Emulsion templated polymer monoliths containing cellulose nanocrystals: Synthesis and adsorption properties

2021 ◽  
pp. 51802
Author(s):  
Ali Eslek ◽  
Burcu Kekevi ◽  
Hatice Hande Mert ◽  
Emine Hilal Mert
2017 ◽  
Vol 735 ◽  
pp. 235-239 ◽  
Author(s):  
Thamonwan Angkuratipakorn ◽  
Jirada Singkhonrat ◽  
Alfred A. Christy

The adsorption properties of water molecules on cellulose and cellulose nanocrystals (CNCs), isolated from defatted rice bran (DRB) by 55% sulfuric acid hydrolysis under sonication were investigated. The powdered samples of cellulose and CNCs were analysed by using near infrared spectroscopy (NIR) and gravimetry at 38% and 55% humidities. Small amounts of samples were dried under vacuum at 120°C and the NIR spectra of the dry samples and their spectra during the adsorption water molecules were measured by using an NIR spectrometer equipped with a transflectance accessory and a DTGS detector. The quantitative adsorption of water molecules by the samples was determined by gravimetry. Second and fourth derivative profiles of the NIR spectra were used in understanding the chemistry of adsorption of water molecules and the adsorption processes by the samples. The results show that the adsorption of water molecules by the cellulose samples gives rise to three prominent peaks that can be related to the water molecules engaged in hydrogen bonding with C2, C3 and C6-OH groups on the glucose units of the cellulose polymers. Furthermore, the cellulose nanocrystals adsorb twice as much of water as the cellulose polymer. It is also clear from the results that C2 and C3-OH groups in the glucose units adsorb water molecules at a faster rate than the C6-OH group and responsible for nearly 50% of the water adsorption.


2018 ◽  
Vol 11 ◽  
pp. 46-55
Author(s):  
E.V. Ulyanova ◽  
◽  
V.A. Vasilkovskiy ◽  
O.N. Malinnikova ◽  
◽  
...  

2019 ◽  
Author(s):  
Valentina Guccini ◽  
Sugam Kumar ◽  
Yulia Trushkina ◽  
Gergely Nagy ◽  
Christina Schütz ◽  
...  

The magnetic alignment of cellulose nanocrystals (CNC) and lepidocrocite nanorods (LpN), pristine and in hybrid suspensions has been investigated using contrast-matched small-angle neutron scattering (SANS) under in situ magnetic fields (0 – 6.8 T) and polarized optical microscopy. The pristine CNC (diamagnetic) and pristine LpN (paramagnetic) align perpendicular and parallel to the direction of field, respectively. The alignment of both the nanoparticles in their hybrid suspensions depends on the relative amount of the two components (CNC and LpN) and strength of the applied magnetic field. In the presence of 10 wt% LpN and fields < 1.0 T, the CNC align parallel to the field. In the hybrid containing lower amount of LpN (1 wt%), the ordering of CNC is partially frustrated in all range of magnetic field. At the same time, the LpN shows both perpendicular and parallel orientation, in the presence of CNC. This study highlights that the natural perpendicular ordering of CNC can be switched to parallel by weak magnetic fields and the incorporation of paramagnetic nanoparticle as LpN, as well it gives a method to influence the orientation of LpN.<br>


Author(s):  
Shaoqu Xie ◽  
◽  
Xiao Zhang ◽  
Michael P. Walcott ◽  
Hongfei Lin ◽  
...  

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