scholarly journals Fabrication of Electrospun Membranes based on Poly(caprolactone) (PCL) and PCL/Chitosan Layer by Layer for Tissue Engineering

2017 ◽  
Vol 17 (1) ◽  
Author(s):  
Choi Yee Foong ◽  
Naznin Sultana
Keyword(s):  
Tissue Engineering ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Water Uptake ◽  
Solution Concentration ◽  
Layered Composite ◽  
Layer By Layer ◽  
Electrospun Membrane ◽  
Water Contact ◽  
Electrospun Membranes

Recently, in the field of tissue engineering, fabrication of three-dimensional (3D) electrospun scaffold or membrane is much emphasized. In this study, layered composite scaffolds or membranes were fabricated using two biodegradable polymers, polycaprolactone (PCL) and Chitosan layer-by-layer with multilayer electrospinning method. Characterizations of membranes were done using several techniques. Electrospun composite membrane’s surface morphology was examined using a Scanning Electron Microscopy (SEM) and the wettability of the material’s surface was determined using water contact angle measuring measurement (WCA). Water uptake properties of electrospun membrane were also determined. Using optimized solution concentration and electrospinning processing parameters, the composite PCL/Chitosan and PCL layer-by-layer were successfully fabricated. It was observed from SEM that the composite electrospun membranes produced consisted microfibers and nanofibers within single scaffold. The water contact angle for the double-layered composite electrospun membranes was lower than the pure PCL. The double-layered composite membrane also had higher water uptake properties compared to pure PCL scaffold.

scholarly journals HYDROPHOBIC IMPREGNATION OF GEOPOLYMER COMPOSITE BY ETHOXYSILANES

2018 ◽  
Vol 58 (3) ◽  
pp. 184
Author(s):  
Zdeněk Mašek ◽  
Linda Diblikova
Keyword(s):  
Contact Angle ◽  
Elevated Temperature ◽  
Water Contact Angle ◽  
Water Uptake ◽  
Outer Surface ◽  
Alkyl Group ◽  
Sio2 Nanoparticles ◽  
Water Contact ◽  
Composite Surface ◽  
Geopolymer Composites

A geopolymer composite was impregnated by incorporating the hydrophobic alkyl group on the outer surface and in the inner structure of the geopolymer. Ethoxysilanes 1H,1H,2H,2H perfluoroctyltriethoxysilane and hexadecyltrimethoxysilane were used as the source of hydrophobic groups. Three types of solutions based on the ethoxysilanes were prepared according to adapted procedures. The modification of the geopolymer composites was done by their immersion into the hydrophobic solutions followed by drying at a laboratory or elevated temperature. The effectivity of the procedure was evaluated by measuring the water contact angle on the surface of the modified composite and by measuring the water uptake and stiffness of the composite. The results confirmed that the silanes hydrolyzed in sol containing SiO2 nanoparticles have a higher hydrophobization effect than solutions of simply hydrolyzed silanes. The resulting impregnation procedure led to the change of the geopolymer composite surface from hydrophilic to hydrophobic.

Aligned Electrospun Polyvinyl Pyrrolidone/Poly ε-Caprolactone Blend Nanofiber Mats for Tissue Engineering

2016 ◽  
Vol 15 (01n02) ◽  
pp. 1650005 ◽  
Author(s):  
Natthan Charernsriwilaiwat ◽  
Theerasak Rojanarata ◽  
Tanasait Ngawhirunpat ◽  
Praneet Opanasopit
Keyword(s):  
Tissue Engineering ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Human Fibroblasts ◽  
Polyvinyl Pyrrolidone ◽  
Cell Alignment ◽  
Tissue Engineering Scaffolds ◽  
Electrospinning Technique ◽  
Water Contact ◽  
Nanofiber Mats

Electrospun nanofibrous materials are widely used in medical applications such as tissue engineering scaffolds, wound dressing material and drug delivery carriers. For tissue engineering scaffolds, the structure of the nanofiber is similar to extracellular matrix (ECM) which promotes the cell growth and proliferation. In the present study, the aligned nanofiber mats of polyvinyl pyrrolidone (PVP) blended poly [Formula: see text]-caprolactone (PCL) was successfully generated using electrospinning technique. The morphology of PVP/PCL nanofiber mats were characterized by scanning electron microspore (SEM). The chemical and crystalline structure of PVP/PCL nanofiber mats were analyzed using Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffactometer (PXRD). The water contact angle of mats was investigated. Cell culture studies using normal human fibroblasts (NHF) were performed to assess cell morphology, cell alignment and cell proliferation. The results indicated that the fiber were in nanometer range. The PVP/PCL was well dispersed in nanofiber mats and was in amorphous form. The water contact angle of PVP/PCL nanofiber mats was lower than PCL nanofiber mats. The PVP/PCL nanofiber mats exhibited good biocompatibility with NHF cells. In summary, the PVP/PCL nanofiber mats had potential to be used in tissue engineering and regenerative medicine.

Formation and characterization of superhydrophobic and alcohol-repellent nonwovens via electrohydrodynamic atomization (electrospraying)

2016 ◽  
Vol 47 (1) ◽  
pp. 125-146 ◽  
Author(s):  
Mehmet Dasdemir ◽  
Hatice Ibili
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Maximum Level ◽  
Solution Concentration ◽  
Water Mixture ◽  
Water Contact ◽  
Nonwoven Fabrics ◽  
Alcohol Water ◽  
Electrohydrodynamic Atomization ◽  
Coated Fabrics

This study focuses on the development of superhydrophobic and alcohol-repellent medical nonwoven fabrics via electrohydrodynamic atomization (electrospraying). It also compares the effectiveness of electrospraying with conventional pad-dry-cure finishing application. A commercial fluorochemical finishing agent was used to prepare fluorochemical solutions at varying concentrations (0.9–9 wt%). Electrospraying characteristics of these solutions were determined with characterizing their solution properties such as viscosity, conductivity and surface tension. After the successful applications of fluorochemical solutions on nonwoven fabrics via padding and electrospraying, wet pick-up ratios and weight gains of these fabrics were calculated. Also, water and alcohol repellencies of the coated fabrics were characterized with water contact angle and alcohol contact angle measurements. According to our findings, electrospraying application yielded less chemical consumption and higher water contact angle and alcohol contact angle results than padding. Increasing solution concentration and application time for electrospraying enhanced water contact angle values, which reached a maximum level (up to 156°) and afterwards remained almost constant depending on these variables. Thus, their limits to achieve superhydrophobic surfaces were able to be determined. Electrosprayed nonwovens were also shown to be alcohol-repellent against alcohol/water mixture of 70/30 (v/v%) whereas that was 30/70 (v/v%) for padded nonwovens. The investigation of the electrosprayed surfaces revealed a very less coating on the uppermost side of surface fibres which mostly led to the enhanced water and alcohol repellencies. One of the other important outcomes of this study is that there was no significant change on the comfort properties of nonwoven fabrics after the electrospraying application.

scholarly journals Preparation of Water Repellent Layer on Glass Using Hydrophobic Compound Modified Rice Hull Ash Silica

2018 ◽  
Vol 18 (4) ◽  
pp. 587 ◽  
Author(s):  
Alfa Akustia Widati ◽  
Nuryono Nuryono ◽  
Dessy Puspa Aryanti ◽  
Madjid Arie Wibowo ◽  
Eko Sri Kunarti ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Sio2 Layer ◽  
Rice Hull ◽  
Water Repellent ◽  
Layer By Layer ◽  
Ambient Conditions ◽  
Rice Hull Ash ◽  
Water Contact ◽  
Layer Number

In this study water repellent layered glass has been prepared by coating silica (SiO2) combined with a hydrophobic silane compound. SiO2 was extracted from rice hull ash and two silane compounds, namely hexadecyltrimethoxysilane (HDTMS) and trimethylchlorosilane (TMCS) were used. Coating was performed through two deposition techniques, i.e. one step (mono-layer) and layer by layer (LBL, multi-layer). The effect of silane to SiO2 mole ratio, silane type and layer number on the glass characters was evaluated. Characterization included hydrophobicity, transparency, surface roughness and stability of coating. Results showed that increasing the mole ratio of silane to SiO2 and the layer number increased the hydrophobicity of the glass surface. The optimum mole ratio was 5:1 and the significant increase of contact angle occurred at lower mole ratio, but the stability tends to be increased at higher mole ratio. For HDTMS-SiO2 layer, the technique of LBL technique produced a coating with higher hydrophobicity and transparency than single-stage one. The LBL technique produced the highest water contact angle of 103.7° with transmittance of 96%, while for TMCS-SiO2 layer the one stage technique produced hydrophobic layer with higher water contact angle of 108.0° and transparency about 94.52%. The prepared hydrophobic glasses were relatively stable in polar and non-polar solvents, but unstable to ambient conditions.

scholarly journals Modeling Experimental Parameters for the Fabrication of Multifunctional Surfaces Composed of Electrospun PCL/ZnO-NPs Nanofibers

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4312
Author(s):  
Pedro J. Rivero ◽  
Juan P. Fuertes ◽  
Adrián Vicente ◽  
Álvaro Mata ◽  
José F. Palacio ◽  
...  
Keyword(s):  
Contact Angle ◽  
Corrosion Resistance ◽  
Surface Morphology ◽  
Water Contact Angle ◽  
Solution Concentration ◽  
Electrospun Fibers ◽  
Operational Parameters ◽  
Zno Nps ◽  
Electrospinning Technique ◽  
Water Contact

In this work, a one-step electrospinning technique has been implemented for the design and development of functional surfaces with a desired morphology in terms of wettability and corrosion resistance by using polycaprolactone (PCL) and zinc oxide nanoparticles (ZnO NPs). The surface morphology has been characterized by confocal microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM) and water contact angle (WCA), whereas the corrosion resistance has been evaluated by Tafel polarization curves. Strict control over the input operational parameters (applied voltage, feeding rate, distance tip to collector), PCL solution concentration and amount of ZnO NPs have been analyzed in depth by showing their key role in the final surface properties. With this goal in mind, a design of experiment (DoE) has been performed in order to evaluate the optimal coating morphology in terms of fiber diameter, surface roughness (Ra), water contact angle (WCA) and corrosion rate. It has been demonstrated that the solution concentration has a significant effect on the resultant electrospun structure obtained on the collector with the formation of beaded fibers with a higher WCA value in comparison with uniform bead-free fibers (dry polymer deposition or fiber-merging aspect). In addition, the presence of ZnO NPs distributed within the electrospun fibers also plays a key role in corrosion resistance, although it also leads to a decrease in the WCA. Finally, this is the first time that an exhaustive analysis by using DoE has been evaluated for PCL/ZnO electrospun fibers with the aim to optimize the surface morphology with the better performance in terms of corrosion resistance and wettability.

scholarly journals Design of SiO2/TiO2 that Synergistically Increases The Hydrophobicity of Methyltrimethoxysilane Coated Glass

2019 ◽  
Vol 17 (1) ◽  
pp. 798-805 ◽  
Author(s):  
Alfa Akustia Widati ◽  
Nuryono Nuryono ◽  
Indriana Kartini
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Research Work ◽  
Dip Coating ◽  
Layer By Layer ◽  
Titanium Tetraisopropoxide ◽  
Water Contact ◽  
Nanoscale Structures ◽  
Coated Glass

AbstractThis research work presents the design of a mixture of SiO2/TiO2 that increases the surface roughness and hydrophobicity of methyltrimethoxysilane (MTMS) coated glass. The deposition of SiO2, TiO2, and MTMS were conducted using a layer by layer dip coating technique. The SiO2/TiO2 coating was derived from complete hydrolysis of tetraethylorthsilicate and titanium tetraisopropoxide. In order to evaluate and compare the performance of SiO2/TiO2/MTMS coated glass, the SiO2/SiO2/MTMS and TiO2/TiO2/MTMS were also fabricated. SiO2/TiO2/MTMS samples displayed the highest water contact angle. The topography of surfaces showed that SiO2/TiO2/MTMS exposed higher surface roughness with micro-nanoscale structures. The sequence of SiO2 and TiO2 influenced the water contact angle and the stability of the coatings. SiO2/TiO2/MTMS produced higher contact angle and stability than TiO2/SiO2/MTMS.

Preparation and characterization of fouling-resistant composite membranes based on layer-by-layer self-assembly technique

2011 ◽  
Vol 64 (11) ◽  
pp. 2223-2229 ◽  
Author(s):  
J. L. Duan ◽  
H. M. Zhang ◽  
C. C. Wang ◽  
H. Y. Li ◽  
F. L. Yang
Keyword(s):  
Contact Angle ◽  
Protein Adsorption ◽  
Water Contact Angle ◽  
Morphological Changes ◽  
Membrane Surface ◽  
Composite Membranes ◽  
Ammonium Bromide ◽  
Layer By Layer ◽  
Water Contact ◽  
Antifouling Property

This paper introduces a versatile approach for surface modification of 621-terylene filtration fabric (FF) self-assembled by a dynamic layer-by-layer technique. The hexadecyl trimethyl ammonium bromide (HTAB) and cross-linked polyvinyl alcohol microspheres (PVA-MS) were alternatively deposited on support membrane under a pressure of 0.01 MPa to modify FF. Morphological changes and hydrophilicity of the modified FF were characterized in detail by scanning electron micrograph and water contact angle measurements. Results revealed that PVA-MS could be adsorbed mainly on the surface of FF and water contact angle decreased with the increase of HTAB/PVA-MS bilayer numbers indicating an enhanced hydrophilicity for the modified FF. Backwash experiments of the modified FF exhibited much higher stability of PVA-MS. Protein adsorption experiments were conducted to evaluate the antifouling property of the modified FF. Results indicated that protein adsorption of the membrane surface could be obviously improved by modification, which exhibited superior antifouling property of the modified FF.

Long-Term Stable Metal Organic Framework (MOF) Based Mixed Matrix Membranes for Ultrafiltration

2020 ◽  
Author(s):  
Muayad Al-shaeli ◽  
Stefan J. D. Smith ◽  
Shanxue Jiang ◽  
Huanting Wang ◽  
Kaisong Zhang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Mixed Matrix Membranes ◽  
Recovery Ratio ◽  
Mixed Matrix ◽  
Water Contact ◽  
Membrane Performance ◽  
Metal Organic ◽  
Matrix Membranes

<p>In this study, novel <a>mixed matrix polyethersulfone (PES) membranes</a> were synthesized by using two different kinds of metal organic frameworks (MOFs), namely UiO-66 and UiO-66-NH<sub>2</sub>. The composite membranes were characterised by SEM, EDX, FTIR, PXRD, water contact angle, porosity, pore size, etc. Membrane performance was investigated by water permeation flux, flux recovery ratio, fouling resistance and anti-fouling performance. The stability test was also conducted for the prepared mixed matrix membranes. A higher reduction in the water contact angle was observed after adding both MOFs to the PES and sulfonated PES membranes compared to pristine PES membranes. An enhancement in membrane performance was observed by embedding the MOF into PES membrane matrix, which may be attributed to the super-hydrophilic porous structure of UiO-66-NH<sub>2</sub> nanoparticles and hydrophilic structure of UiO-66 nanoparticles that could accelerate the exchange rate between solvent and non-solvent during the phase inversion process. By adding the MOFs into PES matrix, the flux recovery ratio was increased greatly (more than 99% for most mixed matrix membranes). The mixed matrix membranes showed higher resistance to protein adsorption compared to pristine PES membranes. After immersing the membranes in water for 3 months, 6 months and 12 months, both MOFs were stable and retained their structure. This study indicates that UiO-66 and UiO-66-NH<sub>2</sub> are great candidates for designing long-term stable mixed matrix membranes with higher anti-fouling performance.</p>

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