scholarly journals Structural and thermal characterization of different types of cellulosic fibers

BIBECHANA ◽  
2018 ◽  
Vol 16 ◽  
pp. 177-186 ◽  
Author(s):  
Jyoti Giri ◽  
Ralf Lach ◽  
Janak Sapkota ◽  
Md. Abu Bin Hasan Susan ◽  
Jean-Marc Saiter ◽  
...  

Micro- and nanocrystalline cellulose were extracted from wheat stalk (WS) using different thermomechanical and chemical treatments and characterized by spectroscopic, microscopic and diffraction techniques. The virgin WS fibers were found to be structurally quite similar to the commercial microcrystalline cellulose (MCC). Similar to the commercial one, the MCC extracted from the WS possessed intense infrared (IR) peaks whereas those peaks became more broader in the nanocrystalline cellulose (NCC) of the same origin, which can be attributed to possible breakdown of inter- and intramolecular H-bonding due to strong acid treatment of the MCC. Microscopic results revealed characteristic textures of the MCC and the NCC, the MCC being irregular bundles of the primary crystals bound together with the amorphous phase. The latter was found to disintegrate upon acid hydrolysis giving rise to the rod-shaped nanocrystals having much larger surface area and thus possessing more intense hydrophilic character. The MCC was found to be more stable than the NCC which can be attributed to the presence of protective and binding coating provided by the amorphous cellulosic matter.BIBECHANA 16 (2019) 177-186

2017 ◽  
Vol 15 (6) ◽  
pp. 860-869 ◽  
Author(s):  
P. Manimaran ◽  
M. Prithiviraj ◽  
S.S. Saravanakumar ◽  
V.P. Arthanarieswaran ◽  
P. Senthamaraikannan

2020 ◽  
pp. 089270572092512
Author(s):  
Mohammad Y Al-Haik ◽  
Saud Aldajah ◽  
Waseem Siddique ◽  
Mohammad M Kabir ◽  
Yousef Haik

This article addresses the effect of nanocrystalline cellulose (NCC) on the mechanical and thermal properties of polypropylene (PP). A new approach was adopted to produce mechanically improved and thermally stable PP-NCC nanocomposite. This approach involved producing optimized PP-NCC nanocomposite by adding NCC nanoparticles to PP matrix at different concentrations by means of injection molding process. The aim of this work was to find the optimum NCC concentration to enhance the mechanical and thermal properties of the PP matrix. The mechanical and thermal behavior of PP-NCC nanocomposite was studied by performing three-point bend, nanoindentation, differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), scanning electron microscope (SEM), and Fourier transform infrared (FTIR) spectroscopy tests. The results showed that the mechanical properties of strength, modulus, and hardness of the nanocomposites increased with the addition of NCC by 6.5%, 19%, and 150%, respectively. DSC results showed that the addition of NCC to PP does not affect the thermal stability (melting temperature). However, TGA showed that upon inclusion of NCC nanoparticles, the thermal stability of the samples improved compared to pure PP except for the 5% added NCC. This is attributed to the presence of NCC rod-like particles that dissipated heat by generating tortuous paths, as depicted in the SEM results and verified by FTIR results.


Author(s):  
J.B. Posthill ◽  
R.P. Burns ◽  
R.A. Rudder ◽  
Y.H. Lee ◽  
R.J. Markunas ◽  
...  

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.


1999 ◽  
Vol 6 (1) ◽  
pp. 101-108 ◽  
Author(s):  
E. Delacre ◽  
D. Defer ◽  
E. Antczak ◽  
B. Duthoit

2005 ◽  
Vol 125 ◽  
pp. 177-180
Author(s):  
T. Lopez ◽  
M. Picquart ◽  
G. Aguirre ◽  
Y. Freile ◽  
D. H. Aguilar ◽  
...  

2018 ◽  
Vol 1 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Kamaljit Singh Boparai ◽  
Rupinder Singh

This study highlights the thermal characterization of ABS-Graphene blended three dimensional (3D) printed functional prototypes by fused deposition modeling (FDM) process. These functional prototypes have some applications as electro-chemical energy storage devices (EESD). Initially, the suitability of ABS-Graphene composite material for FDM applications has been examined by melt flow index (MFI) test. After establishing MFI, the feedstock filament for FDM has been prepared by an extrusion process. The fabricated filament has been used for printing 3D functional prototypes for printing of in-house EESD. The differential scanning calorimeter (DSC) analysis was conducted to understand the effect on glass transition temperature with the inclusion of Graphene (Gr) particles. It has been observed that the reinforced Gr particles act as a thermal reservoir (sink) and enhances its thermal/electrical conductivity. Also, FT-IR spectra realized the structural changes with the inclusion of Gr in ABS matrix. The results are supported by scanning electron microscopy (SEM) based micrographs for understanding the morphological changes.


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