Surface Characterization of Silver and Fe3O4Nanoparticles Incorporated into Collagen-based Scaffolds as Biomaterials for Tissue Regeneration: State-of-the-Art and Future Perspectives

Author(s):  
Abhishek Mandal ◽  
N. Chandrasekaran ◽  
Amitava Mukherjee ◽  
Thothapalli P. Sastry
2019 ◽  
Vol 36 (1) ◽  
pp. 16-37
Author(s):  
Micaela Vannini ◽  
Paola Marchese ◽  
Annamaria Celli ◽  
Cesare Lorenzetti

Semiaromatic polyamides belong to a large family of polymers commonly utilized in demanding engineering applications due to a unique set of outstanding mechanical properties as well as in terms of thermal and chemical resistance. Somewhat less understood is the use of certain members of this family in packaging applications such as the manufacturing of films and sheets or thin-walled containers, as well as the motivations and limitations in designing film structures containing them. This article reviews how m-xylylene diamine (MXD)-based polyamides are used in packaging applications. Attention is also given to film manufacturing and criticalities in its processing. Recent developments in MXD-based polyamides for gas barrier applications are also reported, while examining future perspectives in speciality film manufacturing. The new described copolymers based on MXD6 were synthesized by introducing different co-units, like isophthalic acid, 2,6-naphthalenedicarboxylic acid, glutaric acid, oxalic acid or 1,6-hexamethylene diamine. The performed characterization analyses (DMTA, DSC, density and OTR) allowed the polymer structures and properties to be correlated. Introducing 2,6-naphthalenedicarboxylic acid along the MXD6 chain led to the highest Tg (101°C) and density (1.233 g/cm3) and the lowest OTR (0.0035 cm3·cm/m2·day·atm, up to one order of magnitude lower).


Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 158
Author(s):  
Bridget R. Denzer ◽  
Rachel J. Kulchar ◽  
Richard B. Huang ◽  
Jennifer Patterson

With the increased research on supramolecular hydrogels, many spectroscopic, diffraction, microscopic, and rheological techniques have been employed to better understand and characterize the material properties of these hydrogels. Specifically, spectroscopic methods are used to characterize the structure of supramolecular hydrogels on the atomic and molecular scales. Diffraction techniques rely on measurements of crystallinity and help in analyzing the structure of supramolecular hydrogels, whereas microscopy allows researchers to inspect these hydrogels at high resolution and acquire a deeper understanding of the morphology and structure of the materials. Furthermore, mechanical characterization is also important for the application of supramolecular hydrogels in different fields. This can be achieved through atomic force microscopy measurements where a probe interacts with the surface of the material. Additionally, rheological characterization can investigate the stiffness as well as the shear-thinning and self-healing properties of the hydrogels. Further, mechanical and surface characterization can be performed by micro-rheology, dynamic light scattering, and tribology methods, among others. In this review, we highlight state-of-the-art techniques for these different characterization methods, focusing on examples where they have been applied to supramolecular hydrogels, and we also provide future directions for research on the various strategies used to analyze this promising type of material.


2009 ◽  
Vol 255 (19) ◽  
pp. 8286-8292 ◽  
Author(s):  
J. Skopinska-Wisniewska ◽  
A. Sionkowska ◽  
A. Kaminska ◽  
A. Kaznica ◽  
R. Jachimiak ◽  
...  

Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Langmuir ◽  
2008 ◽  
Vol 24 (17) ◽  
pp. 9500-9507 ◽  
Author(s):  
Claudia Kolbeck ◽  
Manuela Killian ◽  
Florian Maier ◽  
Natalia Paape ◽  
Peter Wasserscheid ◽  
...  

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