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.

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.

A Bipedal Silica-Immobilized Azo-Initiator for Surface-Confined Radical Polymerizations

2009 ◽  
Vol 62 (11) ◽  
pp. 1473 ◽  
Author(s):  
Robert Rotzoll ◽  
Philipp Vana
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Methyl Acrylate ◽  
Chain Transfer ◽  
Molecular Weights ◽  
Surface Initiated Polymerization ◽  
Reversible Addition ◽  
Azo Initiator ◽  
Scanning Electron

The present study introduces the silica-anchored azo-initiator 4,4′-azobis(4-cyano-N-(3″-triethoxysilylpropyl)-valeric amide) (ACTA) for the surface-initiated polymerization of methyl acrylate (MA) with and without additional grafted reversible addition–fragmentation chain transfer (RAFT) agents 1,4-bis(3′-trimethoxysilylpropyltrithiocarbonylmethyl)benzene and 1,6-bis(o,p-2′-trimethoxysilylethylbenzyltrithiocarbonyl)hexane. While the sole use of silica-linked ACTA produced grafted poly(methyl acrylate) (pMA) of high molecular weight, due to a 2D Trommsdorff effect, the polymerization in combination with the fixed RAFT agents exhibited living behaviour with increasing molecular weights during polymerization. Silica-pMA hybrids were further analyzed via thermogravimetric analysis and scanning electron microscopy, which revealed significant differences between the three approaches.

scholarly journals Molecular spectroscopy analysis of the substitution of bone tissue by HAp/PLLA composite biomaterial

2004 ◽  
Vol 18 (4) ◽  
pp. 553-565 ◽  
Author(s):  
Nenad Ignjatovic ◽  
Dragan Uskokovic
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Ir Spectroscopy ◽  
Molecular Spectroscopy ◽  
Absorption Bands ◽  
Molecular Weights ◽  
Ft Ir ◽  
Scanning Electron ◽  
Ft Ir Spectroscopy

Due to its pronounced osteoinductive properties, calcium hydroxyapatite (HAp) has been widely used in medicine. Bioresorptive poly-L-lactide (PLLA) as a polymer biomaterial has been also used extensively in medicine for its non-toxicity and biocompatibility. To combine the advantages exhibited by each of these materials, a HAp/PLLA composite biomaterial has been synthesized and used for reconstruction and repair of bone defects. Hydroxyapatite/poly-L-lactide (HAp/PLLA) composite biomaterial with PLLA of 50,000 and 430,000 g/mole molecular weight was studiedin vivo. The biocomposite with PLLA of both molecular weights was implanted into mice, then removed from their organisms and analyzed by the Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and histopathologic analysis. Characteristic absorption bands, registered and defined by FT-IR spectroscopy, confirm the formation of new functional groups and compounds during the bone repair process using HAp/PLLA biocomposite with PLLA of 50,000 and 430,000 molecular weights. Analysis of the microstructures of the sample surfaces by scanning electron microscopy (SEM) before and after implantation revealed bioresorption of the PLLA polymer phase in the system with PLLA of lower molecular weight and generation of collagen fibers at the sites of implanted bioresorptive PLLA. As the studied synthetic materials behave as the natural bone, i.e., they are phagocytosed and resorpable, they can be considered as biocompatible.

scholarly journals Cinnamyl-Imine-Chitosan Hydrogels. Morphology Control

2018 ◽  
Vol 26 (2) ◽  
pp. 221-232
Author(s):  
Anda M. Craciun
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Functional Groups ◽  
Molar Ratio ◽  
Crosslinking Degree ◽  
Molecular Weights ◽  
Amine Groups ◽  
Chitosan Hydrogels ◽  
Scanning Electron

Abstract The study deals with the exploration of the possibilities to control the morphology of cinnamyl-imine-chitosan hydrogels in view of their bio-application. Three series of hydrogels were synthetized from chitosan of three different molecular weights and cinnamaldehyde, varying the molar ratio between the amine groups on chitosan and aldehyde functional groups. The hydrogel morphology has been monitored by scanning electron microscopy. The variation of the hydrogel morphology as a function of chitosan molecular weight, crosslinking degree, and incubation conditions has been monitored. It was concluded that there are multiple possibilities of tuning the morphology of these hydrogels in function of the targeted application.

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.

Characteristic of a Novel Composite Inorganic Polymer Coagulant-PAZF Prepared from Industrial Wastes

2014 ◽  
Vol 977 ◽  
pp. 82-85
Author(s):  
Ming Li ◽  
Yan Zhen Yu ◽  
Juan Ting Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Complex Compounds ◽  
Industrial Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Coagulation Performance ◽  
Composite Coagulant ◽  
Scanning Electron

A new composite coagulant polymeric aluminum zinc ferric (PAZF) was synthesized from industrial wastes. The structure and morphology of the coagulant was characterized by X-ray Diffraction (XRD), Infrared Spectroscopy (IR) and Scanning Electron Microscopy (SEM) and the coagulation performances were evaluated by dyeing-printing wastewater treatment. The results show that new complex compounds are formed in PAZF. Compared with poly aluminum chloride (PAC), the contents of ionic polymerized bonds and the cross-copolymerization among Fe (III), Al (III) and Zn (II) hydroxyl polymerized bonds are increase obviously, and the surface morphology of PAZF presents a net-like structure with the longer molecular chain. Coagulation experiments indicate that PAZF exhibits better coagulation performance in removing turbidity, COD and chromaticity.

scholarly journals Structure and Morphology Properties of Nanoparticle Hematite Pigment from Lathe Waste

2021 ◽  
Vol 13 (1) ◽  
pp. 21
Author(s):  
Lilik Miftahul Khoiroh ◽  
Asmaul Dwi Ayu Sholekah ◽  
Eny Yulianti
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Crystallinity Degree ◽  
X Ray ◽  
Structure And Morphology ◽  
Calcination Method ◽  
Scanning Electron ◽  
Color Reader

Hematite coated PEG was synthesized by the sonication-calcination method. A variation of Na2CO3 is investigated to know the effect on structure and morphology. Characterization of samples are using X-ray fluorescence, X-ray diffraction, Scanning electron microscopy, and color reader techniques. XRF data showed that iron is the highest element in the precursor. The X-ray diffraction data confirm that Fe(OH)3, α-FeOOH, and Fe3O4 established at the sonication stage are then transformed into the α-Fe2O3 phase after calcination. The X-ray diffraction data also was found that α-Fe2O3 at 0.5 M formed with the highest crystallinity degree. The scanning electron microscopy showed that the particle's shape is spherical, bar-shaped, and aggregate. However, the distribution of particles is not uniform and still displays agglomeration. The Color reader shows the highest degree of lightness obtained is at 1 M variation.

The Fracture Failure Analysis of Precision Centrifuge Spindle

2014 ◽  
Vol 971-973 ◽  
pp. 802-805
Author(s):  
Wei Feng Zhang ◽  
Li Yan ◽  
Fu Xia Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Fracture Mechanics ◽  
Failure Analysis ◽  
Fatigue Failure ◽  
High Speed ◽  
Experimental Results ◽  
Fracture Failure ◽  
Scanning Electron

For the problem of high-speed rotating centrifuge spindle fracture failures, relevant analyses are conducted from the perspective of microstructure, chemical composition and fracture mechanics by using scanning electron microscopy and related instruments. Experimental results and analyses indicate that the spindle fracture is fatigue failure, mainly caused by cold cracks generated on the journal surfacing. Based on the analysis results, improvements and measures are suggested to better solve the spindle weld fracture failure problems.

SYNTHESIS, MORPHOLOGY AND STRUCTURAL PROPERTIES OF (GD,ND)SR2RUCU2O8 SAMPLES

2003 ◽  
Vol 17 (04n06) ◽  
pp. 899-904 ◽  
Author(s):  
A. VECCHIONE ◽  
M. GOMBOS ◽  
C. TEDESCO ◽  
A. IMMIRZI ◽  
L. MARCHESE ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid State Reaction ◽  
X Ray ◽  
Structure And Morphology ◽  
Polycrystalline Powder ◽  
Scanning Electron

NdSr 2 RuCu 2 O x material has been prepared as polycrystalline powder by solid state reaction. The compound has been investigated by synchrotron x-ray powder diffraction and scanning electron microscopy. The experimental results show that the average crystal structure is a disordered cubic perovskite with Nd and Sr cations occupying the same site and the same substitution is found for Cu and Ru atoms. A comparison between the crystal structure and morphology of this compound and the superconducting tetragonal GdSr 2 RuCu 2 O 8 is also discussed.

Magnesium Nitrate as Additive for Synthesis of Mg(OH)2 Nanoparticles

2012 ◽  
Vol 198-199 ◽  
pp. 99-102
Author(s):  
Qing Gang Kong ◽  
Hai Yan Qian
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Temperature ◽  
Magnesium Nitrate ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Size And Morphology ◽  
Scanning Electron

Magnesium nitrate was used as additive for synthesis of Mg(OH)2 (MH) nanoparticles at low temperature (70°C). Mg(OH)2 nanoparticles have platelet-like structure and approximately 40-60nm in thicknesses. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were applied to characterize the crystal phase. The supersaturation degree of solution effects the size and morphology of MH nanoparticles.

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