scholarly journals Evaluating the potential of chitin extracted from shrimp shell wastes as support material of gold nanoclusters (AuNCs) for catalysis

2021 ◽  
Vol 1192 (1) ◽  
pp. 012032
Author(s):  
Nabila Azirah Zakaria ◽  
Ricca Rahman Nasaruddin ◽  
Wan Mohd Fazli Wan Nawawi

Abstract Thiolate-protected gold nanoclusters (AuNCs) have been intensively studied due to their appealing physicochemical properties that can be used in various applications, especially catalysis. However, thiolate-protected AuNCs in a free suspension form, tend to aggregate during catalytic reaction due to the high surface reactivity of its ultrasmall size, hence, reducing the rate of their catalytic reaction. Their recovery and reusability are also difficult. Therefore, several support materials have been studied to immobilize the thiolate-protected AuNCs for a better recovery, reusability and stability in solution and during a catalytic reaction. Herein, chitin extracted from shrimp shell waste was used as support material for the immobilization of the AuNCs protected by p-mercaptobenzoic acid ligands, using deposition-precipitation method. The free chitin and chitin immobilized with thiolate-protected AuNCs (abbreviated as AuNCs/Chitin) were characterized using FTIR. The catalytic properties of the AuNCs/Chitin were then evaluated in the hydrogenation of 4-nitrophenol in solution as the model reaction. It was found that the chitin extracted from SSW has a good potential to be support materials of thiolate-protected AuNCs because the shorter reaction time it took (12 minutes) as compared to the reaction without catalyst (60 minutes) and it can be recovered and reused twice.

2014 ◽  
Vol 69 (5) ◽  
Author(s):  
Mohamad Haqzim Ayob ◽  
Jon Efendi ◽  
Lai Sin Yuan ◽  
Sheela Chandren ◽  
Ho Chin Siong ◽  
...  

Cobalt Schiff base complex is widely used in many reactions such as reduction process, carbonylation of alcohol and oxidation of alkenes. Generally, this catalyst is in the powder form. It is difficult to separate the catalyst from the reaction mixture due to the small particles size of the catalyst. One way to easily separate the catalyst is by applying external magnetic field. However these catalysts would have to possess magnetic properties for this method to work on. One of the strategies to solve this problem is by adding magnetic material into the catalysts. Magnetite is a common magnetic material used as a support material which can be synthesized by the co-precipitation method of Fe2+ andFe3+. Normally, magnetite is covered by silica in order to stabilize and reduce its toxicity. This can be done by using the sol-gel approach. Silica coated magnetite is widely used as a support material because of its high surface area and easy catalyst separation after the reaction simply by applying an external magnetic field. In this research, cobalt Schiff base complex/silica@magnetite was synthesized from the condensation of cobalt (II) salicylaldehyde with 3-aminopropyltrimethoxy silane on the surface of silica@magnetite. The catalysts were characterized using Fourier transform infrared spectrometer, scanning electron microscopy and diffuse reflectance ultra-violet visible spectrometry. 


2012 ◽  
Vol 581-582 ◽  
pp. 418-421 ◽  
Author(s):  
Zhang Yong Liu

ZnO nanoparticles with high surface area were synthesized by hydrothermal homogeneous precipitation method, and the influences of physicochemical properties of ZnO materials on the adsorptive desulfurization performance of Ni/ZnO adsorbent were investigated. Activity evaluation showed that the Ni/ZnO adsorbent using nanosize ZnO as support materials had better adsorption performance, and the sulfur adsorption capacity was maximized depending on the surface area and particle size of ZnO materials. The thiophene removal efficiency and the breakthrough capacity (10 ppm level) were found to be 100% and 6.1 (mg of sulfur per g of adsorbent), respectively.


2019 ◽  
Author(s):  
Moritz Wolf ◽  
Nico Fischer ◽  
Michael Claeys

<p>The inert nature of graphitic samples allows for characterisation of rather isolated supported nanoparticles in model catalysts, as long as sufficiently large inter-particle distances are obtained. However, the low surface area of graphite and the little interaction with nanoparticles result in a challenging application of conventional preparation routes in practice. In the present study, a set of graphitic carbon materials was characterised in order to identify potential support materials for the preparation of model catalyst systems. Various sizes of well-defined Co<sub>3</sub>O<sub>4</sub> nanoparticles were synthesised separately and supported onto exfoliated graphite powder, that is graphite after solvent-assisted exfoliation <i>via</i> ultrasonication resulting in thinner flakes with increased specific surface area. The developed model catalysts are ideally suited for sintering studies of isolated nano-sized cobaltous particles as the graphitic support material does not provide distinct metal-support interaction. Furthermore, the differently sized cobaltous particles in the various model systems render possible studies on structural dependencies of activity, selectivity, and deactivation in cobalt oxide or cobalt catalysed reactions.</p>


2019 ◽  
Author(s):  
Chem Int

Activated carbon was prepared from molasses, which are natural precursors of vegetable origin resulting from the sugar industry. A simple elaboration process, based on chemical activation with phosphoric acid, was proposed. The final product, prepared by activation of molasses/phosphoric acid mixture in air at 500°C, presented high surface area (more than 1400 m2/g) and important maximum adsorption capacity for methylene blue (625 mg/g) and iodine (1660 mg/g). The activated carbon (MP2(500)) showed a good potential for the adsorption of Cr(VI), Cu(II) and Pb(II) from aqueous solutions. The affinity for the three ions was observed in the following order Cu2+ Cr6+ Pb2+. The process is governed by monolayer adsorption following the Langmuir model, with a correlation coefficient close to unity.


2020 ◽  
Vol 20 (11) ◽  
pp. 1001-1016
Author(s):  
Sandra Ramírez-Rave ◽  
María Josefa Bernad-Bernad ◽  
Jesús Gracia-Mora ◽  
Anatoly K. Yatsimirsky

Hybrid materials based on Mesoporous Silica Nanoparticles (MSN) have attracted plentiful attention due to the versatility of their chemistry, and the field of Drug Delivery Systems (DDS) is not an exception. MSN present desirable biocompatibility, high surface area values, and a well-studied surface reactivity for tailoring a vast diversity of chemical moieties. Particularly important for DDS applications is the use of external stimuli for drug release. In this context, light is an exceptional alternative due to its high degree of spatiotemporal precision and non-invasive character, and a large number of promising DDS based on photoswitchable properties of azobenzenes have been recently reported. This review covers the recent advances in design of DDS using light as an external stimulus mostly based on literature published within last years with an emphasis on usually overlooked underlying chemistry, photophysical properties, and supramolecular complexation of azobenzenes.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1887
Author(s):  
Viviana Quintero ◽  
Arturo Gonzalez-Quiroga ◽  
Angel Darío Gonzalez-Delgado

The conservation and proper management of natural resources constitute one of the main objectives of the 2030 Agenda for Sustainable Development designed by the Member States of the United Nations. In this work, a hybrid strategy based on process integration is proposed to minimize freshwater consumption while reusing wastewater. As a novelty, the strategy included a heuristic approach for identifying the minimum consumption of freshwater with a preliminary design of the water network, considering the concept of reuse and multiple pollutants. Then, mathematical programming techniques were applied to evaluate the possibilities of regeneration of the source streams through the inclusion of intercept units and establish the optimal design of the network. This strategy was used in the shrimp shell waste process to obtain chitosan, where a minimum freshwater consumption of 277 t/h was identified, with a reuse strategy and an optimal value of US $5.5 million for the design of the water network.


2016 ◽  
Vol 10 (5) ◽  
pp. 162-174 ◽  
Author(s):  
Trang Si Trung ◽  
Nguyen Thi Khanh Huye ◽  
Nguyen Cong Minh ◽  
Tran Thi Le Trang ◽  
Nguyen The Han

2021 ◽  
Vol 324 ◽  
pp. 03006
Author(s):  
Tri Yulianto ◽  
Dwi Septiani Putri ◽  
Shavika Miranti ◽  
Wiwin Kusuma Atmaja Putra

Feed is still one of the problems in aquaculture because it takes about 70% of operational costs. High prices is caused by imported raw materials for feed production. One possible effort to overcome this problem is to find alternative local raw materials to replace imported fish meal. The purpose of this study was to examine the proximate content of shrimp shell wastes from processing shrimp crackers (Paneus sp.) to be used as shrimp flour. Samples were colledted three times in a month, at the beginning, middle and end of the month. The waste of the heads, shells and tails of the shrimp were turned into flour for laboratory testing through proximate analysis. The data were tabulated using the Microsoft Excel softwareand then analyzed descriptively by comparing the nutrient content of shrimp waste flour with the feed requirements of mariculture. The results showed that shrimp shell flour contained protein, fat, carbohydrates and ash content of around 27.4%, 2.07%, 14.84% and 47.27%. while the resulting randemen ranged from 81.75%. Therefore, shrimp shell flour can be used as an alternative raw material for preparing marine fish feed.


Sign in / Sign up

Export Citation Format

Share Document