Synergistic improvement for mechanical, thermal and optical properties of PVA-co-PE nanofiber/epoxy composites with cellulose nanocrystals

2020 ◽  
Vol 188 ◽  
pp. 107990 ◽  
Author(s):  
Mufang Li ◽  
Xu Zhao ◽  
Yingying Li ◽  
Wen Wang ◽  
Weibing Zhong ◽  
...  
Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2564
Author(s):  
Amparo López-Rubio ◽  
Adriana Blanco-Padilla ◽  
Kristiina Oksman ◽  
Sandra Mendoza

In this work, two different strategies for the development of amaranth protein isolate (API)-based films were evaluated. In the first strategy, ultrathin films were produced through spin-coating nanolayering, and the effects of protein concentration in the spin coating solution, rotational speed, and number of layers deposited on the properties of the films were evaluated. In the second strategy, cellulose nanocrystals (CNCs) were incorporated through a casting methodology. The morphology, optical properties, and moisture affinity of the films (water contact angle, solubility, water content) were characterized. Both strategies resulted in homogeneous films with good optical properties, decreased hydrophilic character (as deduced from the contact angle measurements and solubility), and improved mechanical properties when compared with the neat API-films. However, both the processing method and film thickness influenced the final properties of the films, being the ones processed through spin coating more transparent, less hydrophilic, and less water-soluble. Incorporation of CNCs above 10% increased hydrophobicity, decreasing the water solubility of the API films and significantly enhancing material toughness.


ACS Nano ◽  
2020 ◽  
Vol 14 (8) ◽  
pp. 9440-9448 ◽  
Author(s):  
Tianxing Chen ◽  
Qinglan Zhao ◽  
Xin Meng ◽  
Yao Li ◽  
Hui Peng ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jose Luis Orellana ◽  
Derek Wichhart ◽  
Christopher L. Kitchens

The addition of surface-modified cellulose nanocrystals (CNCs) to polymeric matrices can lead to an enhancement of the mechanical and optical properties of host polymers. The use of surfactants can provide an easy and effective way to change the CNC functionality and to evaluate the effects of surface chemistry in the reinforcement mechanisms. In this work, CNCs were solution blended with polylactic acid (PLA) and melt extruded into films. The PLA toughness increased from 1.70 MJ/m3to 2.74 MJ/m3, a 61% increase, with the addition of 1% of decylamine-modified CNCs without a decrease of the tensile strength or modulus. In this work, we investigated the use of two surfactants, decylamine and cetyltrimethylammonium bromide, to enhance CNC compatibility with the hydrophobic PLA matrix. Decylamine at 1.0 wt.% with respect to CNC loading was found to significantly enhance CNC compatibility and property enhancement. The low concentration of surfactant is notable, as other works typically use significantly higher loadings for CNC incorporation and property enhancement. At high CNC concentrations, mechanical properties decreased but the aligned assembly of the CNCs provided intricate colors to the films when observed between crossed polars. The alignment and nanoscale structure of CNCs within the films play an important role in the properties obtained.


2019 ◽  
Vol 1 (7) ◽  
pp. 2612-2623 ◽  
Author(s):  
Prachiben Panchal ◽  
Tizazu H. Mekonnen

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


2020 ◽  
Vol 11 (4) ◽  
pp. 11797-11816

Cellulose nanomaterials are one of the most relevant scientific-technological discoveries in recent years. Cellulose nanocrystals (CNCs) stand out among them because their extraordinary chemical, mechanical, thermal, and optical properties make them an interesting alternative to manufacture advanced materials from the most abundant biopolymer on Earth. This work presents a critical analysis of the literature published in the last years, emphasizing the various obtaining processes that have emerged in the search for greener methods. A comparative table of the processes used in the extraction of CNCs from various sources (non-edible biomass and agro-industrial wastes) is included, indicating the process’s effectiveness and the characteristics and applications of this sustainable advanced bionanomaterial.


1991 ◽  
Vol 13 (5) ◽  
pp. 115-121 ◽  
Author(s):  
Zhou Qifa ◽  
Zhou Qing ◽  
Li Yiongxiang ◽  
Zhang Liangying ◽  
Yao Xi

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