromine enantiomers in biological samples. This combination would provide a new strategy for selective and sensitive determination of target analytes. The addition of surfactant in the donor solution improved the analyte transport into the lumen of hollow fiber that resulted in an enhancement in the analytes migration into acceptor solution. Optimization of the variables, affecting proposed method, was carried out and best results were achieved with a 175V potential as driving force of the electromembrane extraction, 2-nitrophenyloctylether as the supported liquid membrane, donor solution containing 0.2mM Triton X-100 with pH 3 and 0.1M HCl for acceptor solution. Then, the extract was analyzed using cyclodextrin-modified capillary electrophoresis method for separation of Tranylcypromine enantiomers. The best results were obtained with a phosphate running buffer (100mM, pH 2.0) containing 7%w/v hydroxypropyl-α-cyclodextrin. Under the optimum conditions, a low limit of detection (3.03ng/mL), good linearity (R2 >0.9953), and relative standard deviations below 4.0% (n=5) were obtained. Finally, this procedure was applied to determine the concentration of Tranylcypromine enantiomers in urine samples with satisfactory results.

A review of hollow fibers in application-based learning: from textiles to medical

Hollow fibers are highly valued in the textile industry. Their physical properties and other superior characteristics make them a crucial material for innovations in textiles in the medical field, where they could provide solutions to therapeutic challenges. The inner lumen of hollow fibers has potential for use in medical and healthcare devices. For example, hollow fibers could be used to deliver drugs to a target site, enhance blood purification, promote cell cultures, and enable drug screening. The use of hollow fibers could have beneficial effects for medical and therapeutic performance; a market for hollow fiber-based medical clothing is anticipated for promotion of an efficient, long-term, and convenient commercial medical therapy. This review discusses the development of medical textiles and describes the use of hollow fibers in different medical contexts, as well as the benefits of their use and their potential industrial applications in medical textiles and clothing.