A Morphological Characterization of High Yield Chitin from Periwinkle Shells

Research on obtaining chitin from periwinkle shell is scarce due to the very low yield of chitin from this kind of shell. Thisstudy reports a method of processing periwinkle shells to obtain high yield, bio-medically suitable chitin. The experimentwas designed using IM and 2M concentrations of HCl for demineralization and a 1M NaOH concentration for deproteinization. FTIR, SEM, XRD and DTA analytical tools were used to characterize the extracted chitin. The FTIR spectral, XRD patterns and SEM analysis, revealed the complete removal of calcium carbonate by the acid concentrations used. The particle-like form of periwinkle shell was transformed to sheet-like fiber and globular-like fiber of α-chitin by increasing the concentration of HCl from1M to 2M respectively. The crystal size increased from 11.2Å (1M HCl) to 13.4Å (2M HCl). The yield of chitin from periwinkle shell also increased from 52% to 71% using 1M and 2M HCl respectively. Thus, acid concentrations can be used to alter the structure of chitin with different mechanical properties

Crab (Brachyura) shell Acid and Alkali Treatments: Influence on Thermal and Structural Properties of Isolated Acetamide-Rich Natural Polymer

Exoskeleton of crab comprises a dominating mineral (calcium carbonate, CaCO3), protein and a natural polymer (chitin). Chemical treatments have been employed at different instances to isolate pure chitin from different sources. It is thus necessary to investigate how this treatment will influence the features of chitin isolated from the same source (crab). In this study, 0.4, 0.8 and 1.2 M hydrochloric acid (HCl) were separately used to demineralize crab shell particles and this was followed by deproteinization with 0.4 and 1.2 M sodium hydroxide (NaOH) at 100 0C.  Results showed that chitin properties were influenced by concentrations of reagents. Fibrils of different forms and surface appearance were observed via Scanning Electron Microscopy (SEM). The highest crystallinity index of 71% was possessed by chitin extracted using 0.4 M HCl and NaOH while 65.5% remained the least displayed by chitin extracted with 1.2 M HCl and NaOH. This trend was similar for chitin’s thermal stability where Thermogravimetric analysis (TGA) results informed that using the highest concentrations of 1.2 M HCl and NaOH provided chitin with 80.12 kJ/mol activation energy. On the other hand, 112.54 kJ/mol was calculated for chitin isolated with the minimum demineralization and deproteinization reagents used in this study

Morphological, Mechanical and Thermal Characteristics of PLA /Cocos nucifera L Husk and PLA/Zea mays Chaff Lignin Fibre Mats Composites

Polylactide (PLA) is a biodegradable polymer with low elongation which limits its use in some applications. The incorporation of biowaste particles has been employed to improve its properties. This work thus examines the impact of lignin particles reinforced on electrospun PLA fibre mats. Acid hydrolysis (1M of HCl at 60 and 100 0C for  2 and 4 h was used to extract lignin from Cocos nucifera L (CNHL) and Zea Mays Chaff (CCL). Lignin particles were added to molten PLA, stirred, and electrospun at 26 kV, using a static aluminum collector plate placed at 121mm from the spinneret tip. Morphological examination reveals that fibre diameter of neat PLA (9.7 µm) increased from 107 – 285 % with the additions of reinforcements. Maximum tensile strength of 1.03 MPa is recorded for PLA/CNHL 60 0C /2 h. This composite maintains the highest elongation of 0.069 % compared to neat PLA (0.046 %). X-Ray diffractometer (XRD) result informs that the crystallinity of neat PLA (67.6 %) improves by 3%, with the use of CNHL 60 0C/ 2 h. Thermo gravimetric analysis (TGA) result shows that both fibre composites possess better thermal stability (380 0C) compared to reinforcing PLA fibre (3190 C)

Biomaterials for Drug Delivery: Sources, Classification, Synthesis, Processing, and Applications

A way to avoid or minimize the side effect that could result in drug delivery to cells with increased efficiency and performance in the health rehabilitation process is to use biocompatible and biodegradable drug carriers. These are essentially biomaterials that are metallic, ceramic, or polymeric in nature. The sources of these materials must be biological in its entire ramification. The classification, synthesis, processing, and the applications to which these materials are put are the essential components of having suitable target cell drug carriers. This chapter will be devoted to discussing biomaterials suitable as drug carrier for use in the health-related matters of rehabilitation

Mechanical characteristics of groundnut shell particle reinforced polylactide nano fibre

ABSTRACT The PLA-groundnut shell solution is electrospun to produce nanocomposite fibre. The spinneret containing the composite solution was placed 24.7 cm away from the aluminium collector, tilted at an angle of 30 °, and the solution flow rate kept at 1 mL/min. Groundnut Shell particle (GSP) weight fraction used was varied from 3 - 8 wt. %. Particle reinforced nanofibres were formed on the collector from the composite solution at 26 kV. These nanofibres were subjected to tensile test and the result indicates that at 6 wt. % untreated GSP reinforced fibre possessed the best tensile stiffness of 24.62 MPa. This corresponds to 2.201 % increase in Modulus of Elasticity over the unreinforced PLA (1.07 MPa). The 7 wt. % treated GSP fibre showed the least stiffness (0.33 MPa), which is 69 % reduction over that of unreinforced fibre. PLA fibre reinforced with 5 wt. % untreated GSP displayed best blend of properties over the unreinforced with increase of 286 % (4.43 x 10-4 HB), 1,502 % (1.07 MPa), 286 % (0.22 MPa), 6.8 % (0.05 J) and 1,081 % (~ 0.15 MPa) in hardness, stiffness, UTS, energy at break and stress at break respectively. However, ductility decreased by ~33.3 % when compared to the unreinforced (18.27). The 5 wt. % untreated GSP PLA reinforced fibre showed the highest UTS (0.855 MPa). The micrographs showed beads on reinforced fibres, while the virgin PLA showed no beads

Mechanical characteristics of groundnut shell particle reinforced polylactide nano fibre

ABSTRACT The PLA-groundnut shell solution is electrospun to produce nanocomposite fibre. The spinneret containing the composite solution was placed 24.7 cm away from the aluminium collector, tilted at an angle of 30 °, and the solution flow rate kept at 1 mL/min. Groundnut Shell particle (GSP) weight fraction used was varied from 3 - 8 wt. %. Particle reinforced nanofibres were formed on the collector from the composite solution at 26 kV. These nanofibres were subjected to tensile test and the result indicates that at 6 wt. % untreated GSP reinforced fibre possessed the best tensile stiffness of 24.62 MPa. This corresponds to 2.201 % increase in Modulus of Elasticity over the unreinforced PLA (1.07 MPa). The 7 wt. % treated GSP fibre showed the least stiffness (0.33 MPa), which is 69 % reduction over that of unreinforced fibre. PLA fibre reinforced with 5 wt. % untreated GSP displayed best blend of properties over the unreinforced with increase of 286 % (4.43 x 10-4 HB), 1,502 % (1.07 MPa), 286 % (0.22 MPa), 6.8 % (0.05 J) and 1,081 % (~ 0.15 MPa) in hardness, stiffness, UTS, energy at break and stress at break respectively. However, ductility decreased by ~33.3 % when compared to the unreinforced (18.27). The 5 wt. % untreated GSP PLA reinforced fibre showed the highest UTS (0.855 MPa). The micrographs showed beads on reinforced fibres, while the virgin PLA showed no beads

Strength Characteristics of Electrospun Coconut Fibre Reinforced Polylactic Acid: Experimental and Representative Volume Element (RVE) Prediction

Environmental conservation and waste control have informed and encouraged the use of biodegradable polymeric materials over synthetic non-biodegradable materials. It has been recognized that nano-sized biodegradable materials possess relatively good properties as compared to conventional micron-sized materials. However, the strength characteristics of these materials are inferior to fossil-based non-biodegradable materials. In this study, biodegradable polylactide (PLA), reinforced with treated coconut husk particulates (CCP) for improved mechanical properties, was fabricated using an electrospinning process and representative volume element (RVE) technique, and some of the obtained mechanical properties were compared. It was observed that the electrospun CCP-PLA nanofibre composites show improved mechanical properties, and some of these mechanical properties using both techniques compared favourably well. The electrospun fibres demonstrate superior properties, mostly at 4 wt.% reinforcement. Thus, achieving good mechanical properties utilising agro waste as reinforcement in PLA to manufacture nanocomposite materials by electrospinning method is feasible and provides insight into the development of biodegradable nanocomposite materials

Strength, Water Absorption, Thermal and Antimicrobial Properties of a Biopolymer Composite Wound Dressing

Conventional wound material allows bacterial invasions, trauma and discomfort associated with the changing of the dressing material, and the accumulation of body fluid for wounds with high exudate. However, there is a shift from conventional wound dressing materials to polymeric nanofibers due to their high surface area to volume ratio, high porosity, good pore size distribution, which allows for cell adhesion and proliferation. There is an urgent need to synthesis a biodegradable composite that is resistant to bacterial infection. In this study, an electrospun polylactide (PLA) composite suitable for wound dressing, with enhanced antimicrobial and mechanical properties, was produced. The neat PLA, PLA/CH (10 wt.%), PLA/CH (5 wt.%), PLA/CHS (10 wt.%), PLA/CHS (5 wt.%), PLA/CH (2.5 wt.%) /CHS (2.5 wt.%) and PLA/CH (5 wt.%)/CHS (5 wt.%), were electrospun using 0.14 g/ml solution. Results show that crystallinity (67.6%) of neat PLA declined by 3.8% on the addition of 2.5 wt.% chitin/chitosan with improved hydrophilicity of the composite. The tensile strength of neat PLA (0.3 MPa) increased (0.6 MPa) with 2.5 wt.% chitin/chitosan addition. The slight increase in the glass transition temperature from 75°C for neat PLA to 78°C of the composite fibre, showed improved ductility. The fibres showed little beads, hence suitable for wound dressing. The electrospun mats have good water absorption capacity and strong resistance against Staphylococcus aureus. Good performance was attained at 5 wt.% of chitin, chitosan and hybrid reinforcements. Therefore, a PLA/chitin/chitosan composite is recommended as a wound dressing material

Structural and Morphological Evaluations of Natural Hydroxyapatite from Calcined Animal Bones for Biomedical Applications

Several biomedical materials have been employed as drug delivery systems, but natural Hydroxyapatite (HAP) has been proven to be exceptionally better than other materials owing to its excellent bioactivity and biocompatibility properties. In this study, nat­ural HAP was obtained from bovine and caprine bones and comparatively analysed for biomedical applications. The bones were hydrothermally treated, calcined in the temperature range of 700–1100°C, held for 2 hours in an electric furnace to remove the organic contents; milled, sifted with 150 μm mesh sieve and then characterized. It was revealed by Energy Dispersive X-Ray Spectroscopy (EDS) that the bovine and caprine bone samples calcined at 1000°C had calcium/phosphorus ratio (Ca/P) of 1.66 closest to the standard of 1.67. The bovine HAP showed the best crystallinity (86.23%) at 1000°C while caprine HAP had its highest (87.25%) at 1100°C. Fourier Transform Infrared Spectroscopy (FTIR) results revealed that the calcination temperature must be greater than 700°C to isolate high quality HAP. The Scanning Electron Microscopy (SEM) showed that the samples calcined at 800°C had the largest average particle size (85.34 μm) while porosity increases with calcination temperature in both samples. The HAP obtained at a calcination temperature of 1000°C proved to have the best quality for biomedical applications