scholarly journals Encapsulation of Fatty Oils into Electrospun Nanofibers for Cosmetic Products with Antioxidant Activity

2019 ◽  
Vol 9 (15) ◽  
pp. 2955 ◽  
Author(s):  
Aleksandra Miletić ◽  
Branimir Pavlić ◽  
Ivan Ristić ◽  
Zoran Zeković ◽  
Branka Pilić
Keyword(s):  
Mechanical Properties ◽  
Antioxidant Activity ◽  
Chemical Properties ◽  
Electrospun Nanofibers ◽  
Functional Materials ◽  
Electrospinning Technique ◽  
Active Compounds ◽  
Good Material ◽  
Physical And Chemical ◽  
And Chemical Properties

Active compounds derived from pomegranate and sea-buckthorn were encapsulated into polylactide (PLA-based fibers) and poly(vinyl-pirrolidone) (PVP-based fibers) nanofibers using electrospinning technique. The focus was on the antioxidant activity of prepared nonwovens. Morphology, thermal, and mechanical properties were also examined. Due to the different physical and chemical properties of the basic polymers, the obtained results indicate that PLA-based fibers have better antioxidant activity than PVP-based ones. All prepared samples were formed from bead-less continuous fibers networks, but in the case of PLA-based samples some small irregularities in the structure occurred. Mechanical properties were improved with the addition of active compounds in most of the cases, while thermal properties were slightly affected. Preserved antioxidant activity of active compounds by encapsulation and good material properties significant for manipulation, make these functional materials promising candidates for application in cosmetics.

Study of Whiskers to be Used in Composite Materials

2021 ◽  
Vol 316 ◽  
pp. 51-55
Author(s):  
Tamara I. Shishelova ◽  
Vadim V. Fedchishin ◽  
Mikhail A. Khramovskih
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Chemical Properties ◽  
High Strength ◽  
Rapid Expansion ◽  
Physical And Chemical Properties ◽  
Reinforcement Fiber ◽  
Object Of Study ◽  
Physical And Chemical ◽  
And Chemical Properties

Rapid expansion of technologies poses higher requirements to structural materials and items made of them. Conventional materials are being replaced by composite materials (composites). Different additives enhancing the properties of initial materials are used as reinforcement fibers of composites. Utilization of micro-and nanosize particles for production of present-day materials is paid much attention to. Whiskers are among such materials. These crystals have high strength, high chemical and temperature resistance. But for rational utilization of whickers of different chemical composition in composite materials one should know their physical and chemical properties. Objectives of the paper: to study physical and chemical properties of whiskers in different compounds, their composition and structure; to prove experimentally the feasibility of utilizing whiskers as a reinforcement fiber of composite materials. Object of study: specimens of whiskers of silicon nitride (Si3N4), aluminum oxide (Al2O3), aluminum nitride (AlN), and mullite (Al6Si2O13). Methods of investigation: thermal study of specimens, study of mechanical properties and chemical strength, and IR-spectroscopy. Results of study: specimens of whiskers have been studied and their mechanical properties have been tabulated for comparison. Extensive thermal investigation was followed by deduction of regularities and identification of chemical properties of whiskers. IR-spectra of whiskers have been studied and conclusions on molecular composition and on presence of impurities in some whiskers have been made.

scholarly journals Biocompatible Material from Indonesian Natural Resource of Wild Silkmoth Cocoon

2018 ◽  
Vol 1 (2) ◽  
pp. 47
Author(s):  
Tjokorda Gde Tirta Nindhia ◽  
Zdenek Knejzlík ◽  
Tomáš Ruml ◽  
I Wayan Surata ◽  
Tjokorda Sari Nindhia
Keyword(s):  
Mechanical Properties ◽  
Natural Resource ◽  
Chemical Properties ◽  
Hot Water ◽  
Physical And Chemical Properties ◽  
Living Things ◽  
Biocompatibility Testing ◽  
Good Biocompatibility ◽  
Physical And Chemical ◽  
And Chemical Properties

Silk can be produced by spider or insect and have prospect as biomaterial for regenerative healing in medical treatment. Silk having physical and chemical properties that support biocompatibility in the living things..In this research, silk that was obtained from Indonesia natural resource of Attacus atlas silkmoth was explored and then will be  developed for biocompatible biomaterial. The treatment with NaOH was developed to separate the fiber from the cocoon. The obtained fiber is investigated its mechanical property by performing tensile test for single fiber. The biocompatibility testing was conducted with human cell (osteosarccoma) cultivation. The result identify that separation by using NaOH yield better better mechanical properties comparing konvenstional method with boiling in hot water. Biocompatibility testing indicate that the the fiber having good biocompatibility.

Influence of Fluidized Fly Ash on the Selected Physical-Mechanical Properties of the Autoclaved Aerated Concrete

2014 ◽  
Vol 899 ◽  
pp. 409-414 ◽  
Author(s):  
Alena Struhárová ◽  
Stanislav Unčík ◽  
Svetozár Balkovic ◽  
Mária Hlavinková
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Amorphous Phases ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Free Cao ◽  
Physical And Chemical ◽  
And Chemical Properties

Fluidized fly ash has different physical and chemical properties compared to fly ash emerging from classic combustion. It contains amorphous phases resulting from a dehydration of clay minerals as well as unreacted sorbent of CaCO3, free CaO and anhydrite (CaSO4). Work targets the possibilities of production of an autoclaved aerated concrete (AAC) from fluidized fly ash, and its influence on particular physical-mechanical properties of autoclaved aerated concrete.

scholarly journals Effect of Copper (II) Sulfate on the Properties of Urea Formaldehyde Adhesive

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 94
Author(s):  
Hui Zhao ◽  
Xianzhen Li ◽  
Xi Wang ◽  
Mianwu Meng ◽  
Xiujian Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Urea Formaldehyde ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Sulfate Content ◽  
Formaldehyde Release ◽  
Uf Resin ◽  
Effect Of Copper ◽  
Physical And Chemical ◽  
And Chemical Properties

The purpose of this work is to investigate the effects of copper (II) sulfate on formaldehyde release and the mechanical properties of urea formaldehyde (UF) adhesive. Copper (II) sulfate has been used as a formaldehyde scavenger in UF resin, and its effects on the physical and chemical properties of UF adhesive have been studied. Moreover, the mechanical properties and formaldehyde release of plywood prepared with modified UF resin have been determined. The UF resin has been characterized by Fourier-transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). FTIR spectra showed that the addition of copper (II) sulfate to the UF resin did not affect the infrared (IR) absorptions of its functional groups, implying that the structure of UF was not modified. Further results showed that: the free formaldehyde content of the UF resin by the incorporation of 3% copper (II) sulfate was 0.13 wt.%, around 71% lower than that of the control UF adhesive. With a copper (II) sulfate content of 3%, the formaldehyde release from treated plywood was 0.74 mg·L−1, around 50% lower than that from the control UF adhesive, and the bonding strength reached 1.73 MPa, around 43% higher than that of the control UF adhesive.

scholarly journals Comparative Analysis of Structure and Properties of Stereoscopic Cocoon and Flat Cocoon

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bin Zhou ◽  
Huiling Wang ◽  
Hongtao Zhou ◽  
Ke Wang ◽  
Shudong Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Properties ◽  
Morphological Characteristics ◽  
Morphological Structure ◽  
Variable Structure ◽  
Fiber Fineness ◽  
The Common ◽  
Physical And Chemical ◽  
Structure And Functions ◽  
And Chemical Properties

Abstract Cocoon is a kind of natural biopolymer material with reasonable structure and various functions. However, its structure and functions are often destroyed in practical application. In this study, we took common Bombyx Mori as the research object, and provided different cocooning sites for single or multiple silkworms to construct common stereoscopic cocoons (“normal cocoons” [NC]) and flat cocoons (“single-silkworm flat cocoons” [SFC] and “multi-silkworm flat cocoons” [MFC]), respectively, and compared the morphological structure and basic properties of these cocoons. The study found that the flat cocoons have similar multi-layered variable structure and characteristics compared to those of the common cocoons; also, morphological characteristics and physical and chemical properties of silk fiber from outer layer to inner layer, such as sericin content, fiber fineness, and change rule of basic mechanical properties, are completely consistent with those of the common cocoons. It can be considered that the flat cocoons are constructed by silkworms in the same “procedural” process as that of common cocoons. Due to the expansion of cocooning space, the mechanical properties of fibers are significantly improved. By controlling the size of the cocooning space or the quantity of silkworms cocooning simultaneously, and the time of spinning, a cocoon material with controllable thickness, weight per square meter, porosity, and number of cocoon layers can be obtained as a composite material for direct application.

scholarly journals Investigate the mechanical properties of Si/Ge (Ge/Si) core-shell nanowires: A molecular dynamics study

2020 ◽  
Vol 3 (4) ◽  
pp. first
Author(s):  
Vuong Van Thanh ◽  
Tran The Quang ◽  
Nguyen Tuan Hung ◽  
Vu Le Huy ◽  
Do Van Truong
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Elastic Modulus ◽  
Lattice Mismatch ◽  
Chemical Properties ◽  
Core Shell ◽  
The Core ◽  
Axial Tensile ◽  
Physical And Chemical ◽  
And Chemical Properties

Nanowires (NWs) have been used increasingly in practice due to their outstanding mechanical, physical, and chemical properties. In this paper, we use the molecular dynamics (MD) method to investigate the mechanical properties of NWs (Si/Ge, Ge/Si) with a core-shell structure under the axial tensile strain along the <100>/{100} direction. Our results show that the strength and elastic modulus of Ge/Si and Si/Ge NWs depend on the composition and size of the core/shell crosssection. The strength and strain of Ge/Si NW decrease with increasing the size of the core crosssection because of the lattice mismatch between two layers of core/shell materials. The elastic modulus of Ge/Si NWs increases with the increasing the size of the core cross-section, while the elastic modulus of the Si/Ge NW decreases. In addition, the theoretical strength and elastic modulus of Ge/Si NWs reduce with the growth of the temperature. Furthermore, we also investigate the effect of strain rate on the mechanical properties of the Ge/Si NWs. The obtained results of the study provide the intrinsic properties of the core-shell NWs and also help in the design and fabrication of electronic and optical devices based on the Ge/Si NWs.

BIOMEDICAL APPLICATIONS OF ELECTROSPUN NANOFIBERS

2020 ◽  
Vol 27 (11) ◽  
pp. 2030001
Author(s):  
ZHANG YANCONG ◽  
DOU LINBO ◽  
MA NING ◽  
WU FUHUA ◽  
NIU JINCHENG
Keyword(s):  
Biomedical Applications ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Electrospun Nanofibers ◽  
High Porosity ◽  
Nanofiber Diameter ◽  
Surface Microscopy ◽  
Different Shapes ◽  
Physical And Chemical ◽  
And Chemical Properties

Electrospun technology is a simple and flexible method for preparation of nanofiber materials with unique physical and chemical properties. The nanofiber diameter is adjustable from several nanometers to few microns during the preparation. Electrospun nanofiber materials are easy to be assembled into different shapes of three-dimensional structures. These materials exhibit high porosity and surface area and can simulate the network structures of collagen fibers in a natural extracellular matrix, thereby providing a growth microenvironment for tissue cells. Electrospun nanofibers therefore have extensive application prospects in the biomedicine field, including in aerospace, filtration, biomedical applications, and biotechnology. Nanotechnology has the potential to revolutionize many fields, such as surface microscopy, silicon fabrication, biochemistry, molecular biology, physical chemistry, and computational engineering, while the advent of nanofibers has increased the understanding of nanotechnology among academia, industry, and the general public. This paper mainly introduces the application of nanofiber materials in tissue engineering, drug release, wound dressing, and other biomedicine fields.

Untersuchungen zum Einfluss der thermischen Vorbehandlung auf das Sorptionsverhalten und ausgewählte mechanische Eigenschaften von Fichtenholz | Examinations of the influence of thermal treatment on certain mechanical properties of spruce (reviewed paper)

2005 ◽  
Vol 156 (2) ◽  
pp. 47-51 ◽  
Author(s):  
Fritz Bächle ◽  
Peter Niemz
Keyword(s):  
Mechanical Properties ◽  
Thermal Treatment ◽  
Chemical Properties ◽  
Thermal Treatments ◽  
Physical And Chemical Properties ◽  
Mechanische Eigenschaften ◽  
Physical And Chemical ◽  
And Chemical Properties

A range of mechanical, physical and chemical properties were tested on spruce, which had been subjected to diverse thermal treatments. The results of the examination are presented in tables and graphic figures.

scholarly journals Fruit quality attributes of low chilling requirement ‘Snowchaser’ blueberry cultivated in Brazil

2018 ◽  
Vol 40 (1) ◽  
Author(s):  
Isabela Maria Jimenes ◽  
Simone Rodrigues da Silva ◽  
Jaqueline Visioni Tezotto-Uliana ◽  
Tatiana Cantuarias-Avilés
Keyword(s):  
Antioxidant Activity ◽  
Skin Color ◽  
Chemical Properties ◽  
Storage Period ◽  
Fruit Storage ◽  
Activity Maximum ◽  
Fruit Shelf Life ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract In Brazil there are still few studies on the post-harvest quality of low-chill blueberry cultivars, which have been recently introduced in the country. ‘Snowchaser’ blueberries were evaluated during a six-day storage period regarding fruit physical and chemical properties, and its antioxidant capacity. During fruit storage there was an increased weight loss and maintenance of some skin color properties such as luminosity (L*) and b*, whereas the values of parameter a* decreased and chroma (C) values increased. The levels of anthocyanins and flavonoids in the pulp increased, as well as the antioxidant activity. Maximum fruit shelf life at room temperature was six days without reduction on the antioxidant activity along the period, which is beneficial to consumers’ health.

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