scholarly journals Preparation and Characterization of Electrospun Pectin-Based Films and Their Application in Sustainable Aroma Barrier Multilayer Packaging

2019 ◽  
Vol 9 (23) ◽  
pp. 5136 ◽  
Author(s):  
Busra Akinalan Balik ◽  
Sanem Argin ◽  
Jose M. Lagaron ◽  
Sergio Torres-Giner

Pectin was first dissolved in distilled water and blended with low contents of polyethylene oxide 2000 (PEO2000) as the carrier polymer to produce electrospun fibers. The electrospinning of the water solution of pectin at 9.5 wt% containing 0.5 wt% PEO2000 was selected as it successfully resulted in continuous and non-defected ultrathin fibers with the highest pectin content. However, annealing of the resultant pectin-based fibers, tested at different conditions, developed films with low mechanical integrity, high porosity, and also dark color due to their poor thermal stability. Then, to improve the film-forming process of the electrospun mats, two plasticizers, namely glycerol and polyethylene glycol 900 (PEG900), were added to the selected pectin solution in the 2–3 wt% range. The optimal annealing conditions were found at 150 °C with a pressure of 12 kN load for 1 min when applied to the electrospun pectin mats containing 5 wt% PEO2000 and 30 wt% glycerol and washed previously with dichloromethane. This process led to completely homogenous films with low porosity and high transparency due to a phenomenon of fibers coalescence. Finally, the selected electrospun pectin-based film was applied as an interlayer between two external layers of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by the electrospinning coating technology and the whole structure was annealed to produce a fully bio-based and biodegradable multilayer film with enhanced barrier performance to water vapor and limonene.


Author(s):  
H. M. Kerch ◽  
R. A. Gerhardt

Highly porous ceramics are employed in a variety of engineering applications due to their unique mechanical, optical, and electrical characteristics. In order to achieve proper design and function, information about the pore structure must be obtained. Parameters of importance include pore size, pore volume, and size distribution, as well as pore texture and geometry. A quantitative determination of these features for high porosity materials by a microscopic technique is usually not done because artifacts introduced by either the sample preparation method or the image forming process of the microscope make interpretation difficult.Scanning electron microscopy for both fractured and polished surfaces has been utilized extensively for examining pore structures. However, there is uncertainty in distinguishing between topography and pores for the fractured specimen and sample pullout obscures the true morphology for samples that are polished. In addition, very small pores (nm range) cannot be resolved in the S.E.M. On the other hand, T.E.M. has better resolution but the specimen preparation methods involved such as powder dispersion, ion milling, and chemical etching may incur problems ranging from preferential widening of pores to partial or complete destruction of the pore network.



MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3123-3131
Author(s):  
Mario Flores Nicolas ◽  
Marina Vlasova ◽  
Pedro Antonio Márquez Aguilar ◽  
Mykola Kakazey ◽  
Marcos Mauricio Chávez Cano ◽  
...  

AbstractThe low-temperature synthesis of bricks prepared from high-siliceous clays by the method of plastic molding of blanks was used. For the preparation of brick blanks, binary and ternary mixtures of high-siliceous clays, black sand, and bottle glass cullet were used. Gray-black low-porosity and high-porosity ceramics was obtained by sintering under conditions of oxygen deficiency. It has been established that to initiate plastic in mixtures containing high-siliceous clay, it is necessary to add montmorillonite/bentonite additives, carry out low-temperature sintering, and introduce low-melting glass additives with a melting point ranging from 750 to 800 °C. The performed investigations have shown that the sintering of mixtures with a total content of iron oxide of about 5 wt% under reducing conditions at Tsint. = 800°C for 8 h leads to the formation of glass ceramics consisting of quartz, feldspars, and a phase. The main sources of the appearance of a dark color is the formation of [Fe3+O4]4- and [Fe3+O6]9- anions in the composition of the glass phase and feldspars. By changing the contents of clay, sand, and glass in sintering, it is possible to obtain two types of ceramic materials: (a) in the form of building bricks and (b) in the form of porous fillers.



2012 ◽  
Vol 7 (4) ◽  
Author(s):  
Norikazu Sugaya

This new surface treatment is simple and easy as well as low in cost. The processes can even be performed by hand. Pharmaceutical raw materials used for the surface treatment, such as hydrochloric acid and nitric acid used in a mixed acid washing process and vegetable oil used in an organic film forming process, are easily obtained in many countries.



1987 ◽  
Vol 153 (Part_1_2) ◽  
pp. 27-36 ◽  
Author(s):  
H. Rosenberger ◽  
H. Bürger ◽  
H. Schütz ◽  
G. Scheler ◽  
G. Maenz


1999 ◽  
Vol 587 ◽  
Author(s):  
Kazumasa Narumi ◽  
Shunya Yamamoto ◽  
Hiroshi Naramoto

AbstractsVariation of surface steps on sapphire (0001) and (1120) substrates processed with thermal annealing in air or a reducing environment at 1000 to 1400°C for 1 to 10 hours were investigated with an atomic force microscope (AFM). The annealed (0001) surfaces consist of atomically smooth and large terraces and atomic-height steps, whose configurations strongly depend on annealing conditions. On the (1120) surfaces, where crystallographic misorientation is almost an order of magnitude larger than that of the (0001) surfaces, step height and terraces increase in size with the longer annealing time and higher annealing temperature. Characteristic step figures due to the symmetry of atomic arrangement were observed on the (0001) surface.



2011 ◽  
Vol 415-417 ◽  
pp. 1810-1815 ◽  
Author(s):  
Jian Bing Liu ◽  
Qiang Tang ◽  
Shen Zhou Lu ◽  
Ceng Zhang ◽  
Ming Zhong Li

When the articular cartilage defect accompanies with the subchondral bone defect, using bilayer scaffolds which can integrate with surrounding host cartilage and bone tissue respectively as the tissue engineering scaffolds will be conducive to the repair of tissue defects. This paper reports a new method for preparing bilayer scaffolds. Firstly, hydroxyapatite (HA)/silk fibroin(SF) composite porous materials which have high porosity were prepared by a isostatic compaction molding method, then it was fully immersed in silk fibroin solution, and finally SF/HA bilayer scaffolds were obtained by freeze-drying. The structure of the bilayer scaffolds were investigated through scanning electron microscopy, X-ray diffraction, Fourier transform-infrared spectroscopy, electron excitation spectroscopy and electron microprobe. The results indicated that the upper layer of SF/HA bilayer scaffolds is porous SF component, the under layer is the porous HA/SF composite component and the interface of the two layer is closely connected. Furthermore, mesenchymal stem cells from mouse bone marrow were seeded into the bilayer scaffolds and the results showed that the cells had a well adhesion and growth after culturing for 3 days.



2014 ◽  
Vol 8 (2) ◽  
pp. 81-85 ◽  
Author(s):  
Marija Prekajski ◽  
Biljana Babic ◽  
Dusan Bucevac ◽  
Jelena Pantic ◽  
Jelena Gulicovski ◽  
...  

A new technology based on bio-templating approach was proposed in this paper. Egg-shell membrane (ESM) has been employed as a natural biotemplate. Fibrous oxide ceramics was prepared by wet impregnation of biological template with water solution of cerium nitrate. The template was derived from membranes of fresh chicken eggs. Repeated impregnation, pyrolysis and final calcination in the range of 600 to 1200?C in air resulted in template burnout and consolidation of the oxide layers. At low temperatures, the obtained products had structure which corresponded to the negative replication of biological templates. Unique bio-morphic CeO2 microstructures with interwoven networks were synthesized and characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD), whereas low-temperature nitrogen adsorption (BET) method was used in order to characterize porous properties.



2018 ◽  
Vol 941 ◽  
pp. 21-26
Author(s):  
Gloria Basanta ◽  
Ana L. Rivas ◽  
Ervis Díaz ◽  
Carlos Parra

The present work has been undertaken to assess the evolution of dissolution process of large dendritic precipitates in a V-Nb-Ti microalloyed steel. The study was performed by reheating the samples at 1250°C, simulating the industrial reheating practices at laboratory scale and in situ, following industrial profile; afterwards the samples were quenched in 10%NaCl aqueous solution. The characterization of the material was carried out by scanning electron microscopy accompanied with dispersive energy spectrometry, and chemical analysis by inductively coupled plasma optical emission spectrometry. The results showed a partial dissolution of dendritic precipitates. This process ocurred by a progressive dissolving the Nb-rich shells formed over cuboidal particles and primary arm of well-faceted dendritic precipitates, and by fragmentation and spheroidization of secondary branches. These processes gave rise to spherical Nb rich precipitates and cuboidal particles at the reheating conditions used in this study. Both type of particles contain vanadium.



Food Research ◽  
2020 ◽  
Vol 4 (6) ◽  
pp. 1937-1946
Author(s):  
M.M.D.R. Tugay ◽  
L.E. Mopera ◽  
E.B. Esguerra ◽  
K.A.T. Castillo-Israel

This study aimed to characterize and compare pili (Canarium ovatum Engl.) pulp oil from two different varieties of pili fruits in Bicol, Philippines namely M. Orolfo and Orbase varieties for possible utilization into oil-based products. The effects of varietal differences in pili fruits on physical, chemical and quality characteristics of its pulp oil were determined. These two oils were also compared with control oils, commercially available coconut oil and extra virgin olive oil. Pili pulp oil from M. Orolfo had dark color while Orbase had color close to extra virgin olive oil. The two varieties did not significantly differ from each other in terms of refractive index, moisture and volatile matters, acid value, iodine value, saponification number and percent unsaponifiable matter but significantly differed from coconut oil and extra virgin olive oil. On the other hand, the two varieties significantly differed from each other in terms of peroxide value, Vitamin A and α-tocopherol contents. In terms of fatty acid profile, high amounts of palmitic acid were determined in both pili varieties (19-25%) compared with coconut oil (6.34%). Oleic acid in Orbase was 71.5% while M. Orolfo had 58.1%, which are comparable with extra virgin olive oil (77.9%). Pili pulp oils from M. Orolfo and Orbase can be utilized into oilbased products because its chemical and quality characteristics are within the standard. Both can be stored for a longer period of time and healthier in terms of fatty acid composition and natural antioxidant content.



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