scholarly journals Hot-melt Adhesive Bonding of Polyurethane/Fluorinated Polyurethane/Alkylsilane-Functionalized Graphene Nanofibrous Fabrics with Enhanced Waterproofness, Breathability, and Mechanical Properties

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 836 ◽  
Author(s):  
Chunhui Liu ◽  
Xi Liao ◽  
Weili Shao ◽  
Fan Liu ◽  
Bin Ding ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Adhesive Bonding ◽  
Mechanical Performance ◽  
Transmission Rate ◽  
High Porosity ◽  
Functionalized Graphene ◽  
Hot Press ◽  
Treatment Technology ◽  
Fluorinated Polyurethane ◽  
Small Pore

Waterproof-breathable (WB) materials with outstanding waterproofness, breathability, and mechanical performance are critical in diverse consumer applications. Electrospun nanofibrous membranes with thin fiber diameters, small pore sizes, and high porosity have attracted significant attention in the WB fabric field. Hot-press treatment technology can induce the formation of inter-fiber fusion structures and hence improve the waterproofness and mechanical performance. By combining electrospinning and hot-press treatment technology, polyurethane/fluorinated polyurethane/thermoplastic polyurethane/alkylsilane-functionalized graphene (PU/FPU/TPU/FG) nanofiber WB fabric was fabricated. Subsequently, the morphologies, porous structure, hydrostatic pressure, water vapor transmission rate (WVTR), and stress–strain behavior of the nanofiber WB fabric were systematically investigated. The introduction of the hydrophobic FG sheet structure and the formation of the inter-fiber fusion structure greatly improved not only the waterproofness but also the mechanical performance of the nanofiber WB fabric. The optimized PU/FPU/TPU-50/FG-1.5 WB fabric exhibited an excellent comprehensive performance: a high hydrostatic pressure of 80.4 kPa, a modest WVTR of 7.6 kg m−2 d−1, and a robust tensile stress of 127.59 MPa, which could be used to achieve various applications. This work not only highlights the preparation of materials, but also provides a high-performance nanofiber WB fabric with huge potential application prospects in various fields.

scholarly journals Drug Delivery Applications of Core-Sheath Nanofibers Prepared by Coaxial Electrospinning: A Review

Pharmaceutics ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 305 ◽  
Author(s):  
Bishweshwar Pant ◽  
Mira Park ◽  
Soo-Jin Park
Keyword(s):  
Drug Delivery ◽  
Electrospun Nanofibers ◽  
Coaxial Electrospinning ◽  
Burst Release ◽  
High Porosity ◽  
Nanofiber Membrane ◽  
Initial Burst ◽  
Initial Burst Release ◽  
Small Pore ◽  
Drug Delivery Applications

Electrospinning has emerged as one of the potential techniques for producing nanofibers. The use of electrospun nanofibers in drug delivery has increased rapidly over recent years due to their valuable properties, which include a large surface area, high porosity, small pore size, superior mechanical properties, and ease of surface modification. A drug loaded nanofiber membrane can be prepared via electrospinning using a model drug and polymer solution; however, the release of the drug from the nanofiber membrane in a safe and controlled way is challenging as a result of the initial burst release. Employing a core-sheath design provides a promising solution for controlling the initial burst release. Numerous studies have reported on the preparation of core-sheath nanofibers by coaxial electrospinning for drug delivery applications. This paper summarizes the physical phenomena, the effects of various parameters in coaxial electrospinning, and the usefulness of core-sheath nanofibers in drug delivery. Furthermore, this report also highlights the future challenges involved in utilizing core-sheath nanofibers for drug delivery applications.

scholarly journals Hydrophilic PAN based carbon nanofibres with improved graphitic structure and enhanced mechanical performance using ethylenediamine functionalized graphene

RSC Advances ◽  
2017 ◽  
Vol 7 (5) ◽  
pp. 2621-2628 ◽  
Author(s):  
Zhenyu Li ◽  
Omid Zabihi ◽  
Jinfeng Wang ◽  
Quanxiang Li ◽  
Jiemin Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
High Performance ◽  
Carbon Materials ◽  
Mechanical Performance ◽  
Low Cost ◽  
Functionalized Graphene ◽  
Carbon Nanofibres ◽  
Great Opportunity ◽  
Graphitic Structure

Polyacrylonitrile (PAN) reinforced with nano-carbons such as graphene (Gr) and carbon nanotubes (CNTs) provides great opportunity for the development of low-cost and high-performance carbon materials.

Fabrication and Characterization of Chitosan-Ethylenediaminetetraacetic Acid/Polyvinyl Alcohol Blend Electrospun Nanofibers

2011 ◽  
Vol 194-196 ◽  
pp. 648-651 ◽  
Author(s):  
Natthan Charernsriwilaiwat ◽  
Praneet Opanasopit ◽  
Theerasak Rojanarata ◽  
Tanasait Ngawhirunpat
Keyword(s):  
Polyvinyl Alcohol ◽  
Ethylenediaminetetraacetic Acid ◽  
Electrospun Fiber ◽  
High Surface ◽  
Weight Ratio ◽  
Average Diameter ◽  
High Porosity ◽  
Sem Images ◽  
Fiber Mats ◽  
Small Pore

Electrospinning is a technique use to fabricate ultrafine fibers with diameters in the nanometer range. The electrospun fiber mats have high potentials for many applications, due to their high surface area to volume, high porosity and small pore size. In this study, chitosan-ethylenediaminetetraacetic acid (CS-EDTA)/polyvinyl alcohol (PVA) blend nanofibers were successfully prepared using electrospinning techniques without organic solvent. CS was dissolved in EDTA aqueous solution and then blended with PVA solution at various weight ratios. Physicochemical properties of CS-EDTA/PVA solution such as viscosity, conductivity and surface tension were investigated. The morphology and diameter of the electrospun fiber mats were analyzed by using scanning electron microscopy (SEM). The composite structure was characterized by differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FT-IR). SEM images showed that the morphology and diameter of the nanofibers were mainly affected by the weight ratio of the blend. Nanofibers were obtained when the CS-EDTA content was less than 50%wt. The average diameter of the nanofibers was 119-223 nm, and this average diameter decreased with increasing CS-EDTA content. In summary, these CS electrospun nanofiber mats may be proper for the drug delivery or wound dressing application.

Manufactory and Properties of Poly(p-Phenylenebenzobisoxazole) Aerogels Prepared by a Simple Freeze-Drying Procedure

2020 ◽  
Vol 993 ◽  
pp. 662-668
Author(s):  
Yu Nong Wei ◽  
Guang Li ◽  
Sheng Lin Yang ◽  
Jun Hong Jin
Keyword(s):  
High Performance ◽  
Freeze Drying ◽  
Sol Gel ◽  
Fire Retardant ◽  
Decomposition Temperature ◽  
High Specific Surface Area ◽  
High Porosity ◽  
Cellulose Aerogel ◽  
Small Pore ◽  
Small Pore Diameter

Aerogels based on organic high performance fibers have been attracted great attention due to its excellent thermal and mechanical properties. Here, PBO nanofiber aerogel were prepared from the super-fiber PBO through a top-down process with a sol-gel process and a simple freeze-drying process, followed by thermal cross-linking. The prepared aerogel has a small volume shrinkage, a high specific surface area of 168.9 m2 /g and a small pore diameter of 1.356 nm. Because of its 3D porous structure, it results in a low density of 6 to 30 mg/cm3 and a high porosity (98%). The aerogel retains the molecular structure of PBO at the same time, which gives it initial thermal decomposition temperature up to 500 °C and a superior fire-retardant capability. PBO aerogel possesses good compressive properties with a yield stress of 0.44MPa at 80% strain and an elasticity modulus of 1.98 MPa which is higher than SiO2 and cellulose aerogel reported.

Developing an acidproof breathable composite fabric based on fluorinated polyurethane/isotropic pitch electrospun nanofibers

2019 ◽  
Vol 50 (6) ◽  
pp. 891-905
Author(s):  
Yiqing Shao ◽  
Qingle Zhang ◽  
Jianjian Gong ◽  
Xin Xia
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Mechanical Test ◽  
Fluorine Content ◽  
Acid Resistance ◽  
Electrospun Nanofibers ◽  
Water Vapor Transport ◽  
High Porosity ◽  
Fluorinated Polyurethane ◽  
Composite Fabrics

To develop a series of novel acidproof and breathable fabric, electrospun fluorinated polyurethane/polyurethane and pitch nanofibers were directly deposited on polyester/cotton blended fabric. The layered and interpenetrated structured membranes were built to study the effects of different structures on the acidproof and breathable performances. The acidproof and breathable mechanism of different structured composite fabrics had been evaluated via emission scanning electron microscope, X-ray photoelectron spectroscopy, contact angle, porosity, pore size, comfort and mechanical test, respectively. The results showed that the layered structured composite fabric had advantages in acidproof property, i.e. the acid (H2SO4, 80%) contact angle was 130° due to the low surface energy caused by the high fluorine content (36.96%). Meanwhile, such structured composite fabric provided double protection, which made the acid-resistance pressure to reach a high value of 1050 Pa, while the interpenetrated structured composite fabric showed superior comfort and mechanical properties. Due to the high porosity (88.01%), the water vapor transport rate and air permeability were 7554.14 g/m2·24h and 46.33 mm/s, respectively. Due to the relative slip of fluorinated polyurethane/polyurethane fibers was restricted, the tensile strength and bursting strength of interpenetrated one was 1315 N and 795 N, which were higher than layered one.

A high-strength PPESK/PVDF fibrous membrane prepared by coaxial electrospinning for lithium-ion battery separator

2018 ◽  
Vol 31 (8) ◽  
pp. 948-958 ◽  
Author(s):  
Wenzheng Gong ◽  
Xinyu Wang ◽  
Zheng Li ◽  
Junfeng Gu ◽  
Shilun Ruan ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Lithium Ion ◽  
Fibrous Membrane ◽  
Coaxial Electrospinning ◽  
Mechanical And Thermal Properties ◽  
High Porosity ◽  
Hot Press ◽  
Excellent Thermal Stability ◽  
Pvdf Membrane ◽  
Electrolyte Uptake

Electrospinning fibrous membranes have attracted a great deal of attention because of their advantages, including uniform pore size, large ratio surface area, and high porosity. For extended application in lithium-ion battery, it is essential to further improve their electrochemical, mechanical, and thermal properties. In this work, a new poly (phthalazine ether sulfone ketone) (PPESK)/polyvinyli-denefluoride (PVDF) core/shell fibrous membrane was fabricated via the coaxial electrospinning technique, followed by hot press. The PPESK/PVDF membrane hot pressed at 160°C exhibits excellent comprehensive performance, including large porosity (80%), high electrolyte uptake (805%), and excellent thermal stability (at 200°C). Moreover, due to the improved bonding effect derived from the solidification of the PVDF shell layer after the hot press, the mechanical property of the membrane is effectively enhanced. The electrochemical tests also indicate that the PPESK/PVDF membrane shows larger ionic conductivity and lower interfacial resistance when compared with commercial microporous polypropylene separator. In addition, simulated cells assembled with the PPESK/PVDF membrane present superior discharge capacity, stable cycle performance, and excellent rate capability. Therefore, the hot-pressed coaxial PPESK/PVDF fibrous membrane has the potential to be a promising candidate as the separator for high-performance lithium-ion battery.

Effect of Blend Ratio on Morphology and Swelling Properties of PVA/Chitosan Nanofibers

2017 ◽  
Vol 901 ◽  
pp. 79-84 ◽  
Author(s):  
Nasikhudin ◽  
Intan Puspitasari ◽  
Markus Diantoro ◽  
Ahmad Kusumaatmaja ◽  
Kuwat Triyana
Keyword(s):  
Pore Size ◽  
Smooth Surface ◽  
Fiber Diameter ◽  
High Porosity ◽  
Swelling Properties ◽  
Blend Ratio ◽  
Small Pore Size ◽  
Small Pore ◽  
Electrospinning Method ◽  
Solution Increase

PVA/chitosan nanofibers have been prepared by electrospinning method. A novel nanofibers mat was prepared in a various blend ratio of PVA to chitosan. The structure of PVA/chitosan nanofibers was examined by FTIR and SEM. The results showed that PVA/chitosan nanofibers were successfully formed. The result of FTIR indicates that PVA and chitosan exist in PVA/chitosan Nanofibers. SEM observation showed that the fiber has several hundred nanometers with a smooth surface. It also observed that fibers diameters decreased by increase percentage of chitosan, this occurs because of the conductivity of electrospun solution increase and the viscosity decrease. Reduction of fiber diameter followed by a decrease in pore size, this is a very important property of a membrane having a small pore size with high porosity. PVA/chitosan nanofibers have pH sensitive of swelling properties and better-swelling properties in acid conditions.

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