Kaolinite dispersion in cassava starch-based composite films: a photonic microscopy and X-ray tomography study

2018 ◽  
Vol 38 (7) ◽  
pp. 641-647
Author(s):  
Jean Aimé Mbey ◽  
Fabien Thomas ◽  
Sandrine Hoppe

Abstract In the present study, a combined use of photonic microscopy, scanning electron microscopy and 3D X-ray tomography is carried out in order to analyze the dispersion and the distribution of raw and dimethyl sulfoxide (DMSO)-intercalated kaolinite used as filler in cassava starch-based films. It is shown that the association of these techniques allows a valuable analysis of clay dispersion in polymer-clay composite films. In the case of kaolinite-starch composite films on which this study is focused, it is obvious that previous intercalation of kaolinite with DMSO is an efficient way to improve dispersion and distribution of kaolinite in a starch polymer matrix.

2022 ◽  
Vol 92 (3) ◽  
pp. 435
Author(s):  
А.М. Камалов ◽  
В.В Kодолова-Чухонцева ◽  
E.Н Дресвянина ◽  
T.П Масленникова ◽  
И.П Добровольская ◽  
...  

Using the methods of X-ray diffraction and scanning electron microscopy, the structure of composite films based on chitosan and single-wall carbon tubes has been studied. It is shown that the introduction of carbon nanotubes leads to the ordering of the chitosan structure. Increase in concentration of nanotubes (from 0 to 3%) causes rise in the value of storage modulus from 3 to 4 GPa (DMA data), increase in electrical conductivity of samples (from 10-11 to 102 S/m), and some changes in their dielectric permittivity (from 5.5. to 26 at an electrical field frequency of 1kHz). Data on the ionic and electronic components of the conductivity of the composite film are presented.


2016 ◽  
Vol 6 (1) ◽  
pp. 17
Author(s):  
Saule Kudaikulova ◽  
Galina Boiko ◽  
Bulat Zhubanov ◽  
N. Ashurov ◽  
Sh. Sodykov ◽  
...  

The formulation of macromolecular blends on the basis of polyimides using one step catalytic polycyclocondensation is reported. Polymers with active functional groups (polyacrylamide, polycaproamide) have been suggested as catalysts for the reaction of alicyclic dianhydrides with aromatic diamines in protolytic medium. Films made from macromolecular blends of synthesized polymers have been investigated by X-ray diffractometry and scanning electron microscopy. It has been shown that single step formation of polyimide on the polymer matrix presents the possibility to prepare thin structured disperse blends in comparison with simple mixing of homopolymers.


2012 ◽  
Vol 268-270 ◽  
pp. 45-48 ◽  
Author(s):  
Wen Ting Li ◽  
Ya Ting Wang ◽  
Xu Chun Song

Poly(3-methoxythiophene)/NiO (PMOT/NiO) composite films were electrochemically synthesized on a ITO surface in the ionic liquid 1-butyl-3-metyllimidazolium hexafluorophosphate ([BMIM]PF6) by a potentiodynamic polymerization method. The PMOT/NiO composite films were characterized by energy-dispersive X-ray analysis(EDS) and scanning electron microscopy (SEM). Electrochemistry properties of the prepared film was characterized by cyclic voltammetry. Spectroelectrochemistry and electrochromic properties of the PMOT/NiO composite were characterized using various experiment techniques in [BMIM]PF6.


2019 ◽  
Vol 39 (3-4) ◽  
pp. 95-110 ◽  
Author(s):  
Nissapa Wattanawong ◽  
Kanchana Chatchaipaiboon ◽  
Natchanan Sreekirin ◽  
Duangdao Aht-Ong

Bacterial growth on food is a main factor in the reduction of food quality, leading to short-term food shelf life. Development of antibacterial packaging can inhibit the bacterial growth and extend food shelf life. Silver loaded zeolite was used as the antibacterial agent in this work. Three zeolites (different Si/Al ratio) such as zeolite A, zeolite Y, and zeolite Socony Mobil-5 (ZSM-5) incorporating with the same silver content were prepared. The characterization was carried out by energy dispersive X-ray spectroscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, nitrogen adsorption, and color analysis. Antibacterial activity of the three silver zeolites was tested against Escherichia coli and Staphylococcus aureus. Silver loaded zeolite ZSM-5 showed better bacterial inhibition than silver incorporated zeolite A and Y. For composite film preparation, silver loaded zeolite ZSM-5/poly(butylene succinate) composite films were prepared by varying silver loaded zeolite ZSM-5 concentrations and characterized by different techniques (mechanical test, scanning electron microscopy, and color analysis). Poly(butylene succinate) composite films filled with silver loaded zeolite ZSM-5 showed 99.9% of bacterial reduction within 24 h, indicating the effective antibacterial activity. From the silver migration results, the silver release from poly(butylene succinate) films was less than the limitation of European Food Safety Authority regulation, indicating the safety for food packaging applications.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


Author(s):  
M. L. Zimny ◽  
A. C. Haller

During hibernation the ground squirrel is immobile, body temperature reduced and metabolism depressed. Hibernation has been shown to affect dental tissues varying degrees, although not much work has been done in this area. In limited studies, it has been shown that hibernation results in (1) mobilization of bone minerals; (2) deficient dentinogenesis and degeneration of alveolar bone; (3) presence of calculus and tears in the cementum; and (4) aggrevation of caries and pulpal and apical tooth abscesses. The purpose of this investigation was to study the effects of hibernation on dental tissues employing scanning electron microscopy (SEM) and related x-ray analyses.


Author(s):  
Yun Lu ◽  
David C. Joy

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.


Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).


Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.


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