scholarly journals Tailored cellulose nanocrystals as a functional ultraviolet absorbing nanofiller of epoxy polymers

2019 ◽  
Vol 1 (7) ◽  
pp. 2612-2623 ◽  
Author(s):  
Prachiben Panchal ◽  
Tizazu H. Mekonnen
Keyword(s):  
Structural Stability ◽  
Cellulose Nanocrystals ◽  
Epoxy Composites ◽  
Uv Exposure ◽  
Uv Filter ◽  
Epoxy Polymers

Epoxy composites filled with UV filter decorated CNCs displayed remarkable structural stability and less discoloration under UV exposure.

scholarly journals Theoretical study of cellulose II nanocrystals with different exposed facets

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Can Leng ◽  
Kenli Li ◽  
Zean Tian ◽  
Yubing Si ◽  
Huang Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bond ◽  
Physicochemical Properties ◽  
Structural Stability ◽  
Cellulose Nanocrystals ◽  
Theoretical Study ◽  
Cellulose Ii ◽  
Natural Polymer ◽  
Contact Sites ◽  
Exposed Facets

AbstractDerived from the most abundant natural polymer, cellulose nanocrystal materials have attracted attention in recent decades due to their chemical and mechanical properties. However, still unclear is the influence of different exposed facets of the cellulose nanocrystals on the physicochemical properties. Herein, we first designed cellulose II nanocrystals with different exposed facets, the hydroxymethyl conformations distribution, hydrogen bond (HB) analysis, as well as the relative structural stability of these models (including crystal facets {A, B, O} and Type-A models vary in size) are theoretically investigated. The results reveal that the HB network of terminal anhydroglucose depends on the adjacent chain’s contact sites in nanocrystals exposed with different facets. Compared to nanocrystals exposed with inclined facet, these exposed with flat facet tend to be the most stable. Therefore, the strategy of tuning exposed crystal facets will guide the design of novel cellulose nanocrystals with various physicochemical properties.

Mechanical and thermal properties of waterborne epoxy composites containing cellulose nanocrystals

Polymer ◽  
2013 ◽  
Vol 54 (24) ◽  
pp. 6589-6598 ◽  
Author(s):  
Shanhong Xu ◽  
Natalie Girouard ◽  
Gregory Schueneman ◽  
Meisha L. Shofner ◽  
J. Carson Meredith
Keyword(s):  
Thermal Properties ◽  
Cellulose Nanocrystals ◽  
Epoxy Composites ◽  
Mechanical And Thermal Properties ◽  
Waterborne Epoxy

scholarly journals Theoretical Study of Cellulose II Nanocrystals with Different Exposed Facets

2021 ◽  
Author(s):  
Can Leng ◽  
Kenli Li ◽  
Zean Tian ◽  
Yubing Si ◽  
Huang Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bond ◽  
Physicochemical Properties ◽  
Structural Stability ◽  
Cellulose Nanocrystals ◽  
Theoretical Study ◽  
Cellulose Ii ◽  
Natural Polymer ◽  
Contact Sites ◽  
Exposed Facets

Abstract Derived from the most abundant natural polymer, cellulose nanocrystal materials have attracted attention in recent decades due to their chemical and mechanical properties. However, still unclear is the influence of different exposed facets of the cellulose nanocrystals on the physicochemical properties. Herein, we first design cellulose II nanocrystals with different exposed facets, the hydroxymethyl conformations distribution, hydrogen bond (HB) analysis, as well as the relative structural stability of these models (including crystal facets {A, B, O} and Type-A models vary in size) are theoretically investigated. The results reveal that the HB network of terminal anhydroglucose depends on the adjacent chain’s contact sites in nanocrystals exposed with different facets. Compared to nanocrystals exposed with inclined facet, these exposed with flat facet tend to be the most stable. Therefore, the strategy of tuning exposed crystal facets will guide the design of novel cellulose nanocrystals with various physicochemical properties.

scholarly journals Thermal Stability and Flammability of Epoxy Composites Filled with Multi-Walled Carbon Nanotubes, Boric Acid, and Sodium Bicarbonate

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 638
Author(s):  
Olga B. Nazarenko ◽  
Yulia A. Amelkovich ◽  
Alexander G. Bannov ◽  
Irina S. Berdyugina ◽  
Visakh P. Maniyan
Keyword(s):  
Carbon Nanotubes ◽  
Sodium Bicarbonate ◽  
Boric Acid ◽  
Hardness Test ◽  
Epoxy Composites ◽  
Thermooxidative Stability ◽  
Epoxy Polymers ◽  
Thermooxidative Destruction ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Epoxy composites filled with 0.5 wt% of multi-walled carbon nanotubes (MWCNTs), 10 and 15 wt% of boric acid and sodium bicarbonate separately, as well as composites filled with a combination of MWCNTs-boric acid and MWCNTs-sodium bicarbonate were prepared. The thermal behavior of the prepared samples was investigated under heating in oxidative environment using thermogravimetric analysis. The hardness was measured using the Shore D hardness test. To evaluate the flammability of the samples, the ignition temperature and time-to-ignition were determined. It was concluded that sodium bicarbonate in the studied concentrations (10 and 15 wt%) is not appropriate for use as a filler capable of improving the thermooxidative stability and reducing the flammability of epoxy polymers. The improvement in the thermal properties can be achieved by using the combination of boric acid and multi-walled carbon nanotubes as fillers. The thermooxidative destruction of the samples filled with boric acid passes more slowly and more evenly via the formation of B2O3 as a result of its decomposition.

Time-resolved high-resolution electron microscopy of structural stability in mgo clusters

1996 ◽  
Vol 54 ◽  
pp. 672-673
Author(s):  
T. Kizuka ◽  
N. Tanaka
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Magnesium Oxide ◽  
Structural Stability ◽  
High Resolution Electron Microscopy ◽  
Video Tape ◽  
Solid State Physics ◽  
Time Resolved ◽  
Resolution Electron ◽  
Structural And Functional Properties

Structure and stability of atomic clusters have been studied by time-resolved high-resolution electron microscopy (TRHREM). Typical examples are observations of structural fluctuation in gold (Au) clusters supported on silicon oxide films, graphtized carbon films and magnesium oxide (MgO) films. All the observations have been performed on the clusters consisted of single metal element. Structural stability of ceramics clusters, such as metal-oxide, metal-nitride and metal-carbide clusters, has not been observed by TRHREM although the clusters show anomalous structural and functional properties concerning to solid state physics and materials science.In the present study, the behavior of ceramic, magnesium oxide (MgO) clusters is for the first time observed by TRHREM at 1/60 s time resolution and at atomic resolution down to 0.2 nm.MgO and gold were subsequently deposited on sodium chloride (001) substrates. The specimens, single crystalline MgO films on which Au particles were dispersed were separated in distilled water and observed by using a 200-kV high-resolution electron microscope (JEOL, JEM2010) equipped with a high sensitive TV camera and a video tape recorder system.

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