Papers by Maryam Rahimi Kord Sofla
Cellulose, 2019
Cellulose nanofibres (CNFs) are attractive as a material because they can be produced on a large ... more Cellulose nanofibres (CNFs) are attractive as a material because they can be produced on a large scale, they are renewable, biodegradable and have a wide range of applications. The high-speed blender is an efficient, simple mechanical technique for producing CNF from agricultural waste such as bagasse. The highly hydrophilic nature of CNF restricts its applicability for use in non-aqueous environments, such as those required for preparing composites and for filter applications. This research studied the relationship between blending time in a high-speed blender and the nanofibrillation process with acetylation as a pretreatment, to develop a new method for creating high quality CNF. Non-acetylated and acetylated CNF was generated using blending times of 5-60 min, and their physical and chemical properties were compared. Fibrillation occurred quickly initially, and increased with increasing blending time although the aspect ratio decreased from 72 to 56 which was measured using a rheological approach while SEM was used to measure the decrease in diameter. Fibre cutting mechanisms were dominant. Acetylation as a pretreatment reduced energy consumption, improving CNF properties using shorter blending times. Apart from higher hydrophobicity, acetylated CNF had higher thermal stability and higher crystallinity and dispersed well in acetone. The combination of acetylation as a pre-treatment coupled with the simple high speed blender technique, has significant advantages for producing high quality CNF, which is less hydrophilic, and was produced with lower energy consumption.
Science & Engineering Faculty, 2017
The present invention relates to nanofibre materials suitable for use as filtration materials. In... more The present invention relates to nanofibre materials suitable for use as filtration materials. In particular, the nanofibre materials are cellulosic nanofibre. 5 materials prepared by a process in which cellulosic nanofibre materials are freeze dried to form a porous material having a high specific surface area. The materials are useful in filtering nanoparticulate matter from air and exhausts.
This study compared the fundamental properties of cellulose nanocrystals (CNC) and cellulose nano... more This study compared the fundamental properties of cellulose nanocrystals (CNC) and cellulose nanofibrils (CNF) extracted from sugarcane bagasse. Conventional hydrolysis was used to extract CNC while ball milling was used to extract CNF. Images generated by scanning electron microscope and transmission electron microscope showed CNC was needle-like with relatively lower aspect ratio and CNF was rope-like in structure with higher aspect ratio. Fouriertransformed infrared spectra showed that the chemical composition of nanocellulose and extracted cellulose were identical and quite different from bagasse. Dynamic light scattering studies showed that CNC had uniform particle size distribution with a median size of 148 nm while CNF had a bimodal size distribution with median size 240 ± 12 nm and 10 μm. X-ray diffraction showed that the amorphous portion was removed during hydrolysis; this resulted in an increase in the crystalline portion of CNC compared to CNF. Thermal degradation of cel...
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Papers by Maryam Rahimi Kord Sofla