scholarly journals Dragon Fruit Foliage: An Agricultural Cellulosic Source to Extract Cellulose Nanomaterials

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7701
Author(s):  
Tuyet Phung Thi Anh ◽  
Toan Viet Nguyen ◽  
Phuong Thi Hoang ◽  
Phuong Vu Thi ◽  
Thoa Nguyen Kim ◽  
...  

In this report, we focus our effort to extract cellulose nanomaterials (CNs) from an agricultural cellulosic waste, Dragon Fruit foliage (DFF). DFF was first pretreated by several mechanical treatments and then bleached by chemical treatment to obtain bleached DFF. CNs were then produced from the hydrolysis of the bleached DFF catalyzed by sulfuric acid. We obtained CNs with a small diameter (50 to 130 nm) and length (100 to 500 nm) and a height of 3 to 10 nm. The CNs have a high crystallinity (crystallinity index 84.8%), high −COOH content (0.74 mmol. g−1), good thermal stability and a good Cu (II) adsorption capacity with an adsorption maximum of ~103 mg. g−1. These findings demonstrated the great potential of converting many agricultural cellulosic wastes into valuable cellulose nanomaterials.

Alloy Digest ◽  
1996 ◽  
Vol 45 (9) ◽  

Abstract Hastelloy C-2000 has a broad capability range for handling corrosive environments. The alloy has high resistance to reagent grade sulfuric acid, hydrochloric acid to high concentrations, and nitric acid. The alloy has outstanding localized corrosion resistance, excellent stress-corrosion cracking resistance, and good thermal stability. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance. Filing Code: Ni-516. Producer or source: Haynes International Inc.


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Kaili Song ◽  
Xiaoji Zhu ◽  
Weiming Zhu ◽  
Xiaoyan Li

AbstractCalotropis procera fiber (CPF) is the fruit fiber of C. procera and belongs to a typical cellulosic fiber. In this study, Calotropis procera fiber (CPF) was first purified in the pretreatment process including delignification and bleaching before the isolation of cellulose nanocrystal. Chemical composition of Calotropis procera fiber was determined according to TAPPI standard method. It was composed of 64.0 wt% cellulose, 19.5 wt% hemicelluloses, and 9.7 wt% of lignin. The morphology of the Calotropis procera fiber and fiber after each pretreatment process was also investigated. Cellulose nanocrystal was extracted by classical sulfuric acid hydrolysis of the pretreated Calotropis procera fiber. TEM and SEM were used to analyze the morphologies of the obtained CNC. The crystallinity, thermal stability and suspension stability of the CNC were also investigated. The interesting results proved that this under-utilized biomass could be exploited as a new source of cellulose raw material for the production of cellulose nanocrystal.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 626
Author(s):  
Siti Hajar Mohamed ◽  
Md. Sohrab Hossain ◽  
Mohamad Haafiz Mohamad Kassim ◽  
Mardiana Idayu Ahmad ◽  
Fatehah Mohd Omar ◽  
...  

There is an interest in the sustainable utilization of waste cotton cloths because of their enormous volume of generation and high cellulose content. Waste cotton cloths generated are disposed of in a landfill, which causes environmental pollution and leads to the waste of useful resources. In the present study, cellulose nanocrystals (CNCs) were isolated from waste cotton cloths collected from a landfill. The waste cotton cloths collected from the landfill were sterilized and cleaned using supercritical CO2 (scCO2) technology. The cellulose was extracted from scCO2-treated waste cotton cloths using alkaline pulping and bleaching processes. Subsequently, the CNCs were isolated using the H2SO4 hydrolysis of cellulose. The isolated CNCs were analyzed to determine the morphological, chemical, thermal, and physical properties with various analytical methods, including attenuated total reflection-Fourier transform-infrared spectroscopy (ATR-FTIR), field-emission scanning electron microscopy (FE-SEM), energy-filtered transmission electron microscopy (EF-TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results showed that the isolated CNCs had a needle-like structure with a length and diameter of 10–30 and 2–6 nm, respectively, and an aspect ratio of 5–15, respectively. Additionally, the isolated CNCs had a high crystallinity index with a good thermal stability. The findings of the present study revealed the potential of recycling waste cotton cloths to produce a value-added product.


2012 ◽  
Vol 531-532 ◽  
pp. 8-12
Author(s):  
M.A. Sai Balaji ◽  
K. Kalaichelvan

Organic fibres (Kevlar/ Arbocel / Acrylic) have good thermal stability, higher surface area and bulk density. The optimization of organic fibres percentage for thermal behaviour is considered using TGA. The temperature raise during brake application will be between 150-4000 C and this temperature zone is very critical to determine the fade characteristics during friction testing. Hence, three different friction composites are developed with the same formulation varying only the Kevlar, Arbocel and Acrylic fibres which are compensated by the inert filler namely the barites and are designated as NA01, NA02 and NA03 respectively. After the fabrication, the TGA test reveals that the composite NA03 has minimum weight loss. The friction coefficient test rig is then used to test the friction material as per SAE J661a standards. The results prove that the brake pad with minimum weight loss during TGA has higher friction stability. Thus, we can correlate the thermal stability with the stability of friction.


2013 ◽  
Vol 734-737 ◽  
pp. 2191-2194
Author(s):  
Li Li Wu ◽  
Yuan Lian ◽  
Dan Liu ◽  
Hua Zheng ◽  
Dian Wu Huang

In this study, flame retardant microcapsules were synthesized using magnesium hydroxide as core materials, melamine resin as the shell material. The structure, diameters and thermal properties of prepared microcapsules were investigated by using FTIR, ELS, DSC and TGA. The effects of core/shell ratio on the properties of microcapsules were studied.Flame retardant materials of low-density polyethylene/magnesium hydroxide microcapsules were prepared.The tensile strength and elongation at break tests were performed to determine its mechanical property.Inflammability of the materials was also studied.The results showed the prepared magnesium hydroxide microcapsule shows good thermal stability and it has free compatibility with the polymer.The composites of HDPE/MH microcapsules have good performance.


2013 ◽  
Vol 829 ◽  
pp. 62-66 ◽  
Author(s):  
Alireza Fallahi ◽  
Hossein Hosseini-Toudeshky ◽  
Seyed Mahmoud Ghalehbandi

It is the objective of this study to investigate the effect of ECAP processing and heat treatment on the mechanical properties of the UFG 7075 alloy. Also the effect of post ECAP heat treatment is investigated. The alloy is processed by ECAP after annealing as well as solution treatment to produce an UFG structure. Furthermore mechanical properties and their variations during annealing and aging are investigated. The hardness of the pre-ECAP annealed and the pre-ECAP solutionised 7075 aluminum alloy has increased significantly compared with that of the CG sample. Also hardness of ECAPed specimen has not experienced significant changes in post-ECAP heat treatment and indicated that the alloy had approximately good thermal stability.


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