scholarly journals Cellulose Nanocrystals vs. Cellulose Nanofibers: A Comparative Study of Reinforcing Effects in UV-Cured Vegetable Oil Nanocomposites

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1791
Author(s):  
Anda Barkane ◽  
Edgars Kampe ◽  
Oskars Platnieks ◽  
Sergejs Gaidukovs
Keyword(s):  
Comparative Study ◽  
Vegetable Oil ◽  
Polymer Matrix ◽  
Uv Light ◽  
Structural Characteristics ◽  
Cellulose Nanofibers ◽  
Spectroscopy Analysis ◽  
Thermoset Composites ◽  
Beneficial Effects ◽  
Degradation Temperature

There is an opportunity to use nanocellulose as an efficient renewable reinforcing filler for polymer composites. There have been many investigations to prove the reinforcement concept of different nanocellulose sources for thermoplastic and thermoset polymers. The present comparative study highlighted the beneficial effects of selecting cellulose nanofibers (CNFs) and nanocrystals (CNCs) on the exploitation properties of vegetable oil-based thermoset composite materials —thermal, thermomechanical, and structural characteristics. The proposed UV-light-curable resin consists of an acrylated epoxidized soybean oil polymer matrix and two different nanocellulose reinforcements. High loadings of up to 30 wt% of CNFs and CNCs in irradiation-cured vegetable oil-based thermoset composites were reported. Infrared spectroscopy analysis indicated developed hydrogen-bonding interactions between the nanocellulose and polymer matrix. CNCs yielded a homogeneous nanocrystal dispersion, while CNFs revealed a nanofiber agglomeration in the polymer matrix, as shown by scanning electron microscopy. Thermal degradation showed that nanocellulose reduced the maximum degradation temperature by 5 °C for the 30 wt% CNC and CNF nanocomposites. Above the glass transition temperature at 80 °C, the storage modulus values increased 6-fold and 2-fold for the 30 wt% CNC and CNF nanocomposites, respectively. In addition, the achieved reinforcement efficiency factor r value for CNCs was 8.7, which was significantly higher than that of CNFs of 2.2. The obtained nanocomposites with enhanced properties show great potential for applications such as UV-light-processed coatings, adhesives, and additive manufacturing inks.

Comparative study of paper and nanopaper properties prepared from bacterial cellulose nanofibers and fibers/ground cellulose nanofibers of canola straw

2013 ◽  
Vol 43 ◽  
pp. 732-737 ◽  
Author(s):  
Hossein Yousefi ◽  
Mehdi Faezipour ◽  
Sahab Hedjazi ◽  
Mohammad Mazhari Mousavi ◽  
Yoshio Azusa ◽  
...  
Keyword(s):  
Comparative Study ◽  
Bacterial Cellulose ◽  
Cellulose Nanofibers ◽  
Canola Straw

Application of a Novel Collector DXS in Cassiterite Flotation

2013 ◽  
Vol 826 ◽  
pp. 14-19
Author(s):  
Yi Min Zhu ◽  
Yan Ping Yang ◽  
Wen Dan Wang ◽  
Yan Feng Li ◽  
Duo Zhen Ren ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Infrared Spectroscopy ◽  
Carboxylic Acid ◽  
Comparative Study ◽  
Hydroxamic Acid ◽  
Spectroscopy Analysis ◽  
Adsorption Mechanisms ◽  
Before And After ◽  
The Relationship

A comparative study on the collecting effect to cassiterite was studied using a new carboxylic acid modified collector DXS and traditional collector salicylaldehyde hydroxamic acid as collectors, respectively. In addition, the relationship between floatability of DXS and crystal structure of cassiterite was investigated. By means of infrared spectroscopy analysis of the cassiterite surface before and after adsorbing DXS molecules, the adsorption mechanisms of DXS on the surface of cassiterite were analyzed.Keywords: carboxylic acid modified collector DXS; cassiterite; flotation mechanism

Comparative Study of Mechanical and Tribological Behaviour of Thermoplast-Based Composites

2017 ◽  
pp. 78-98
Author(s):  
Kaushik Kumar ◽  
J. Paulo Davim
Keyword(s):  
Composite Material ◽  
Comparative Study ◽  
Polymer Matrix ◽  
Weight Ratio ◽  
Experimental Results ◽  
Tribological Behaviour ◽  
Environment Friendly ◽  
Short Cycle ◽  
Inorganic Fillers ◽  
Day By Day

The usage of composite material has been increasing day by day over the years due to the excellent properties being offered by them such as lower volume-to-weight ratio, improved toughness, recyclable, environment friendly and also due to their short cycle productivity, easiness in fabrication, long lasting life span etc. This work presents study of mechanical and tribological behaviour of ABS polymer matrix filled with micron-sized inorganic and Natural / Green fillers. The main purpose behind this work is to compare the performance of composites with different class of fillers. The experimental results unveil that the composite with inorganic fillers perform better than with natural based fillers.

scholarly journals Synthesis, Characterization, and Evaluation of Genistein-Loaded Zein/Carboxymethyl Chitosan Nanoparticles with Improved Water Dispersibility, Enhanced Antioxidant Activity, and Controlled Release Property

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1604
Author(s):  
Yu Xiao ◽  
Chi-Tang Ho ◽  
Yulian Chen ◽  
Yuanliang Wang ◽  
Zihao Wei ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Controlled Release ◽  
Water Solubility ◽  
Uv Light ◽  
Chitosan Nanoparticles ◽  
Carboxymethyl Chitosan ◽  
Food Ingredient ◽  
Beneficial Effects ◽  
Release Property ◽  
Water Dispersibility

Genistein is one of major isoflavones derived from soybean products and it is believed to have beneficial effects on human health. However, its low water-solubility and poor oral bioavailability severely hamper its use as a functional food ingredient or for pharmaceutical industry. In this study, zein and zein/carboxymethyl chitosan (CMCS) nanoparticles were prepared to encapsulate genistein using a combined liquid–liquid phase separation method. The physicochemical properties of fabricated nanoparticles were characterized by dynamic light scattering (DLS), atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FTIR). The results demonstrated that genistein encapsulated with zein nanoparticles significantly improved its water dispersibility, antioxidant activity in the aqueous phase, and photostability against UV light. Moreover, genistein encapsulated in zein nanoparticles showed a sustained release property. Furthermore, it was found that encapsulation efficiency of genistein was significantly enhanced after CMCS coating, and this effect was more pronounced after the complex nanoparticles cross-linked with calcium ions when compared with the use of zein as a single encapsulant. In addition, compared to zein nanoparticles without biopolymer coating, CMCS coating significantly enhanced the thermal and storage stability of the formed nanoparticles, and delayed the release of genistein. A schematic diagram of zein and zein/carboxymethyl chitosan (CMCS) nanoparticles formation mechanism for encapsulation of genistein was proposed. According to the results of the current study, it could be concluded that encapsulation of genistein in zein/CMCS nanoparticles is a promising approach to improve its water dispersibility, antioxidant activity, photostability against UV light and provide controlled release for food/pharmaceutical applications.

scholarly journals Study of Iron Gall Inks, Ingredients and Paper Composition Using Non-Destructive Techniques

Heritage ◽  
2019 ◽  
Vol 2 (4) ◽  
pp. 2691-2703 ◽  
Author(s):  
Victoria Corregidor ◽  
Rita Viegas ◽  
Luís M. Ferreira ◽  
Luís C. Alves
Keyword(s):  
Structural Information ◽  
Uv Light ◽  
Raw Materials ◽  
Structural Characteristics ◽  
Crystallinity Index ◽  
X Ray ◽  
Paper Degradation ◽  
Iron Gall ◽  
Non Destructive ◽  
Non Destructive Techniques

Old manuscripts are among the most important elements of the cultural and historical heritage of ancient knowledge. Unfortunately, many of them suffer from degradation, mostly those written with iron gall inks. In the present work, a study using non-destructive techniques was designed with the aim of analyzing the elemental composition and structural characteristics of iron gall inks, reproduced in laboratory, paper and their interaction when the ink is deposited on paper, inducing the paper degradation. Proton induced X-ray emission, X-ray diffraction and Fourier-transform infrared spectroscopy provided the elemental and structural information, and photography under infrared (IR) and ultraviolet (UV) light allowed the differentiation between manufactured inks. Results show that the first step of inked paper deterioration is due to acid-hydrolysis of the cellulose and the presence of reactive Fe(II) species by reducing the crystallinity index of the paper, which is affected depending on the ink recipe and the starting raw materials. These results will be useful to future studies on ancient documents written with iron gall inks, which suffer deterioration due to ink corrosion, and to differentiate between the different paper degradation mechanisms.

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