scholarly journals Water uptake of various electrospun nonwovens

2020 ◽  
Vol 6 (3) ◽  
pp. 155-158
Author(s):  
Katharina Wulf ◽  
Volkmar Senz ◽  
Thomas Eickner ◽  
Sabine Illner
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Water Absorption ◽  
Water Uptake ◽  
Biomedical Applications ◽  
High Surface ◽  
Volume Ratio ◽  
Polymer Composition ◽  
Water Wetting ◽  
Morphology Changes

AbstractIn recent years, nanofiber based materials have emerged as especially interesting for several biomedical applications, regarding their high surface to volume ratio. Due to the superficial nano- and microstructuring and the different wettability compared to nonstructured surfaces, the water absorption is an important parameter with respect to the degradation stability, thermomechanic properties and drug release properties, depending on the type of polymer [1]. In this investigation, the water absorption of different non- and plasma modified biostable nanofiber nonwovens based on polyurethane, polyester and polyamide were analysed and compared. Also, the water absorption by specified water wetting, the contact angle and morphology changes were examined. The results show that the water uptake is highly dependent on the surface modification and the polymer composition itself and can therefore be partially changed.

Analysis on surface modification of orthodontic power chain by nanoimprinting process

2014 ◽  
Vol 34 (3) ◽  
pp. 209-217
Author(s):  
Hsing-Chung Cheng ◽  
Wan-Tin Lin ◽  
Yung-Kang Shen ◽  
Yen-Hsiang Wang
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Surface Treatment ◽  
Water Absorption ◽  
Process Parameters ◽  
Pure Aluminum ◽  
Polymer Materials ◽  
Hydrophobic Properties ◽  
Water Absorbance

Abstract The traditional orthodontic power chain, usually made of polymer materials, exists some drawbacks, such as the reduction of elasticity due to swell after absorbing water and surface discoloration resulting from the patient’s diet, food, or beverage colors leading to poor appearance. The main purpose of this study was to develop surface modification on orthodontic power chain and to realize the properties change for improvement of its shortcomings. In this study, a template was produced by pure aluminum piece with anodized production (concave) through the nanoimprinting process fabricating nanostructures (convex) on the surface of power chain, resulting in surface modification of power chain. The different nanoimprinting process parameters (e.g., imprinting temperature, imprinting pressure, imprinting time, and demolding temperature) were used to produce nanostructures on the surface of power chain. The results of this study show that the contact angle of the power chain became larger after nanoimprinting surface treatment. The hydrophilic properties of power chain have been turned into hydrophobic properties. Unmodified power chain before water absorption is about 4%, while a modified water absorbance is about 2%–4%.

scholarly journals Development of Superhydrophobic Cotton Fabric Using Zinc Oxide Nanoflower/Polydimethylsiloxane (PDMS) Nanocomposite Coatings

2021 ◽  
Author(s):  
Sorna Gowri Vijaya Kumar ◽  
◽  
Priyanka Prabhakar ◽  
Raj Kumar Sen ◽  
Neha Uppal ◽  
...  
Keyword(s):  
Contact Angle ◽  
Zinc Oxide ◽  
Cotton Fabric ◽  
Sessile Drop ◽  
High Surface ◽  
Average Particle Size ◽  
Volume Ratio ◽  
Average Particle ◽  
Water Contact ◽  
Scherrer Formula

Nanoflower is anticipated to become a very smart material due to its unique properties such as high surface to volume ratio. A hydrothermal method was used in this study to prepare the zinc oxide (ZnO) nanoflower and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The average particle size of the ZnO nanoflower was calculated as 21nm according to the Debye-Scherrer formula. The SEM result gives the surface morphological information of the ZnO nanoflower, which confirms the formation of the ZnO nanoflower. The ZnO nanoflower was dispersed in PDMS and coated onto cotton fabric to get the superhydrophobic fabric. The hydrophobicity was determined by measuring the water contact angle by the Sessile drop method and it was observed that coated fabrics have the highest contact angle, 140⁰ at 0.5% ZnO nanoflower concentration. The present study offers a method of fabrication of superhydrophobic cotton textile using ZnO nanoflower/PDMS polymer nanocomposites.

scholarly journals Green fabrication of Co and Co3O4 nanoparticles and their biomedical applications: A review

2021 ◽  
Vol 16 (1) ◽  
pp. 14-30
Author(s):  
Abdul Waris ◽  
Misbahud Din ◽  
Asmat Ali ◽  
Shakeeb Afridi ◽  
Abdul Baset ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Environmental Remediation ◽  
Biomedical Applications ◽  
High Surface ◽  
Volume Ratio ◽  
Lithium Ion ◽  
High Energy ◽  
Co3o4 Nanoparticles ◽  
Simple Method ◽  
Cobalt Oxide Nanoparticles

Abstract Nanotechnology is the fabrication, characterization, and potential application of various materials at the nanoscale. Over the past few decades, nanomaterials have attracted researchers from different fields because of their high surface-to-volume ratio and other unique and remarkable properties. Cobalt and cobalt oxide nanoparticles (NPs) have various biomedical applications because of their distinctive antioxidant, antimicrobial, antifungal, anticancer, larvicidal, antileishmanial, anticholinergic, wound healing, and antidiabetic properties. In addition to biomedical applications, cobalt and cobalt oxide NPs have been widely used in lithium-ion batteries, pigments and dyes, electronic thin film, capacitors, gas sensors, heterogeneous catalysis, and for environmental remediation purposes. Different chemical and physical approaches have been used to synthesize cobalt and cobalt oxide NPs; however, these methods could be associated with eco-toxicity, cost-effectiveness, high energy, and time consumption. Recently, an eco-friendly, safe, easy, and simple method has been developed by researchers, which uses biotic resources such as plant extract, microorganisms, algae, and other biomolecules such as starch and gelatin. Such biogenic cobalt and cobalt oxide NPs offer more advantages over other physicochemically synthesized methods. In this review, we have summarized the recent literature for the understanding of green synthesis of cobalt and cobalt oxide NPs, their characterization, and various biomedical applications.

scholarly journals Size Also Matters in Biodegradable Composite Microfiber Reinforced by Chitosan Nanofibers

2014 ◽  
Vol 1621 ◽  
pp. 59-69
Author(s):  
Elisabete D. Pinho ◽  
Albino Martins ◽  
José V. Araújo ◽  
Rui L. Reis ◽  
Nuno M. Neves
Keyword(s):  
Biomedical Applications ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Electrospun Nanofibers ◽  
Butylene Succinate ◽  
Biodegradable Composite ◽  
Biological Performance ◽  
Different Diameters ◽  
Kinetics Of

ABSTRACTPioneer works on nanocomposites were focused in carbon nanofibers or nanotubes dispersed in epoxy matrix, a viscous liquid facilitating the compounding stage. The interest in developing new composites aimed for biomedical applications led us to design new nanocomposites based in biodegradable polymers with demonstrated biological performance.We report herein the development of micro-nano composites by extruding poly(butylene succinate) (PBS) microfibers with two different diameters, 200 and 500 µm, reinforced with electrospun chitosan nanofibers. Analysis of the microfibers showed high levels of alignment of the reinforcing phase and excellent distribution of the nanofibers in the composite. Its geometry facilitates the development of orthotropy, maximizing the reinforcement in the axial fiber main axis.The biodegradable microfiber composites show an outstanding improvement of mechanical properties and of the kinetics of biodegradation, with very small fractions (0.05 and 0.1 wt.%) of electrospun chitosan nanofibers reinforcement. The high surface area-to-volume ratio of electrospun nanofibers combined with the increased water uptake capability of chitosan justify the accelerated kinetics of biodegradation of the composite as compared with the unfilled synthetic polymer.

scholarly journals Immobilization of Protein A on Monodisperse Magnetic Nanoparticles for Biomedical Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Bui Trung Thanh ◽  
Nguyen Van Sau ◽  
Heongkyu Ju ◽  
Mohammed J. K. Bashir ◽  
Hieng Kiat Jun ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Magnetic Nanoparticles ◽  
Biomedical Applications ◽  
Point Of Care ◽  
High Surface ◽  
Protein A ◽  
Volume Ratio ◽  
Controlled Drug Release ◽  
Disease Diagnosis

We presented synthesis and physical characterization of iron oxide magnetic nanoparticles (Fe3O4) for biomedical applications in the size range of 10-30 nm. Magnetic nanoparticles were synthesized by the coprecipitation method, and the particles’ size was controlled by two different injection methods of sodium hydroxide (NaOH). The synthesized magnetic nanoparticles were then modified by using series of linkers including tetraethyl orthosilicate (TEOS), 3-aminopropyltriethoxysilane (APTES), and glutaraldehyde (GA) to generate the structure of Fe3O4/SiO2/NH2/CHO, which can be used for immobilization of protein A. Additionally, we used transmission electron microscopy (TEM), X-ray powder diffraction (XRD), vibrating-sample magnetometry (VSM), and Fourier-transform infrared spectroscopy (FTIR), for characterization of properties and structure of the nanoparticles. An immobilization of protein A on magnetic nanoparticles was studied with a UV-Vis spectrum (UV-Vis) and fluorescence electron microscopy and Bradford method. Results showed that an XRD spectrum with a peak at (311) corresponded to the standard peak of magnetic nanoparticles. In addition, the magnetic nanoparticles with d≥30 nm have higher saturation magnetizations in comparison with the smaller ones with d≤10 nm. However, the smaller magnetic nanoparticles offered higher efficiency for binding of protein A, due to the high surface/volume ratio. These particles with functional groups on their surface are promising candidates for biomedical applications, e.g., drug delivery, controlled drug release, or disease diagnosis in point-of-care test.

scholarly journals Surface Treatment on Physical Properties and Biocompatibility of Orthodontic Power Chains

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
H. C. Cheng ◽  
M. S. Chen ◽  
B. Y. Peng ◽  
W. T. Lin ◽  
Y. K. Shen ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Physical Properties ◽  
Surface Treatment ◽  
Water Absorption ◽  
Absorption Rate ◽  
Pure Aluminum ◽  
Polymer Materials ◽  
Water Absorption Rate ◽  
Anodization Process

The conventional orthodontic power chain, often composed of polymer materials, has drawbacks such as a reduction of elasticity owing to water absorption as well as surface discoloration and staining resulting from food or beverages consumed by the patient. The goal of this study was to develop a surface treatment (nanoimprinting) for orthodontic power chains and to alleviate their shortcomings. A concave template (anodic alumina) was manufactured by anodization process using pure aluminum substrate by employing the nanoimprinting process. Convex nanopillars were fabricated on the surface of orthodontic power chains, resulting in surface treatment. Distinct parameters of the nanoimprinting process (e.g., imprinting temperature, imprinting pressure, imprinting time, and demolding temperature) were used to fabricate nanopillars on the surface of orthodontic power chains. The results of this study showed that the contact angle of the power chains became larger after surface treatment. In addition, the power chains changed from hydrophilic to hydrophobic. The power chain before surface treatment without water absorption had a water absorption rate of approximately 4%, whereas a modified chain had a water absorption rate of approximately 2%–4%. Furthermore, the color adhesion of the orthodontic power chains after surface modification was less than that before surface modification.

scholarly journals Surface modification of PMMA polymer and its composites with PC61BM fullerene derivative using an atmospheric pressure microwave argon plasma sheet

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrzej Sikora ◽  
Dariusz Czylkowski ◽  
Bartosz Hrycak ◽  
Magdalena Moczała-Dusanowska ◽  
Marcin Łapiński ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Chemical Composition ◽  
Water Contact Angle ◽  
Plasma Sheet ◽  
Atmospheric Pressure ◽  
Argon Plasma ◽  
Fullerene Derivative ◽  
Water Contact ◽  
Pmma Polymer

AbstractThis paper presents the results of experimental investigations of the plasma surface modification of a poly(methyl methacrylate) (PMMA) polymer and PMMA composites with a [6,6]-phenyl-C61-butyric acid methyl ester fullerene derivative (PC61BM). An atmospheric pressure microwave (2.45 GHz) argon plasma sheet was used. The experimental parameters were: an argon (Ar) flow rate (up to 20 NL/min), microwave power (up to 530 W), number of plasma scans (up to 3) and, the kind of treated material. In order to assess the plasma effect, the possible changes in the wettability, roughness, chemical composition, and mechanical properties of the plasma-treated samples’ surfaces were evaluated by water contact angle goniometry (WCA), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The best result concerning the water contact angle reduction was from 83° to 29.7° for the PMMA material. The ageing studies of the PMMA plasma-modified surface showed long term (100 h) improved wettability. As a result of plasma treating, changes in the samples surface roughness parameters were observed, however their dependence on the number of plasma scans is irregular. The ATR-FTIR spectra of the PMMA plasma-treated surfaces showed only slight changes in comparison with the spectra of an untreated sample. The more significant differences were demonstrated by XPS measurements indicating the surface chemical composition changes after plasma treatment and revealing the oxygen to carbon ratio increase from 0.1 to 0.4.

scholarly journals Enhancement of mechanical, thermal and water uptake performance of TPU/jute fiber green composites via chemical treatments on fiber surface

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 133-143 ◽  
Author(s):  
Tuffaha Fathe Salem ◽  
Seha Tirkes ◽  
Alinda Oyku Akar ◽  
Umit Tayfun
Keyword(s):  
Water Absorption ◽  
Water Uptake ◽  
Mechanical Test ◽  
Fiber Surface ◽  
Melt Flow Index ◽  
Jute Fiber ◽  
Morphological Properties ◽  
Flow Index ◽  
Melt Flow ◽  
Treatment Type

AbstractChopped jute fiber (JF) surfaces were modified using alkaline, silane and eco-grade epoxy resin. Surface characteristics of jute fibers were confirmed by FTIR and EDX analyses. JF filled polyurethane elastomer (TPU) composites were prepared via extrusion process. The effect of surface modifications of JF on mechanical, thermo-mechanical, melt-flow, water uptake and morphological properties of TPU-based eco-composites were investigated by tensile and hardness tests, dynamic mechanical analysis (DMA), melt flow index (MFI) test, water absorption measurements and scanning electron microscopy (SEM) techniques, respectively. Mechanical test results showed that silane and epoxy treated JF additions led to increase in tensile strength, modulus and hardness of TPU. Glass transition temperature (Tg) of TPU rose up to higher values after JF inclusions regardless of treatment type. Si-JF filled TPU exhibited the lowest water absorption among composites. Surface treated JFs displayed homogeneous dispersion into TPU and their surface were covered by TPU according to SEM micro-photographs.

scholarly journals Effect of Water Ingress on the Mechanical and Chemical Properties of Polybutylene Terephthalate Reinforced with Glass Fibers

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1261
Author(s):  
Catarina S. P. Borges ◽  
Alireza Akhavan-Safar ◽  
Eduardo A. S. Marques ◽  
Ricardo J. C. Carbas ◽  
Christoph Ueffing ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Water Uptake ◽  
Significant Influence ◽  
Water Immersion ◽  
Water Diffusion ◽  
Polybutylene Terephthalate ◽  
Chemical Changes ◽  
Water Ingress ◽  
Effect Of Water

Short fiber reinforced polymers are widely used in the construction of electronic housings, where they are often exposed to harsh environmental conditions. The main purpose of this work is the in-depth study and characterization of the water uptake behavior of PBT-GF30 (polybutylene terephthalate with 30% of short glass fiber)as well as its consequent effect on the mechanical properties of the material. Further analysis was conducted to determine at which temperature range PBT-GF30 starts experiencing chemical changes. The influence of testing procedures and conditions on the evaluation of these effects was analyzed, also drawing comparisons with previous studies. The water absorption behavior was studied through gravimetric tests at 35, 70, and 130 °C. Fiber-free PBT was also studied at 35 °C for comparison purposes. The effect of water and temperature on the mechanical properties was analyzed through bulk tensile tests. The material was tested for the three temperatures in the as-supplied state (without drying or aging). Afterwards, PBT-GF30 was tested at room temperature following water immersion at the three temperatures. Chemical changes in the material were also analyzed through Fourier-transform infrared spectroscopy (FTIR). It was concluded that the water diffusion behavior is Fickian and that PBT absorbs more water than PBT-GF30 but at a slightly higher rate. However, temperature was found to have a more significant influence on the rate of water diffusion of PBT-GF30 than fiber content did. Temperature has a significant influence on the mechanical properties of the material. Humidity contributes to a slight drop in stiffness and strength, not showing a clear dependence on water uptake. This decrease in mechanical properties occurs due to the relaxation of the polymeric chain promoted by water ingress. Between 80 and 85 °C, after water immersion, the FTIR profile of the material changes, which suggests chemical changes in the PBT. The water absorption was simulated through heat transfer analogy with good results. From the developed numerical simulation, the minimum plate size to maintain the water ingress unidirectional was 30 mm, which was validated experimentally.

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