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.

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.

Rod- and sphere-shaped cellulose nanocrystals (CNCs) type-II derived from Asclepias Syriaca stem residues: Composition, Morphology and Thermal properties.

2020 ◽  
Author(s):  
Jérémy Astruc ◽  
Michel Grandbois ◽  
Gaétan Laroche ◽  
Mathieu Robert ◽  
Said Elkoun
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Cellulose Nanocrystals ◽  
Cellulose Content ◽  
Cellulose Ii ◽  
Type Ii ◽  
Cellulose I ◽  
Asclepias Syriaca ◽  
Force Microscopy ◽  
Atomic Force

Cellulose nanocrystals or nanoparticles (CNCs) has drawn a lot of attention due to their abundance, biocompatibility, renewability and their excellent mechanical properties paving the way to innovative and sustainable applications. In the present work, the stem residues of Asclepias Syriaca, better known as milkweed and generally regarded as a weed, was used for the first time to extract CNCs with a crystalline structure type-II (CNCs-II). Structural, thermal, morphological and mechanical properties of extracted CNCs-II were characterized by means of Fourier Transform Infrared (FT-IR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), Thermogravimetric Analysis (TGA) and Atomic Force Microscopy (AFM). Asclepias Syriaca stem fibers revealed quite similar cellulose content as compared to other milkweed species and, stable suspensions made of nanosphere- and nanorod- shape CNCs-II were successfully extracted from raw milkweed fibers. In addition, after conversion from cellulose-I to cellulose-II by mercerization, milkweed cellulose-II exhibited higher thermal resistance as compared to cellulose-I with degradation temperature at 328 °C and 310 °C respectively. Finally, the transversal elastic modulus of individuals CNCs-II, as measured by atomic force microscopy, was found to be in the range of 3.5-27 GPa which is consistent with reported values for CNCs-I or -II in the literature.

scholarly journals Is Dialdehyde Chitosan a Good Substance to Modify Physicochemical Properties of Biopolymeric Materials?

2021 ◽  
Vol 22 (7) ◽  
pp. 3391
Author(s):  
Sylwia Grabska-Zielińska ◽  
Alina Sionkowska ◽  
Ewa Olewnik-Kruszkowska ◽  
Katarzyna Reczyńska ◽  
Elżbieta Pamuła
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Physicochemical Properties ◽  
Silk Fibroin ◽  
Three Dimensional ◽  
Microscopy Imaging ◽  
Maximum Deformation ◽  
One Step ◽  
Chitosan Blends ◽  
Fourier Transfer Infrared Spectroscopy

The aim of this work was to compare physicochemical properties of three dimensional scaffolds based on silk fibroin, collagen and chitosan blends, cross-linked with dialdehyde starch (DAS) and dialdehyde chitosan (DAC). DAS was commercially available, while DAC was obtained by one-step synthesis. Structure and physicochemical properties of the materials were characterized using Fourier transfer infrared spectroscopy with attenuated total reflectance device (FTIR-ATR), swelling behavior and water content measurements, porosity and density observations, scanning electron microscopy imaging (SEM), mechanical properties evaluation and thermogravimetric analysis. Metabolic activity with AlamarBlue assay and live/dead fluorescence staining were performed to evaluate the cytocompatibility of the obtained materials with MG-63 osteoblast-like cells. The results showed that the properties of the scaffolds based on silk fibroin, collagen and chitosan can be modified by chemical cross-linking with DAS and DAC. It was found that DAS and DAC have different influence on the properties of biopolymeric scaffolds. Materials cross-linked with DAS were characterized by higher swelling ability (~4000% for DAS cross-linked materials; ~2500% for DAC cross-linked materials), they had lower density (Coll/CTS/30SF scaffold cross-linked with DAS: 21.8 ± 2.4 g/cm3; cross-linked with DAC: 14.6 ± 0.7 g/cm3) and lower mechanical properties (maximum deformation for DAC cross-linked scaffolds was about 69%; for DAS cross-linked scaffolds it was in the range of 12.67 ± 1.51% and 19.83 ± 1.30%) in comparison to materials cross-linked with DAC. Additionally, scaffolds cross-linked with DAS exhibited higher biocompatibility than those cross-linked with DAC. However, the obtained results showed that both types of scaffolds can provide the support required in regenerative medicine and tissue engineering. The scaffolds presented in the present work can be potentially used in bone tissue engineering to facilitate healing of small bone defects.

Feasible strategies to promote the sensing performances of spinel MCo2O4 (M = Ni, Fe, Mn, Cu and Zn) based electrochemical sensors: A review

2021 ◽  
Author(s):  
Josué M. Gonçalves ◽  
Diego Pessoa Rocha ◽  
Murillo N.T. Silva ◽  
Paulo Roberto Martins ◽  
Edson Nossol ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physicochemical Properties ◽  
Electrochemical Sensors ◽  
Combined Effects ◽  
Cu And Zn

Spinel MCo2O4 (M = Ni, Fe, Mn, Cu and Zn) demonstrates excellent physicochemical properties due to combined effects of M2+ and Co2+ cations. Their inimitable optical, electronic, and mechanical properties...

Synthesis and characterization of photothermal antibacterial hydrogel with enhanced mechanical properties

2021 ◽  
Author(s):  
Shu bin Li ◽  
Xiao Wang ◽  
Jiang Zhu ◽  
Zhenyu Wang ◽  
Lu Wang
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bond ◽  
Fe3o4 Nanoparticles ◽  
Intermolecular Hydrogen Bond ◽  
Amide Bond ◽  
Synthesis And Characterization

In this work, using carboxyl-modified Fe3O4 nanoparticles as a photothermal agent, combining the chemical amide bond and intermolecular hydrogen bond crosslinking force, a photothermal hydrogel with enhanced mechanical properties was...

scholarly journals Effect of cross-linkable bacterial cellulose nanocrystals on the physicochemical properties of silk sericin films

2021 ◽  
Vol 97 ◽  
pp. 107161
Author(s):  
Jeongmin Nam ◽  
Yujin Hyun ◽  
Subin Oh ◽  
Jinseok Park ◽  
Hyoung-Joon Jin ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Bacterial Cellulose ◽  
Cellulose Nanocrystals ◽  
Silk Sericin

scholarly journals Effects of Different Contents of Each Component on the Structural Stability and Mechanical Properties of Co-Cr-Fe-Ni High-Entropy Alloys

2021 ◽  
Vol 11 (6) ◽  
pp. 2832
Author(s):  
Haibo Liu ◽  
Cunlin Xin ◽  
Lei Liu ◽  
Chunqiang Zhuang
Keyword(s):  
Mechanical Properties ◽  
Structural Stability ◽  
High Entropy Alloys ◽  
Face Centered Cubic ◽  
Obvious Effect ◽  
High Entropy ◽  
Precise Control ◽  
Component Content ◽  
Face Centered ◽  
And Performance

The structural stability of high-entropy alloys (HEAs) is closely related to their mechanical properties. The precise control of the component content is a key step toward understanding their structural stability and further determining their mechanical properties. In this study, first-principle calculations were performed to investigate the effects of different contents of each component on the structural stability and mechanical properties of Co-Cr-Fe-Ni HEAs based on the supercell model. Co-Cr-Fe-Ni HEAs were constructed based on a single face-centered cubic (FCC) solid solution. Elemental components have a clear effect on their structure and performance; the Cr and Fe elements have an obvious effect on the structural stability and equilibrium lattice constant, respectively. The Ni elements have an obvious effect on stiffness. The Pugh ratios indicate that Cr and Ni addition may increase ductility, whereas Co and Fe addition may decrease it. With increasing Co and Fe contents or decreasing Cr and Ni contents, the structural stability and stiffness of Co-Cr-Fe-Ni HEAs are improved. The structural stability and mechanical properties may be related to the strength of the metallic bonding and covalent bonding inside Co-Cr-Fe-Ni HEAs, which, in turn, is determined by the change in element content. Our results provide the underlying insights needed to guide the optimization of Co-Cr-Fe-Ni HEAs with excellent mechanical properties.

scholarly journals Enhancing the mechanical properties and cytocompatibility of magnesium potassium phosphate cement by incorporating oxygen-carboxymethyl chitosan

2020 ◽  
Author(s):  
Changtian Gong ◽  
Shuo Fang ◽  
Kezhou Xia ◽  
Jingteng Chen ◽  
Liangyu Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physicochemical Properties ◽  
Bone Cement ◽  
Ph Value ◽  
Setting Time ◽  
Potassium Phosphate ◽  
Carboxymethyl Chitosan ◽  
Bioactive Substances ◽  
Magnesium Potassium Phosphate Cement

Abstract Incorporating bioactive substances into synthetic bioceramic scaffolds is challenging. In this work, oxygen-carboxymethyl chitosan (O-CMC), a natural biopolymer that is nontoxic, biodegradable and biocompatible, was introduced into magnesium potassium phosphate cement (K-struvite) to enhance its mechanical properties and cytocompatibility. This study aimed to develop O-CMC/magnesium potassium phosphate composite bone cement (OMPC), thereby combining the optimum bioactivity of O-CMC with the extraordinary self-setting properties and mechanical intensity of the K-struvite. Our results indicated that O-CMC incorporation increased the compressive strength and setting time of K-struvite and decreased its porosity and pH value. Furthermore, OMPC scaffolds remarkably improved the proliferation, adhesion and osteogenesis related differentiation of MC3T3-E1 cells. Therefore, O-CMC introduced suitable physicochemical properties to K-struvite and enhanced its cytocompatibility for use in bone regeneration.

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