Crab Shell Particles Research Articles

Enhancing mechanical properties of aluminium 6063 with crab shell particle reinforcement

The versatility and beneficial properties of aluminium 6063 make it an excellent material for various applications, but limited in engineering production where strength is a major material selection factor. The utilization of natural resources in material science has gained prominence due to the quest for sustainable and innovative materials. This work explores the development and characterization of an aluminium matrix composite reinforced with crab shell particles (CSPs). The CSPs are produced via the milling process for 72 h and the CSPs are incorporated in varying percentages (0–20 wt%) into the aluminium matrix using a stir casting technique, the mechanical properties (tensile strength, compressive strength, % elongation, and impact energy) of the composites are determined using an Instron universal testing machine (UTM) and a Charpy impact testing machine, respectively. A scanning electron microscope (SEM) is used to examine the microstructure of the composite fracture surfaces and Gywddion 2.65 software is used to view the SEM images of the fracture surfaces in three dimensions (3D). The results revealed that tensile strength, compressive strength, % elongation, and impact energy are enhanced by adding varying percentages of CSPs on the aluminium 6063 composites.

Influence of Pressureless Sintering under an Inert Atmosphere on Microstructural, Microhardness, and Tribological Properties of Uniaxial Compacted Crab Shell Particles

Influence of Pressureless Sintering under an Inert Atmosphere on Microstructural, Microhardness, and Tribological Properties of Uniaxial Compacted Crab Shell Particles

Crab (<i>Brachyura</i>) 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 °C. 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.

Development of crab shell particle reinforced polylactic acid filaments for 3D printing application

In the polymeric 3D printing process, composite material development is based on preparing feedstock material such as polymeric filaments. The present work focuses on recycling crab shell particles as bio fillers for developing Polylactic Acid feedstock material. The extruded filament's intrinsic properties, such as tensile strength, diameter deviation, and surface roughness, were measured to its crab shell composition of 0, 2, 4, 6, 8, and 10 wt%. The results depict that the maximum tensile strength of 61.3 MPa was achieved on the 8% crab shell -reinforced PLA polymeric filaments. A minimum diameter deviation of 0.001 was observed on the 2% crab shell-reinforced PLA filaments. The surface morphology of the extruded PLA/crab shell filaments of 8% possesses uniform distribution of added particles in the polymeric matrix. From the overall results, the PLA/crab shell filament of 8% composition is an optimal composition feedstock material for the 3D printing application to develop biomaterials like bio-scaffolds.

Fabrication, characterisation, and application of green crosslinked sodium alginate hydrogel films by natural crab-shell powders to achieve drug sustained release

In this study, natural crab-shell particles (CSP) and deacetylated crab-shell particles (dCSP) were used as crosslinking agents at the present of glucolactone to obtain high strength mono-crosslinked and bi-crosslinked sodium alginate (NaAlg) hydrogel films, respectively. The results indicated that the CSP in the system could occur Ca2+ crosslinking, and the addition of dCSP could help to form both Ca2+ crosslinking and polyelectrolytes interactions with NaAlg. The remaining unreacted CaCO3 could enhance the thermal stability of the films due to the high thermally stable CaCO3. The surface hydrophobicity, gel properties, mechanical strength and thermal stabilities of those bi-crosslinked NaAlg hydrogel films were better than those of neat NaAlg film and mono-crosslinked NaAlg hydrogel films, which overcome the inferior thermo-mechanical properties for traditional hydrogel films. In addition, the releasing time of those prepared hydrogel films for diclofenac sodium was higher than 36 h, which illustrated sustained drug releasing activity. The CSP modified NaAlg hydrogel film with 0.5% GDL content exhibited the highest cumulative release amount. The proposed approach is a promising green crosslinking technique to develop high performance NaAlg hydrogel films that can realize active ingredients and drugs sustained release in food packaging and medical wound dressing areas.

Bioprocess development as a sustainable platform for eco-friendly alkaline phosphatase production: an approach towards crab shells waste management

BackgroundThere are substantial environmental and health risks associated with the seafood industry's waste of crab shells. In light of these facts, shellfish waste management is critical for environmental protection against hazardous waste produced from the processing industries. Undoubtedly, improved green production strategies, which are based on the notion of "Green Chemistry," are receiving a lot of attention. Therefore, this investigation shed light on green remediation of the potential hazardous crab shell waste for eco-friendly production of bacterial alkaline phosphatase (ALP) through bioprocessing development strategies.ResultsIt was discovered that by utilizing sequential statistical experimental designs, commencing with Plackett–Burman design and ending with spherical central composite design, and then followed by pH-uncontrolled cultivation conditions in a 7 L bench-top bioreactor, an innovative medium formulation could be developed that boosted ALP production from Bacillus licheniformis strain ALP3 to 212 U L−1. The highest yield of ALP was obtained after 22 h of incubation time with yield coefficient Yp/s of 795 U g−1, which was 4.35-fold higher than those obtained in the shake-flask system. ALP activity has a substantial impact on the volatilization of crab shell particles, as shown by the results of several analytical techniques such as atomic absorption spectrometry, TGA, DSC, EDS, FTIR, and XRD.ConclusionsWe highlighted in the current study that the biovalorization of crab shell waste and the production of cost-effective ALP were being combined and that this was accomplished via the use of a new and innovative medium formulation design for seafood waste management as well as scaling up production of ALP on the bench-top scale.

Effect of Compaction Pressure on the Physical, Mechanical, and Tribological Behavior of Compacted Crab Shell Particles Prepared Using Uniaxial Compaction Route

Effect of Compaction Pressure on the Physical, Mechanical, and Tribological Behavior of Compacted Crab Shell Particles Prepared Using Uniaxial Compaction Route

Multielemental Determination of Rare Earth Elements in Seawater by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) After Matrix Separation and Pre-concentration With Crab Shell Particles

Considering the unique characteristics of rare earth elements (REEs), the presence of REEs beyond specific limits will adversely affect the environment and it can be employed as a powerful probe for investigating hydrogeochemical processes. This requires sensitive determination of REEs in natural seawater. A matrix separation and pre-concentration technique using the mini-column packed with crab shell particles (CSPs) by inductively coupled plasma mass spectrometry (ICP-MS) as a means of determination has been developed. The aim of the proposed method was to simultaneously determine 16 REEs (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) at trace or ultra-trace concentrations in seawater. The biosorption capacity of CSPs was found to achieve 1.246–1.250 mg g−1 for all elements. In order to optimize performance of the method, the effects of analytical parameters concerning oscillation time, solution pH, salt concentration and eluent concentration were explored. Under the optimal conditions, the detection limits of REEs ranged 0.0006–0.0088 μg L−1, and relative standard deviations (n = 7) varied between 0.55 and 1.39%. The accuracy of developed method was evidenced by applying it to the analysis of REEs in seawater samples, with the overall recoveries at a level of 95.3 and 104.4%. Together, this work provides a promising and cost-effective CSPs-based pretreatment approach for REEs detection in sea environment.

Assessment of blue crab Shell (Callinectes sapidus) particles as bio‐based filler to EPDM rubber

AbstractThe use of waste and biodegradable materials as alternative substitutes in different areas is supporting green production in recent years. The utilization of such materials is supporting an economical way, while an environmentally and friendly approach is increased sustainability. In this context, the replacement of carbon black, which is frequently used in the rubber industry but has many drawbacks, with waste and a biodegradable filling material has attracted the attention of researchers over the past decades. In this study, ethylene propylene diene termonomer (EPDM) and EPDM with different blue crab shell (BCS) incorporated into rubber matrix were produced. The effect of carbon black and BCS content within the EPDM matrix on the rheological, mechanical, morphological, and thermal properties were investigated. The rheological analysis revealed that BCS added to the EPDM matrix enhanced the vulcanization parameters. Moreover, the addition of BCS into the EPDM matrix up to 12 phr increased the value of T50 temperature, tensile strength, and crosslinking density of composite material. In conclusion, it was revealed that BCS could be used as an alternative filling material in rubber industry, such biodegradable and bio‐based materials could become an important substitute with the economic and environmental benefits.

Mechanical, Chemical and Morphological Analysis of Crab shell/Sisal Natural Fiber Hybrid Composites

ABSTRACT Natural fiber-reinforced hybrid composites find wide applications in recent decades owing to its biodegradability, low density, and low-cost benefits. The work reported investigates, the effect of adding crab shell particles over sisal-reinforced epoxy hybrid composites in different weight percentages such as 0 wt.%, 2 wt.%, 4 wt.%, and 6 wt.%. Mechanical properties, morphological characters, X-ray diffraction analysis, and Fourier transform infrared spectroscopy were carried out for prepared hybrid composites. The inclusion of up to four weight percentage of crab shell particles exhibited considerable improvements in tensile (50%) and flexural strength (38%) in contrast to other combinations. Addition of more than 4 wt. % of crab shell particles in the polymer composites showed decreasing properties, due to the agglomeration effect between fiber and matrix. This clearly showed that the inclusion of crab shell particles into the polymer matrix considerably improves the flexural and tensile strength of hybrid composites. Morphological behavior of fractured surface confirmed the existence of better bonding between the fiber and matrix. Functional groups of sisal fiber and crab shell particles were identified using FTIR. The crystallinity index (CI) and crystallinity percentage of sisal fiber and crab shell particles are 0.43, 0.44 and 63.76%, 63.95%, respectively.

Double-Chitinase Hydrolysis of Crab Shell Chitin Pretreated by Ionic Liquid to Generate Chito-Oligosaccharide

An efficient double-chitinase hydrolysis of crab shell particles (CSP) pretreated by ionic liquids was investigated in this work. First, two family 18 chitinase genes (chip1 and chip2) from Paeniba...

Electroless nickel – phosphorus coating on crab shell particles and its characterization

Being hydrophilic material, crab shell particles have only a limited number of applications. It is, therefore, necessary to modify the surface of the crab shell particles. To make them useful ever for the applications, the main theme we proposed in this article is to utilize crab shell particles (CSP) with the core coated with nickel phosphorus (NiP) as a shell using the electroless coating process. For dealing with serious environmental problems, utilization of waste bio-shells is always an important factor to be considered. Chelating ability of crab shell particles eliminates the surface activation in this work proceeding to the coating process. The functional group, phase structure, microstructure, chemical composition and thermal analysis of CSP and NiP/CSP were characterized using Fourier transform infra-red spectroscopy (FTIR), x-ray diffraction analyzer (XRD), scanning electron microscope (SEM), energy-dispersive x-ray spectroscopy (EDS), and thermogravimetric analysis (TGA). The combination of an amorphous and crystalline structure was exhibited by CSP and NiP/CSP. NiP/CSP has shown a better thermal stability when compared to uncoated CSP. Stability test, adsorption test, and conductivity test were conducted for the study of adsorption behavior and conductivity of the particles. CSP presented a hydrophilic property in contrast to hydrophobic NiP/CSP. NiP/CSP presented a conductivity of about 44% greater compared to the CSP without any fluctuations.

Discussion on the feasibility of using proteinized/deproteinized crab shell particles for coating applications: Synthesis and characterization

The discussion on the application of natural bio hybrid organic–inorganic fillers (crab shell particles) for coating application forms the focus of this work. The utilization of shells of marine organism is growing enormously in view of its mechanical and thermal properties. However, the application of proteinized crab shell particles (CSP) or deproteinized crab shell particles (DCSP) for coating field remains a question mark. Deproteinization is done by removing the organic matrix from the crab shell particles using the deproteinization/depolymerization method. Washburn capillary test, adsorption and hydro-stability of crab shell were conducted for studying the surface property of particles in hydro environment. The maximum adsorption capacity was observed for CSP in contrast to hydrophobic DCSP. Stability test had shown the dissolution of CSP. Thermogravimetric analyzer and differential scanning calorimeter results have shown the thermal instability of DCSP on the removal of organic matrix from the crab shell particles. Characterization was done extensively using Fourier transform infrared spectroscopy, X-ray diffractometer and scanning electron microscope.

Structural and Functional Analysis of a Lytic Polysaccharide Monooxygenase Important for Efficient Utilization of Chitin in Cellvibrio japonicus

Cellvibrio japonicusis a Gram-negative soil bacterium that is primarily known for its ability to degrade plant cell wall polysaccharides through utilization of an extensive repertoire of carbohydrate-active enzymes. Several putative chitin-degrading enzymes are also found among these carbohydrate-active enzymes, such as chitinases, chitobiases, and lytic polysaccharide monooxygenases (LPMOs). In this study, we have characterized the chitin-active LPMO,CjLPMO10A, a tri-modular enzyme containing a catalytic family AA10 LPMO module, a family 5 chitin-binding module, and a C-terminal unclassified module of unknown function. Characterization of the latter module revealed tight and specific binding to chitin, thereby unraveling a new family of chitin-binding modules (classified as CBM73). X-ray crystallographic elucidation of theCjLPMO10A catalytic module revealed that the active site of the enzyme combines structural features previously only observed in either cellulose or chitin-active LPMO10s. Analysis of the copper-binding site by EPR showed a signal signature more similar to those observed for cellulose-cleaving LPMOs. The full-length LPMO shows no activity toward cellulose but is able to bind and cleave both α- and β-chitin. Removal of the chitin-binding modules reduced LPMO activity toward α-chitin compared with the full-length enzyme. Interestingly, the full-length enzyme and the individual catalytic LPMO module boosted the activity of an endochitinase equally well, also yielding similar amounts of oxidized products. Finally, gene deletion studies show thatCjLPMO10A is needed byC. japonicusto obtain efficient growth on both purified chitin and crab shell particles.

Biosorption Modeling with Multilayer Perceptron for Removal of Lead and Zinc Ions Using Crab Shell Particles

Crab shell particles were tested for its capacity to remove Pb2+ and Zn2+ ions from the aqueous solution and evaluated in a batch reactor. The binding of Pb2+ and Zn2+ ions with crab shell particles was found to be affected significantly by pH, with optimal sorption observed at pH 4.5. The influence of temperature on metal uptake showed that sorption process is favorable at room temperature and increasing the temperature decreases the Pb2+ and Zn2+ ion uptake. The effect of co-ions (Na+, Ca2+, K+, and Mg2+) in addition to Pb2+ and Zn2+ ion present in the aqueous solution was also studied. The results obtained were modeled with multilayered perceptron (MLP) and compared with other standard models like Langmuir model, Freundich model, Redlich–Peterson model and Sips model. Result shows that MLP can be efficiently used to model the biosorption system.

Efficiencies of chitosan nanoparticles and crab shell particles in europium uptake from aqueous solutions through biosorption: Synthesis and characterization

The US Department of Energy declared Europium as one of the most critical rare earth elements. Industrial and radioactive wastewater containing Europium(III) may pose a problem to the environment when discharged into the groundwater or aquatic streams. This work reports the uptake of Europium from aqueous solution by biosorption onto crab shells powder and chitosan nanoparticles as novel biosorbents for Europium(III) ion. Chitosan Nanoparticles were synthesized by the ionic gelation method. Equilibrium and kinetic studies were conducted by batch adsorption studies in order to find the optimum metal uptake conditions with the present biosorbents. The extent of adsorption was found to be a function of solution pH, contact time, metal ion concentration and adsorbent dose. The experimental data were fitted to Langmuir, Freundlich and Temkin isotherms and the data were analyzed on the basis of Lagergren pseudo-first order, pseudo-second order and Weber–Morris models. The maximum monolayer adsorption capacity of the Chitosan nanoparticles and crab shell powder was found to be 114 and 3.2 mg g−1 respectively. The results indicated the Chitosan nanoparticles could remove Europium(III) more effectively than the crab shell powder under optimum conditions. Characterization and ligand complexation behavior of the chitosan nanoparticles and crab shell powder were extensively interrogated by Dynamic Light Scattering (DLS), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy analysis (SEM).

Effect of crab shell particles on the thermomechanical and thermal properties of polybenzoxazine matrix

For various molecular ratios ranging between 0% and 30%, the effect of Crab Shell Particles (CSP) on the thermal and thermomechanical properties of polybenzoxazine has been studied. The high contents of CaCO3 particles in CSP clearly improve both the thermomechanical and thermal properties of the polybenzoxazine corresponding to a gain in storage modulus and glass transition temperature of 137% and 25%, respectively, at 30% CSP loading. Thermal analysis reveals that the polybenzoxazine matrix filled with CSP also increases the initial decomposition temperatures and the char yield of composites which reaches 49% at maximum CSP content.

Modified crab shell particles for the removal of lead[II] ions from aqueous solutions

The ability of crab shell particles to remove lead[II] was evaluated in a batch reactor and in a fixed-bed column. The binding of lead[II] by crab shell was found to be affected significantly by pH, with maximum sorption capacity 714 mg/g observed at pH 4. The sorption isotherm of lead[II] on crab shell particles was modelled by the application of Langmuir followed by Sips, Redlich–Peterson and Freundlich. The kinetic data followed pseudo-secondorder kinetics. A glass column (2 cm I.D and 35 cm height) was used to study the continuous lead[II] biosorption performance of crab shell particles with different bed heights.

Biosorption characteristics of crab shell particles for the removal of manganese(II) and zinc(II) from aqueous solutions

This work explores the potential of crab ( Portunus sanguinolentus) shell particles for the removal of manganese(II) and zinc(II) ions from aqueous solutions. The removal of metal ions by crab shell was found to be pH dependent, with optimum sorption occurring at pH 6 for both Mn(II) and Zn(II). The mechanism of metal removal by crab shell was identified as micro-precipitation of metal carbonates followed by adsorption onto chitin at the surface of crab shell, which was confirmed by pH edge and EDX analysis. The process of metal biosorption was rapid (90% removal in 120 min for Mn(II) and 90% removal in 90 min for Zn(II)) at an initial metal concentration of 500 mg/L. Modeling results revealed that Mn(II) and Zn(II) kinetics data were successfully described using pseudo-first and -second order models, compared to the Elovich equation. Furthermore, isotherm experiments revealed that crab shell possesses high uptake capacities of 69.9 and 123.7 mg/g for Mn(II) and Zn(II), respectively, according to the Langmuir model. Possibility of desorption and subsequent reuse of crab shell was attempted using 0.1 M HCl as elutant and the results were successful with the elutant exhibiting more than 99% elution efficiency for both Mn(II) and Zn(II).

Single and binary biosorption of cerium and europium onto crab shell particles

The ability of crab shell to biosorb two rare earth elements (REE), namely cerium(III) and europium(III) from single and binary systems has been studied. Crab shell majorly comprised of calcium carbonate, protein and chitin. Experiments to identify the role of these constituents in REE biosorption revealed that calcium carbonate was mainly responsible for REE removal. Microprecipitation of REE by carbonate ions and subsequent settling on the surface of crab shell was identified as major mechanism responsible for crab shell biosorption performance. At optimum pH of 6, in single component system, crab shell exhibited maximum Ce(III) and Eu(III) uptakes of 144.9 and 49.5 mg/g, respectively, according to the Langmuir model. In binary systems, both Ce(III) and Eu(III) compete with each other resulted in decreased uptake. In an attempt to model the binary biosorption data, Sheindorf–Rebhun–Sheintuch equation provided more accurate prediction of isotherm data compared to extended Langmuir model with constant interaction factor. Kinetic experiments revealed that equilibrium was attained in 60 min, followed by complete saturation in 2 h, for both Ce(III) and Eu(III). Pseudo-first order model better predicted the kinetic data with high correlation coefficients and low % error values than pseudo-second order model.