scholarly journals Characterization of Collagen/Beta Glucan Hydrogels Crosslinked with Tannic Acid

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3412
Author(s):  
Marta Michalska-Sionkowska ◽  
Oliwia Warżyńska ◽  
Beata Kaczmarek-Szczepańska ◽  
Krzysztof Łukowicz ◽  
Anna Maria Osyczka ◽  
...  

Hydrogels based on collagen/β-glucan crosslinked with tannic acid were obtained by neutralization using dialysis. The presence of tannic acid allowed obtaining stable hydrogel materials with better mechanical properties. Tannic acid was released from matrices gradually and not rapidly. The antioxidant properties of the obtained hydrogels increased over the course of their incubation in culture media and were dependent on the concentration of tannic acid in the matrices. The obtained materials influenced dehydrogenase activity and the ATP level of pathogens. Additionally, the materials’ extracts improved the HaCaT cells’ viability. Therefore, the obtained hydrogels seem to be promising biocompatible materials which display antimicrobial properties.

2019 ◽  
Vol 120 ◽  
pp. 748-755 ◽  
Author(s):  
Ruyi Li ◽  
Zicong Zeng ◽  
Guiming Fu ◽  
Yin Wan ◽  
Chengmei Liu ◽  
...  

2021 ◽  
Vol 7 (2) ◽  
pp. 79-85
Author(s):  
Adriana Yazik ◽  
Nur Azira Tukiran

Packaging is a critical process in the food industry because it is used to prevent spoilage, extend shelf-life, and provide an attractive presentation of the food product. Plastic packaging is used all over the world, and its production is increasing year after year. It comes in a variety of colours and designs. However, it has caused serious environmental problems, particularly to the ocean that has become a place for discarded plastic packaging. To address this issue, biodegradable packaging was developed to replace the use of plastic packaging because it helps to reduce environmental impact and waste management costs. Biodegradable packaging is also known as environmentally friendly packaging because it can be degraded into carbon dioxide, water, inorganic compounds, and biomass by microorganisms, algae, fungi, as well as enzyme catalysts. Biodegradable biocomposite film such as starch, cellulose, chitosan, and polyvinyl alcohol (PVA) is required to produce biodegradable packaging. Therefore, this paper aims to characterize PVA as a biocomposite film in biodegradable packaging. PVA has excellent properties to form films, as well as biodegradable, abundant in the environment, and cost-effective. However, it has some limitations in terms of thickness and mechanical properties; thus, the incorporation of PVA with essential oils and fiber is required to improve its mechanical properties, thickness, and provide antimicrobial properties to the packaging. 


Author(s):  
Gyeung Ho Kim ◽  
Mehmet Sarikaya ◽  
D. L. Milius ◽  
I. A. Aksay

Cermets are designed to optimize the mechanical properties of ceramics (hard and strong component) and metals (ductile and tough component) into one system. However, the processing of such systems is a problem in obtaining fully dense composite without deleterious reaction products. In the lightweight (2.65 g/cc) B4C-Al cermet, many of the processing problems have been circumvented. It is now possible to process fully dense B4C-Al cermet with tailored microstructures and achieve unique combination of mechanical properties (fracture strength of over 600 MPa and fracture toughness of 12 MPa-m1/2). In this paper, microstructure and fractography of B4C-Al cermets, tested under dynamic and static loading conditions, are described.The cermet is prepared by infiltration of Al at 1150°C into partially sintered B4C compact under vacuum to full density. Fracture surface replicas were prepared by using cellulose acetate and thin-film carbon deposition. Samples were observed with a Philips 3000 at 100 kV.


Author(s):  
K.L. More ◽  
R.A. Lowden

The mechanical properties of fiber-reinforced composites are directly related to the nature of the fiber-matrix bond. Fracture toughness is improved when debonding, crack deflection, and fiber pull-out occur which in turn depend on a weak interfacial bond. The interfacial characteristics of fiber-reinforced ceramics can be altered by applying thin coatings to the fibers prior to composite fabrication. In a previous study, Lowden and co-workers coated Nicalon fibers (Nippon Carbon Company) with silicon and carbon prior to chemical vapor infiltration with SiC and determined the influence of interfacial frictional stress on fracture phenomena. They found that the silicon-coated Nicalon fiber-reinforced SiC had low flexure strengths and brittle fracture whereas the composites containing carbon coated fibers exhibited improved strength and fracture toughness. In this study, coatings of boron or BN were applied to Nicalon fibers via chemical vapor deposition (CVD) and the fibers were subsequently incorporated in a SiC matrix. The fiber-matrix interfaces were characterized using transmission and scanning electron microscopy (TEM and SEM). Mechanical properties were determined and compared to those obtained for uncoated Nicalon fiber-reinforced SiC.


Author(s):  
Thais Helena Sydenstricker Flores-Sahagun ◽  
Kelly Priscila Agapito ◽  
ROSA MARIA JIMENEZ AMEZCUA ◽  
Felipe Jedyn

Author(s):  
Nicholas Randall ◽  
Rahul Premachandran Nair

Abstract With the growing complexity of integrated circuits (IC) comes the issue of quality control during the manufacturing process. In order to avoid late realization of design flaws which could be very expensive, the characterization of the mechanical properties of the IC components needs to be carried out in a more efficient and standardized manner. The effects of changes in the manufacturing process and materials used on the functioning and reliability of the final device also need to be addressed. Initial work on accurately determining several key mechanical properties of bonding pads, solder bumps and coatings using a combination of different methods and equipment has been summarized.


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