Analysis of the Process Parameters for Obtaining a Stable Electrospun Process in Different Composition Epoxy/Poly ε-Caprolactone Blends with Shape Memory Properties

In this work Poly ε-caprolactone (PCL)/ Diglycidyl ether of bisphenol A (DGEBA) blends were electrospun and the obtained mats were UV cured to achieve shape memory properties. In the majority of studies, when blends with different compositions are electrospun, the process variables such as voltage or flow rate are fixed independently of the composition and consequently the quality of the fibers is not optimized in all of the range studied. In the present work, using the design of experiments methodology, flow rate and voltage required to obtain a stable process were evaluated as responses in addition to the fiber diameter and shape memory properties. The results showed that the solution concentration and amount of PCL played an important role in the voltage and flow rate. For the shape memory properties excellent values were achieved and no composition dependence was observed. In the case of fiber diameter, similar results to previous works were observed.

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Thermomechanical and shape-memory properties of epoxy-based shape-memory polymer using diglycidyl ether of ethoxylated bisphenol-A

Smart Materials and Structures ◽

10.1088/0964-1726/22/5/055034 ◽

2013 ◽

Vol 22 (5) ◽

pp. 055034 ◽

Cited By ~ 21

Author(s):

Mengjin Fan ◽

Heng Yu ◽

Xiangyuan Li ◽

Jue Cheng ◽

Junying Zhang

Keyword(s):

Bisphenol A ◽

Shape Memory ◽

Shape Memory Polymer ◽

Diglycidyl Ether ◽

Shape Memory Properties

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Effect of Electrospinning Parameters on the Fiber Diameter and Morphology of PLGA Nanofibers

Dental Oral Biology and Craniofacial Research ◽

10.31487/j.dobcr.2021.02.04 ◽

2021 ◽

pp. 1-7

Author(s):

Yuanyuan Duan ◽

Lohitha Kalluri ◽

Megha Satpathy ◽

Yuanyuan Duan

Keyword(s):

Bone Regeneration ◽

Flow Rate ◽

Applied Voltage ◽

Fiber Diameter ◽

Solution Concentration ◽

Electrospun Fibers ◽

High Porosity ◽

The Mean ◽

Nanoscale Fibers ◽

One Way Anova

Background: Poly lactic-co-glycolic acid (PLGA) has been widely investigated for various biomedical applications, such as craniofacial bone regeneration, wound dressing and tissue engineering. Electrospinning is a versatile technology used to produce micro/nanoscale fibers with large specific surface area and high porosity. Purpose: The aim of the current study is to prepare PLGA nanofibers using electrospinning for guided tissue regeneration/guided bone regeneration applications. The objective of this study is to determine the appropriate electrospinning parameters such as applied voltage, flow rate, spinneret-collector distance and polymer solution concentration for preparation of PLGA fibrous membrane and their effect on the mean fiber diameter of the electrospun fibers. Method: PLGA pellets were dissolved in Hexafluoroisopropanol (HFIP) in various concentrations overnight using a bench rocker. The resulting PLGA solution was then loaded into a syringe and electrospinning was done by maintaining the other parameters constant. Similarly, various fibrous mats were collected by altering the specific electrospinning parameter inputs such as applied voltage, flow rate and spinneret-collector distance. The morphology of the fibrous mats was characterized using Scanning Electron Microscope. The mean fiber diameter was assessed using ImageJ software and the results were compared using one-way ANOVA. Results: We obtained bead-free uniform fibers with various tested solution concentrations. One-way ANOVA analysis demonstrated significant variation in mean fiber diameter of the electrospun fibers with altering applied voltage, solution concentration, flow rate and spinneret-collector distance. Conclusion: The above-mentioned electrospinning parameters and solution concentration influence the mean fiber diameter of electrospun PLGA nanofibers.

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Shape-Memory Properties of Electrospun Non-wovens Prepared from Amorphous Polyetherurethanes Under Stress-free and Constant Strain Conditions

MRS Proceedings ◽

10.1557/opl.2012.251 ◽

2012 ◽

Vol 1403 ◽

Cited By ~ 6

Author(s):

Tilman Sauter ◽

Karl Kratz ◽

Andreas Lendlein

Keyword(s):

Shape Memory ◽

Shape Recovery ◽

Fiber Diameter ◽

Tensile Tests ◽

Polymer Chains ◽

Single Fiber ◽

Elongation At Break ◽

Shape Memory Properties ◽

Degree Of Orientation ◽

Shape Fixity

ABSTRACTThe shape-memory properties of electrospun polyetherurethanes (PEU) non-wovens with a single fiber diameter of around 1 μm were explored. In uniaxial cyclic, thermomechanical tensile tests a dual-shape shape-memory creation procedure (SMCP) was applied and the shape recovery was examined under stress-free and constant strain conditions. The thermal properties of the electrospun PEU non-wovens were found to be similar to those obtained for bulk PEU samples, whereas the mechanical properties revealed differences with respect to the elongation at break (εb) at increased temperatures. Excellent dual-shape properties were achieved for the PEU non-wovens with a high shape fixity rate (Rf) and shape recovery rate (Rr). A significant higher recovery stress (σmax) was obtained under constant strain recovery conditions for the electrospun non-wovens compared to the bulk PEU samples, which might be attributed to the higher degree of orientation of the polymer chains in the microfibers. Therefore the influence of different (single) fiber diameters as well as the variation of the programming elongation εm and temperature Tprog on σmax is an interesting issue for future investigations.

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The Effect of Flow Rate on Morphology and Deposition Area of Electrospun Nylon 6 Nanofiber

Journal of Engineered Fibers and Fabrics ◽

10.1177/155892501200700414 ◽

2012 ◽

Vol 7 (4) ◽

pp. 155892501200700 ◽

Cited By ~ 33

Author(s):

Shamim Zargham ◽

Saeed Bazgir ◽

Amir Tavakoli ◽

Abo Saied Rashidi ◽

Rogheih Damerchely

Keyword(s):

Droplet Size ◽

Flow Rate ◽

Fiber Diameter ◽

Electrospun Nanofibers ◽

Solution Concentration ◽

Nylon 6 ◽

Taylor Cone ◽

Diameter Distribution ◽

Deposition Area ◽

Fiber Diameter Distribution

Electrospinning is a process that produces continuous polymer fibers with diameters of a nanometric scale. Nylon 6 in formic acid was electrospun to obtain the nanofibers. Fibers with different diameters were obtained using flow rates of 0.1, 0.5, 1 and 1.5 mL/hr, 20 wt% solution concentration, with an applied voltage of 20 kV and 15 cm spinning distance. Flow rate influenced the fiber diameter distribution, droplet size and its initiating shape at the capillary tip, the trajectory of the jet, maintenance of Taylor cone, areal density and nanofiber morphology. The morphology of the electrospun nanofibers was analyzed by using the scanning electron microscope (SEM). The effect of flow rate on the deposition area was also investigated for better control of the process. It was observed that a stabilized Taylor cone, small average droplet size, narrowest fiber diameter distribution, more stability in the originating jet, and uniform morphology of nanofiber is obtained at a flow rate of 0.5 mL/hr.

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Dynamic mechanical and shape memory properties of copolymers based on o -allylphenol type benzoxazines and diglycidyl ether of bisphenol-A

Polymer International ◽

10.1002/pi.5635 ◽

2018 ◽

Vol 67 (9) ◽

pp. 1266-1274 ◽

Cited By ~ 3

Author(s):

Shanshan Shen ◽

Cuiyun Li ◽

Huiyun Yang ◽

Yanyu Zhang ◽

Fengan Han ◽

...

Keyword(s):

Bisphenol A ◽

Shape Memory ◽

Diglycidyl Ether ◽

Dynamic Mechanical ◽

Shape Memory Properties

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Effect of calcium ion implantation and of immersion in Hank's solution on shape memory properties of Ti-Ni alloy

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:20031079 ◽

2003 ◽

Vol 112 ◽

pp. 1121-1124

Author(s):

T. Asaoka ◽

S. Nakazawa

Keyword(s):

Ion Implantation ◽

Shape Memory ◽

Calcium Ion ◽

Ni Alloy ◽

Shape Memory Properties ◽

Hank’S Solution

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STUDY OF INACCURACY IN THE OPERATION OF THE MAIN CONTROLLER OF STB MACHINE

АГРАРНЫЙ ВЕСТНИК ВЕРХНЕВОЛЖЬЯ ◽

10.35523/2307-5872-2019-27-2-99-102 ◽

2019 ◽

Keyword(s):

Normal Distribution ◽

Stable Process ◽

Random Errors ◽

Actual Length ◽

Experimental Data Processing ◽

Set Up ◽

Main Regulator ◽

Transmission Gear ◽

Selection Of

At production of fabrics, including fabrics for agricultural purpose, an important role is played by the cor-rect adjustment of operation of machine main regulator. The quality of setup of machine main controller is determined by the proper selection of rotation angle of warp beam weaving per one filling thread. In the pro-cess of using the regulator as a result of mistakes in adjustment, wear of transmission gear and backlashes in connections of details there are random changes in threads length. The purpose of the article is the research of property of random errors of basis giving by STB machine regulator. Mistakes can be both negative, and positive. In case of emergence only negative or only positive mistakes operation of the machine becomes im-possible as there will be a consecutive accumulation of mistakes. As a result of experimental data processing for stable process of weaving and the invariable diameter of basis threads winding of threads it is revealed that the random error of giving is set up as linear function of the accidental length having normal distribution. Measurements of accidental deviations in giving of a basis by the main regulator allowed to construct a curve of normal distribution of its actual length for one pass of weft thread. The presented curve of distribution of random errors in giving of a basis is the displaced curve of normal distribution of the accidental sizes. Also we define the density of probability of normal distribution of basis giving errors connected with a margin er-ror operation of the main regulator knowing of which allows to plan ways of their decrease that is important for improvement of quality of the produced fabrics.

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Radon removal by aeration: observations on testing, installation and maintenance of domestic treatment units

Water Science & Technology Water Supply ◽

10.2166/ws.2009.449 ◽

2009 ◽

Vol 9 (4) ◽

pp. 469-475

Author(s):

T. Turtiainen

Keyword(s):

Water Quality ◽

Water Flow ◽

Removal Efficiency ◽

Flow Rate ◽

Test Protocol ◽

Household Water ◽

Medium Flow ◽

Removal Efficiencies ◽

Frequent Sampling

Radon is one of the contaminants that sometimes impair the water quality of wells, especially those drilled in bedrock. Domestic radon removal units based on aeration have been commercially available for more than ten years. In order to determine how effectively these units remove radon a new test protocol applying frequent sampling while letting 100 litres of water flow, was developed. This way, removal efficiencies can be more accurately calculated and possible malfunctions detected. Seven models of domestic aerators designed for removing radon from household water were tested. The aerators were based on diffused bubble aeration, spray aeration or jet aeration. The average removal efficiencies for 100 litres with a medium flow rate were 86–100% except for a unit that circulated the aerated water back to the well that had removal efficiency of 80% at the maximum. By conducting a questionnaire study usual problems related to the aeration units were localized and recommendations on maintenance and installation are given accordingly.

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