Manufacturing Nanostructured and Microstructured Chitosan Prepared By Milling Shrimp Shell

ARTICLE ABSTRACT This research aimed to produce nano-chitosan. Nanocrystallite. Shrimp shells have been prepared by using a high-energy planetary ball with an optimal rotational speed. The raw material was subjected to standard chemical processing for chitin extraction, followed by deacetylation to obtain nanocrystallite chitosan, which is characterized by Scanning Electron Microscope SEM Fourier, Transform Infrared Spectrometry FT-IRand X-ray diffraction (XRD).


Introduction
In Algeria, shrimp are the most important crustacean sea food.Shrimp shel wastes which constitute approximately 50% of the total weight of shrimp become an environmental risk in Algeria due to the increase in the total production of shrimp (Toan, 2009).The utilization of shrimp shell wastes could be used in industry, corrosion, biotechnology and and biomedecine.
Chitin, is a natural polysaccharide of major importance, The main commercial sources of chitin have been crab and shrimp shells.In industrial transformation, chitin is extracted from crustaceans by acid treatment dissolve the calcium carbonate followed by an alkaline extraction to solubilize proteins (Rinaudo, 2006).
Chitosan is a modified natural carbohydrate polymer derived from chitin which has been found in a wide range of natural sources such as crustaceans, insects and some algae (Hossain & Iqbal, 2014).By partial deacetylation under alkaline conditions,one obtains chitosan, which is the most important chitin derivative in terms of applications (Kumari, Kumar Annamareddy, Abanti, & Kumar Rath, 2017; Puvvada, Vankayalapati, & Sukhavasi, 2012; Rinaudo, 2006).
The net cationicity, as well as the presence of multiple reactive functional groups in the molecule make chitosan a sought after biomolecule (Prashanth & Tharanathan, 2007).
A serious challenge for the scientific community is to develop high-performance materials that meet the requirements related to environmental sustainability (Giuliani et al., 2018;Hossain & Iqbal, 2014).
In this sense, we have synthesized a chitosan from shrimp shell carapace powder obtained by mechanical milling, which will find its use in the protection against corrosion (Chen, Yang, & Jang, 2000; Giuliani et al., 2018).

Sample preparation Cleaning of shrimp shells
The shrimp shells used in this study were obtained after the harvest of marine shrimp from the Algeria.The shells remained in the freezer at 0 °C until use.They were washed in running water to remove the excess organic material and dried at 80 °C for 24 h.The dried samples were milled using a planetary mill.20 g of shell powders were used for further analysis (Figure 1).

Milling (Planetary mills)
At present planetary mills of high accelerations providing fast and efficient milling of various materials on industrial scale are commercially available in Algeria.

The principle of planetary mills performance
Planetary mills are usually provided with 4 jars (Figure 2) rotating around the central axis and simultaneously around their own axes in the opposite direction .Material and milling bodies (8 balls with diametre equal for 1.9 mm ) are loaded into the jars.The treated material particles undergo multiple collisions with the grinding media and the jar walls.The efficiency of planetary mills is the result of the high kinetic energy of grinding media.High velocity of moving milling bodies exerts high stress on the activated material.In this study, velocity is between 250 rpm and 300 rpm during 1 hour.

Scanning Electron Microscopy (SEM)
The SEM with accelerating voltage 30 kv were used for characterization of precursor, chitine and chitosan.Operating at 30 kV where chitin have a uniform morphology with lamellar organization and specifically more crystalline appeared for chitin.The SEM Mircograph of chitosan shown in Figures 3, 4 and 5 by using SEM , stating that chitosan has smooth surface morphology with minimum residues.
Figure 7 representing the absorption vs. wave number) shows in a different manner than the previous figures, the infrared spectrums in a different spectrum: absorption vs. wave number, recommended for quantitative determinations.The absorption bands can be easily assigned to some molecular fragments: the dominant band with a maximum of 1629.4867cm-1 is owed to the valence's vibrations of the bindings C-H.The group of bands ranging from 648.5568 cm-1 is characteristic to the amidic group.The band from 2699.2703 cm -1 is determined by υ(-C=O) of the amide group CONHR of the chitosan.The bands 1577.7558cm -1 (chitosan) is determined by υ(-C=O) of the proton amide group.The band 1160.7457cm -1 (chitosan) is determined by υas(C=O) oxygen bridges resulting from the deacetylation of the chitosan.

Conclusion (TNR 14pt., bold)
The importance of chitin and chitosan increased lately, on one hand due to the fact that they represent sources of renewable and biodegradable biomaterials, and on the other hand for that purpose to a better knowledge of their functionality through applications in domains such as biology, pharmacy, biotechnology, medicine and the chemistry of materials.The biodegradability, and bioactivity represent a unique set of biological properties that confer the chitosan a potential for applications in the ceveral industry.
The present study confirmed that the shrimp carapace can be transform into chitosan after milling by planetary mill, and this method is an effective in solving one of the greatest environmental and economic problems in Algeria .
By employing FTIR spestroscopy, all functional groups in chitosan macromolecules are elucidated.

Knowledgment (TNR 12pt. bold)
This paper is an output of the science project Nanomaterials and Corrosion phenomena

Figure 1 :
Figure 1: Powder obtain after shrimp shell grinding

Figure 2 :
Figure 2: The principle of planetary mills performance

Figures 5 ,
Figures 5, 6 and 7 represented the FTIR of Shrimp Shell, chitin and chitosan.Figures 5, 6 and 7 shows the infrared spectrum of the chitin in the spectrum field 2000-400 cm -1 , 2000-400 cm - 1 , 4000 -400 cm -1 , and 2000-400 cm -1 , in the form transmittance vs. wave number.The bands are generally large due to the macromolecular character of the compound and because of the numerous intermolecular bindings of hydrogen, manifested even in the solid state of the sample (Negrea, Caunii, Sarac, & Butnariu, 2015).