Preparation of Polyacrylamide Nanofibers by Electrospinning

2009 ◽  
Vol 87-88 ◽  
pp. 433-438 ◽  
Author(s):  
Li Liu ◽  
Wei Wei Gu ◽  
Wen Ting Xv ◽  
Chang Fa Xiao
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Applied Voltage ◽  
Diameter Distribution ◽  
Uniform Thickness ◽  
Technological Parameters ◽  
Glutaraldehyde Solution ◽  
Scanning Electron

Polyacrylamide (PAM) nanofibers was spun by electrospinning. In order to increase the molecular weight of the PAM, It has been cross linked by Glutaraldehyde solution. By means of scanning electron microscopy (SEM), the effect of electrospun technological parameters on the fibers’ morphology were researched. The parameters include the concentration of PAM spinning solution, the applied voltage and tip-collector distance (TCD). The PAM nanofibers of uniform thickness with the fibers’ diameter distribution of 80 ~ 160nm were got under the conditions as followers: the concentration of 16 wt.%, applied voltage of 23 kV, the TCD of 13cm.

scholarly journals Effect of the dispersion of the chromophore on the optical performances of polarizers from polyethylene and 5”-thio- (3-butyl)nonyl-2,2’:5’,2”-terthiophene

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Andrea Pucci ◽  
Letizia Moretto ◽  
Giacomo Ruggeri ◽  
Francesco Ciardelli
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Melting Point ◽  
Drawing Ratio ◽  
Scanning Calorimetry ◽  
Affine Deformation ◽  
Ultra High Molecular Weight ◽  
Scanning Electron

AbstractA new polyethylene-compatible terthiophene chromophore, 5”-thio-(3- butyl)nonyl-2,2’:5’,2”-terthiophene, with melting point lower than 0°C was prepared and used for linear polarizers based on ultra-high-molecular-weight polyethylene (UHMWPE). Differential scanning calorimetry and scanning electron microscopy indicate that the new chromophore is dispersed uniformly in films of UHMWPE obtained by casting from solution. The films show excellent dichroic properties (dichroic ratio 30) at rather low drawing ratio (≈ 20) . Moreover, qualitative agreement is observed with the Ward pseudo-affine deformation scheme.

scholarly journals Experimental Research into Technology of Abrasive Flow Machining Nonlinear Tube Runner

2014 ◽  
Vol 6 ◽  
pp. 752353 ◽  
Author(s):  
Junye Li ◽  
Lifeng Yang ◽  
Weina Liu ◽  
Xuechen Zhang ◽  
Fengyu Sun
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Quality ◽  
Experimental Research ◽  
The Self ◽  
Technological Parameters ◽  
Abrasive Flow Machining ◽  
Overall Performance ◽  
Scanning Electron

In the fields of military and civil uses, some special passages exist in many major parts, such as non-linear tubes. The overall performance is usually decided by the surface quality. Abrasive flow machining (AFM) technology can effectively improve the surface quality of the parts. In order to discuss the mechanism and technology of abrasive flow machining nonlinear tube, the nozzle is picked up as the researching object, and the self-designed polishing liquid is employed to make research on the key technological parameters of abrasive flow machining linear tube. Technological parameters’ impact on surface quality of the parts through the nozzle surface topography and scanning electron microscopy (SEM) map is explored. It is experimentally confirmed that abrasive flow machining can significantly improve surface quality of nonlinear runner, and experimental results can provide technical reference to optimizing study of abrasive flow machining theory.

scholarly journals Scanning Electron Microscopy Analysis of Changes of Hydroxiapatite/Poly-L-Lactide with Different Molecular Weight of PLLAaAfter Intraperitoneal Implantation

2016 ◽  
Vol 66 (2) ◽  
pp. 234-244
Author(s):  
Ljubiša Đorđević ◽  
Stevo Najman ◽  
Perica Vasiljević ◽  
Miroslav Miljković ◽  
Nenad Ignjatović ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Bone Tissue ◽  
Tissue Loss ◽  
Practical Applications ◽  
Molecular Weights ◽  
Significant Difference ◽  
Tissue Reactions ◽  
Scanning Electron

Abstract Implantation of a biomaterial is one of the important trends in solving the problem of bone tissue loss. Calcium hydroxiapatite (HAp), as the most representative bone component is a serious candidate for such implantations. The synthetic polymer poly-L-lactide (PLLA) in HAp/PLLA is often used as a polymeric material, with a role in the substitution of bone tissue collagen fibers. Fibers of PLLA may strengthen HAp and its good bioresorption provides space for tissue remodeling. Differences in porosity, microstructure, compressive consistency as well as bioresorbility of HAp/ PLLA may be achieved by using PLLA with different molecular weights. In this study HAp/PLLA composites with PLLA of different molecular weights (50,000; 160,000 and 430,000) were implanted in mouse peritoneum in order to examine the influence of the molecular weight of PLLA on morphology changes. Microstructural changes of biomaterial (HAp/PLLA) surface were analyzed one week, three weeks and four months after their implantation using Scanning Electron Microscopy. The results showed a significant difference in tissue reactions on the applied biocomposites, depending on their molecular weight. The most intense proliferation of cells was induced by HAp/PLLA 50,000 compared to HAp/PLLA 430,000 and HAp/PLLA 160,000. In the vicinity of HAp/PLLA 430,000 abundant erythrocytes were observed. The differences in biological reactions on the examined biocomposites are significant for their practical applications. HAp/PLLA composite biomaterials of different types and resorption rates require specific designing and programming to become suitable for particular purposes in an organism.

Preparation of Polyurethane (PU)/ Polyaniline (PANI) Compound Nanofiber via Electrospinning

2011 ◽  
Vol 332-334 ◽  
pp. 1352-1356
Author(s):  
Li Wei Liu ◽  
Wei Min Kang ◽  
Bo Wen Cheng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrospun Nanofibers ◽  
Total Solid ◽  
Solution Concentration ◽  
Solid Content ◽  
Diameter Distribution ◽  
Mass Ratio ◽  
Total Solid Content ◽  
Scanning Electron

In this paper polyurethane (PU) / polyaniline (PANI) nanofibers were successfully prepared via electrospinning with N, N-dimethylformamide (DMF) and tetrahydrofuran (THF) mixture (1:2 mass ratio). The morphology, diameter and structure of the electrospun nanofibers were examined by scanning electron microscopy (SEM) and the diameter distribution of nanofibers was measured by Image-Pro Plus. Results indicate that the morphology, diameter and uniformity of the fibers were influenced by solution concentration, applied voltage, capillary–screen distance and flow rate greatly, and the finer and uniform nanofibers were electrospun from total solid content of the spinning solutions at 8 wt. %, PU and PANI with ratio of 10/1 (w/w), the spinning voltage at 35 kV, the collecting distance at 15 cm and the extruding speed at 6 ml/h.

Fracture of Polymers Under Repetitive Loading

1986 ◽  
Vol 79 ◽  
Author(s):  
J. A. Sauer ◽  
C. C. Chen
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Fracture Surface ◽  
Surface Morphology ◽  
Thermal Effects ◽  
Second Phase ◽  
Fracture Surface Morphology ◽  
Repetitive Loading ◽  
Scanning Electron

AbstractThe fracture surface morphology of various polymer specimens, fractured under alternating loading, has been examined by scanning electron microscopy. Illustrations are given of both typical and unusual fracture surfaces and the influence of such variables as composition, molecular weight, presence of a dispersed second phase and induced thermal effects is discussed.

The Effects of Organic Solvent on the Electrospinning of Water-Soluble Polyacrylamide with Ultrahigh Molecular Weight

2007 ◽  
Vol 121-123 ◽  
pp. 113-116
Author(s):  
Yi Yang Zhao ◽  
X. Li ◽  
C. Wang ◽  
L.J. Li
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Organic Solvent ◽  
Colloidal Particles ◽  
Water Soluble ◽  
Ultrahigh Molecular Weight ◽  
Scanning Electron

The effects of an organic solvent on the electrospinning of water-soluble polyacrylamide with ultrahigh molecular weight were investigated. An organic solvent, DMF, was introduced to the polyacrylamide aqueous solution and subsequently, transparent spinning solutions were obtained. The spinning solution was electrospun at the voltage of 10 kV and the electrospun products were examined by scanning electron microscopy (SEM). Results indicated that all the electrospinning products including colloidal particles, beaded fibers and smooth fibers were fabricated in the DMF/H2O bi-component solvent and the morphology of electrospun products changed from smooth fiber to beaded fiber with the increasing amount of DMF used.

scholarly journals Effect of the molecular weight of polyvinylpyrrolidone on the structure and morphology of materials based on substituted hydroxyapatite for bone implants

2018 ◽  
Vol 226 ◽  
pp. 03012
Author(s):  
Elizaveta A. Mukhanova ◽  
Inna A. Suprunova ◽  
Yana A. Suprunova ◽  
Igor Yu. Zabiyaka
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Thermodynamic Stability ◽  
Structural Transformations ◽  
Experimental Results ◽  
Molecular Weights ◽  
Structure And Morphology ◽  
Size And Morphology ◽  
Scanning Electron

In this work, we study the influence of various molecular weights of polyvinylpyrrolidone (PVP) on synthesis substituted hydroxyapatite. Using the scanning electron microscopy we estimated the size and morphology of the particle. We studied the structural transformations of phosphates and the effect of polymer sizes on the structure and morphology. We revealed the thermodynamic stability of the structure of hydroxyapatite due to experimental results.

Preparation and Study of P(Styrene-Divinylbenzene)/Polyacrylamide Particles

2014 ◽  
Vol 1004-1005 ◽  
pp. 282-285
Author(s):  
Jian Li Wang ◽  
Zhong Hua Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Infrared Spectroscopy ◽  
Emulsion Polymerization ◽  
Diameter Distribution ◽  
Step Method ◽  
Styrene Divinylbenzene ◽  
Concentrated Emulsion ◽  
Scanning Electron

The micro-sized p(styrene-1,4-divinylbenzene)/polyacrylamide(p(St-DVB)/pAM) particles were prepared by a two-step method. P(St-DVB) cores were firstly obtained via concentrated emulsion polymerization, and then the cores were swelled sufficiently and reacted with acrylamide until p(St-DVB)/pAM particles were obtain. The morphologies and compositions of p(St-DVB)/pAM particles were characterized by scanning electron microscopy(SEM) and infrared spectroscopy(IR) individually. It was proved that the micro-morphologies of p(St-DVB)/pAM particles were nearly spherical or even peanut shape. It was also found that the diameter distribution of p(St-DVB)/pAM particles became narrower with the increasing of DVB amounts, and the same trade was also observed on emulsifier amounts.

scholarly journals Changes in the Molecular Characteristics of Bovine and Marine Collagen in the Presence of Proteolytic Enzymes as a Stage Used in Scaffold Formation

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 502
Author(s):  
Marfa N. Egorikhina ◽  
Ludmila L. Semenycheva ◽  
Victoria O. Chasova ◽  
Irina I. Bronnikova ◽  
Yulia P. Rubtsova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Proteolytic Enzymes ◽  
Molecular Characteristics ◽  
Species Origin ◽  
Bovine Collagen ◽  
Hydrolyzed Collagen ◽  
Source Materials ◽  
Scanning Electron

Biopolymers, in particular collagen and fibrinogen, are the leading materials for use in tissue engineering. When developing technology for scaffold formation, it is important to understand the properties of the source materials as well as the mechanisms that determine the formation of the scaffold structures. Both factors influence the properties of scaffolds to a great extent. Our present work aimed to identify the features of the molecular characteristics of collagens of different species origin and the changes they undergo during the enzymatic hydrolysis used for the process of scaffold formation. For this study, we used the methods of gel-penetrating chromatography, dynamic light scattering, reading IR spectra, and scanning electron microscopy. It was found that cod collagen (CC) and bovine collagen (BC) have different initial molecular weight parameters, and that, during hydrolysis, the majority of either type of protein is hydrolyzed by the proteolytic enzymes within the first minute. The differently sourced collagen samples were also hydrolyzed with the formation of two low molecular fractions: Mw ~ 10 kDa and ~20 kDa. In the case of CC, the microstructure of the final scaffolds contained denser, closely spaced fibrillar areas, while the BC-sourced scaffolds had narrow, short fibrils composed of unbound fibers of hydrolyzed collagen in their structure.

scholarly journals TAYLOR CONE–JET MODE IN THE FABRICATION OF ELECTROSPRAYED MICROSPHERES

2018 ◽  
Vol 55 (1B) ◽  
pp. 216 ◽  
Author(s):  
Viet Linh Nguyen - Vu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polymer Solution ◽  
Flow Rate ◽  
Applied Voltage ◽  
Processing Parameters ◽  
Taylor Cone ◽  
Sem Micrographs ◽  
Scanning Electron

In this study, electrospray modes were investigated to clarify their effects on the morphology and size of polycaprolactone (PCL) particles. The result indicated that electrosprayed microspheres with homogeneous and stable morphology were fabricated by using cone–jet mode and suitable electrospray processing parameters. Besides, the PCL solution was created by dissolving in dichloromethane with different concentrations such as 3.5%, 4%, 4.5% and 5%. The scanning electron microscopy (SEM) micrographs pointed that electrosprayed PCL microspheres were formed by using 4.5 % polymer solution. In addition, the reproducible and homogeneous morphology of PCL microparticles were obtained at the following set of parameters: applied voltage of 18 kV, flow rate of 1.5 mL/h and distance tip to collector of 20 cm. Moreover, at the collecting distance of 15–25 cm, the flow rate of 1.2–1.8 mL/h and applied voltage of 18 kV the cone–jet mode was generated. It was an effective electrospray mode to create stable and homogeneous microspheres.

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