Carbon Nano Research Articles

Photoresponsive Carbon-Azobenzene Hybrids: A Promising Material for Energy Devices.

Advancements in renewable energy technology have been a hot topic in the field of photoresponsive materials for a sustainable community. Organic compounds that function as photoswitches is being researched and developed for use in a variety of energy storage systems. Azobenzene photoswitches can be used to store and release solar energy in solar thermal fuels. This review draws out the significance of azobenzene as photoswitches and its recent advances in solar thermal fuels. The recent developments of nano carbon templated azobenzene, their interactions and the effect of substituents are highlighted. The review also introduces their applications in solar thermal fuels and concludes with the challenges and future scope of the material. The advancements of solar thermal fuels with cost effective and desired optimal properties can be explored by scientists and engineers from different technological backgrounds.

Low temperature co-fired ceramic (LTCC)- based biosensor for detection of vanadium using immobilized Arachis hypogaea alkaline phosphatase on multi walled carbon nanotubes ethyl cellulose sponge matrix

Studies on enzyme based thermometric biosensor are limited. Here, we report on fabrication of an alkaline phosphate based thermometric biosensor. We designed alkaline phosphatase inhibition based biosensor for detection of vanadium using immobilized alkaline phosphatase on multi walled carbon nano tubes (MWCTs) ethyl cellulose sponge matrix. We isolated protein from plant source, partially purified and fabricated a miniature ceramic viz. LTCC (low temperature co-fired ceramics technology) based biosensor for detection of vanadium. This biosensor consists of a microreaction chamber with buried heaters. Alkaline phosphatase has been isolated from the seeds of ‘Arachis hypoghaea’ was studied for its biochemical properties viz. optimum pH and temperature. The partially purified enzyme was immobilized using carboxyl-functionalised carbon nanotubes (CNTs) by cross linking with epichlorohydrin (ECH) along with a matrix of ethyl cellulose. The developed LTCC based biosensor on testing indicated its linear response to vanadium concentration up to 9 mM with a relatively high sensitivity of about 147 nA/mM. Thus, we have demonstrated a LTCC based biosensor using immobilized alkaline phosphatase for detection of vanadium.

The influence of various nanofiller materials (CNTs, GNPs, and GOPs) on the natural frequencies of Nanocomposite Cylindrical Shells: A comparative study

The present research compares the influences of nanofiller materials on the free vibrational performance of Nanocomposite Cylindrical Shells (NCSs). For this purpose, three well-known nanofiller materials covering Carbon Nano Tubes (CNTs), Graphene Nano Platelets (GNPs), and Graphene Oxide Powders (GOPs) are implemented to improve polymer matrix and create nanocomposite materials. Accordingly, the modified rule of the mixture is employed to find the mechanical properties related to the CNT-nanocomposite. At the same time, the Halpin-Tsai scheme is employed to determine the GNP and GOP-nanocomposites mechanical features. Additionally, four functionally graded (FG) distribution patterns (DPs) are utilized to scatter the nanofillers along with the NCSs. In addition, the First-order Shear Deformation Theory (FSDT) and general shell scheme are implemented to find the basic relationships of the NCSs. Furthermore, Hamilton's principle is applied to derive the governing equations of motion for the NCSs. Next, the well-arranged method, namely the Generalized Differential Quadrature Method (GDQM), is implemented to discretize the equations of the motion. Then, the solution of the standard eigenvalue is joined to the list to extract the natural frequency outputs related to the NCSs. After that, to confirm the present method, multiple benchmarks are compared with the results of the submitted procedure for Carbon Nanotubes Reinforced (CNTR) and Graphene Nano Platelets Reinforced (GNPR) NCSs. It should be mentioned that there is no study related to the natural frequencies (NFs) of the Graphene Oxide Powders Reinforced (GOPR) NCSs in the open literature. Lastly, various parametrical examples are presented to explain the influences of the three kinds of nanofillers on the free vibration responses of NCSs.

Effect of nano graphene and CNT addition on coating properties in friction surfacing process

Abstract In this study, the wear behaviour of the composite material obtained as a result of the coating process by adding nano-size powder to the consumable rod with the friction surfacing method was investigated. An amount of 3–5 wt% nano graphene and carbon nano tube (CNT) were added into the hole drilled at a certain depth in the center of the consumable rod, and then the rod was subjected to sintering process. The obtained consumable rod was deposited on the substrate material at a certain rotational speed, horizontal and vertical progression speeds by friction surfacing method. Wear tests were carried out by subjecting the deposited surface samples to the pin-on-disc wear test. According to the results obtained, the increase in the additive ratio decreased the wear rate by approximately 30% in the 3 wt% graphene additive sample and 75% in the 5 wt% additive sample for 900 m wear distance. The same CNT additive ratios decreased the wear rate in the sample by 41% and 58%, respectively.

Low‐dielectric and low‐temperature curable fluorinated nano carbon/polyimide composites with 6‐aminoquinoline for end capping

AbstractOne challenge in the high‐performance dielectric material of polyimide (PI) is to obtain the excellent comprehensive properties at low curing temperature for advanced IC package. In this work, 6‐aminoquinoline (AQL) is introduced through covalent bonds for end capping to obtain a low‐temperature curable PI at first. The results demonstrate that with very limited introduce (2.76%) of AQL, the imidization index could reach as high as 1.01 at 200°C. Then, fluorinated nano carbon (FC) is further introduced resulting in the fluorinated nano carbon/polyimide (FCPI) composites, which effectively reduces the dielectric constant (1 wt%, 2.75 @ 1 MHz). Besides, the as‐prepared FCPIs also possess excellent thermal property of which FCPI‐0.3 exhibited the 5% weight loss temperature of 540°C and the glass transition temperature is also as high as 385°C. Furthermore, the tensile strength of the film is 127 MPa, the elongation at break is around 15.82%, and the Youngs' modulus is about 3.10 GPa proving the superior mechanical property. As a result, the successful preparation of the FCPI nanocomposites not only possess low‐temperature curing and low‐dielectric performance but also exhibit excellent thermal and mechanical properties, which shows a wide range of application prospects in the field of microelectronics for the advanced electronic package.

Pure and mixed-mode (I/III) fracture toughness of preplaced aggregate fibrous concrete and slurry infiltrated fibre concrete and hybrid combination comprising nano carbon tubes

Concrete is the most widely used and inexpensive material in the construction sector. However, due to its weakness in tension, the cracking and brittle fracturing of concrete is considered a major deficiency. Advancements in fibrous concretes have recently been emerged to mitigate this issue. Preplaced Aggregate Fibrous Concrete (PAFC) and Slurry Infiltrated Fibrous Concrete (SIFCON) are unique cement composites made of fibres with surpassing mechanical properties and exceptional toughness values. The production of PAFC and SIFCON involves packing of aggregates and fibres in the mould and filling the gaps between the aggregates with the high flowability injected cement grout. Nevertheless, the mono and hybrid layered effect of PAFC and SIFCON on fracture toughness is still unexplored and needs special attention to bridge this research gap. This research examined the pure (I and III) and mixed (I/III) modes of fracture toughness of PAFC, SIFCON and hybrid two-layered PAFC-SIFCON samples. For this purpose, many notched specimens of circular disc shapes were prepared using single and double-layer concepts. To investigate the effect of fibres, three different fibre types were used; hooked-end steel fibre, macro polypropylene fibre and hybrid shape of crimped-hooked end steel fibre with dosages of 2.4% and 8% by volume to produce PAFC and SIFCON, respectively. Additionally, multi-walled nano-carbon tubes (MWCNT) were added to the composites with a dosage of 0.1% by cement weight. The compressive strength, stress intensity factors, effective stress intensity factors, mixity parameter, failure pattern, range of fracture toughness and scanning electron microscope were examined, discussed, and compared. Results indicated that pure mode III has a greater cracking risk than both mode I and mixed-mode I/III. The mixed-mode fracture toughness of PAFC specimens improved by 33.07 to 67.94%. Similarly, this improvement ranged from 59.77 to 210.70% for SIFCON and from 51.0 to 131.55% for PAFC-SIFCON. In addition, the fracture toughness of SIFCON is considerably higher than the PAFC and hybrid combination. In all three composite types, the hybrid shape steel fibre outperformed the hooked-end steel and polypropylene fibre under all three modes.

Comparative Life Cycle Assessment of the Manufacturing of Conventional and Innovative Aerators: A Case Study in China

China aims to achieve a 50% rate of mechanization for aquaculture by 2025. Aerators are crucial mechanical equipment in aquaculture for increasing yield, but their manufacturing has an environmental impact. Improving the yield and controlling the environmental impacts of aerators in China is an important issue have to be considered, as is comparing the environmental impact of manufacturing innovative and conventional aerators. Herein, life cycle assessment (LCA) as a quantitative analysis method was used, and six models of three widely used aerators (impeller, paddle wheel, and wave) were selected as an example to compare the environmental impacts of conventional and innovative aerators from large-scale aerator manufacturing enterprises in Taizhou, China. The results showed that the conventional paddle wheel aerator (SC-1.5) had the largest environmental impact, while the innovative paddle wheel aerator (GSC-1.5) had the lowest environmental impact, reduced by 30%. In addition, the environmental impact of the innovative impeller aerator (SYL-1.5) and wave aerator (GYL-1.5) was less than that of the conventional impeller aerator (YL-1.5) wave aerator (SW-1.5), but only by 0.21% and 0.02%, respectively. Human toxic potential (HTP) made the largest contribution, and the manufacturing of copper wire was critical; the environmental impact was from 96.50% to 98.21% for all material inputs. The contributions of iron and stainless steel were 1.05–1.28% and 0.74–1.04%, respectively. Therefore, conductive materials with excellent environmental performance, such as carbon nanomaterials and nano copper wire, should replace copper wire in aerator manufacturing. The results expand aquaculture life cycle knowledge and could reduce the environmental impacts of aerator manufacturing in China.

Effects of Different Carbon Types on the Growth and Chromium Accumulation of Peach Trees under Chromium Stress

Heavy metal pollution in agricultural soil is a serious problem, which threatens the environment and human safety. In this study, the effects of biochar (BC), activated carbon (AC), and nanocarbon (NC) on the growth of peach trees under chromium (Cr) stress were investigated through pot experiments. The experimental results showed that under Cr stress, BC, AC, and NC could increase the soil nutrient content and enhance the soil enzyme activity. Moreover, all carbon forms promoted the conversion of Cr speciation; decreased the content of exchangeable (EXE), carbonate-bound (CARB), and iron–manganese-oxide-bound (FeMnO) Cr in the soil; increased the organic-bound (Org) and precipitated (Pre) Cr content; and reduced Cr availability. After BC, AC, and NC treatment, the content of Org-Cr in the soil increased by 86.05%, 72.97%, and 65.02%; the content of EXE-Cr decreased by 75.30%, 75.33%, and 73.10% compared with the control under severe Cr treatment, respectively. Moreover, the accumulation of Cr in plants decreased by 29.70%, 22.07%, and 20.52%, respectively. At the same time, these three carbons reduced the accumulation of Cr in various parts of the peach tree, alleviated the oxidative damage caused by Cr stress, effectively protected the photosystem of the leaves, improved the photosynthetic capacity, and promoted the growth of the peach tree. Compared with the control, the dry matter accumulation increased by 20.81%, 9.54%, and 6.95% with BC, AC, and NC treatment under severe Cr treatment. Therefore, BC, AC, and NC can all effectively alleviate soil Cr toxicity, and BC has the best effect, which can be popularized in production.

Electrochemical and spectroscopic evaluation of 6-MP and its interaction with carbon dots and dsDNA

The 6-Mercaptopurine (6-MP) is an anti-cancer drug used for the treatment of acute lymphocytic leukaemia. Electrochemical signal of 6-MP over the unmodified Glassy carbon electrode (GCE) is poor and not suitable to probe the molecule through electrochemical measurements. In order to enhance the electrochemical signal from the molecule, the substrate has been fabricated by electrodepositing gold nano particles (AuNPs) on the surface of GCE. The electrochemical signal of 6-MP has been enhanced significantly over the modified substrate. The peak current of 6-MP obtained as a result of the electrochemical oxidation increases with subsequent addition of carbon nano dots (CD) in the solution, which revealed the strong interaction between the 6-MP with CD. The interaction between 6-MP and CD is established using UV–vis spectroscopy and fluorescence spectroscopy. The intensity of fluorescence of CD is quenched on interaction with 6-MP in the solution, strong quenching constant value beyond the diffusion-controlled limit, indicates stronger interaction between 6-MP and CD. Atomic force microscopy (AFM) investigations imaged the change of the texture of dsDNA upon its interaction with 6-MP.

Fabrication of modified carbon nano tubes based composite using ionic liquid for phenol removal

Carbon nano tubes are functionalized to enhance their surface properties and target specificity. In this research, a novel ionic liquid functionalized carbon nanotube (IL-CNT) material was synthesized using 1-Hexyl-3-methylimidazolium bis(trifluormethylsulfonyl)imide and investigated for the phenol removal. The parametric experiments were performed to identify the optimal conditions for high removal performance. With an initial concentration of 50 mg/L and an IL-CNT dosage level 100 mg, 95.36% phenol removal was attained at optimal pH 6.0. The occurrence of monolayer attachment was verified through equilibrium studies. The Langmuir isotherm parameters are evaluated as qm =109.9 mg/g and KL = 0.196 L/mg. The kinetic experiments followed Pseudo Second Order model (R2 > 0.990). The synthesized nanomaterial was characterized using Scanning Electron Microscopic imaging, Fourier Transform Infra-Red spectra, X-Ray Diffraction analysis and Thermo Gravimetric Analysis.

Vibrational characteristics of fastening of a spherical shell with a coupled conical-conical shells strengthened with nanocomposite sandwiches contained agglomerated CNT face layers and GNP core under spring boundary conditions

The following paper is prepared to compute the Natural Frequency Parameters (NFPs) linked to the Fastened Spherical-Conical-Conical Shell (FSCCS) structures composted of Nanocomposite Sandwich (NS) materials under the effects of springs as Boundary Conditions (BCs). To explain, the NS material implemented here is made of three layers covering Top Face Layer (TFL), Bottom Face Layer (BFL), and Core Layer (CL). In addition, the TFL and BFL are composed of Carbon Nano Tube (CNT) nano-fillers with agglomeration characteristics, while the CL benefits from Graphene Nano Platelet (GNP) nano-materials. For more information, the mechanical values related to the Agglomerated Carbon Nano-Tube Nanocomposite (ACNTN) material composer the TFL and BFL (ACNTN-TFL and ACNTN-BFL) are carried out by the Eshelby-Mori-Tanaka Approach (EMTA). At the same time, the Halpin-Tsai Approach (HTA) is used to extract these values for GNP-CL. To add more, four different sandwich models are implemented by considering the compatibility between layers. Moreover, the First Order Shear Deformation Theory (FOSDT) and Donnell's Shell Theory (DST) are exploited to obtain the primary relationships of the FSCCS segments. Hamilton's strategy is also operated to derive the Governing Differential Equations (GDEs) of the FSCCS's components. Further, the well-systematized computational meshless method tagged the Generalized Differential Quadrature (GDQ) program is carried out to discrete the GDEs coupled with the structure's segments. Furthermore, the calculation of the eigenvalues is implemented to compute the NFPs of the FSCCS structure. After that, to credit the submitted program, the outputs related to the FSCCS calculated by the present framework are analogized with the responses linked to the FE-based commercial software. In the last, multiple examples are styled and computed to point to the influences of the different material, geometric, and BCs forms on the NFPs of the NS-FSCCS structures, including 12 different geometry types related to the NS-FSCCS.

Constructing conductive network using 1D and 2D conductive fillers in porous poly(aryl ether nitrile) for EMI shielding

Electromagnetic interference shielding materials with high shielding effectiveness, light weight, and good heat resistance are desperately needed in areas of aerospace, aircraft, and automobiles. Herein, lightweight porous composites foams with satisfactory electromagnetic interference shielding effectiveness (EMI SE) and mechanical strength was prepared using 1D, 2D conductive fillers and poly(aryl ether nitrile) (PEN) by adapting non-solvent induced phase separation (NIP). It is found that the introduction of 1D and 2D conductive fillers could interweave to form conductive network more easily than the presence of 2D conductive filler alone. The EMI SE of 25.8 dB could be reached for composite foam with 5 wt% of graphene and 3 wt% of carbon nano tubes (PEN/5G3C) and the EMI shielding is dominated by absorption attenuation, with PEN/5G3C shows absorption ratio near 90% in the X-band range, which is believed to be attributed to the multiple internal reflection and absorption inside the conductive foam. Moreover, the network of fillers could strongly interact with the polymer matrix and enhance the tensile strength of the porous foams. The tensile strength of PEN/5G3C reached 4.14 MPa, which is 218% higher than that of neat PEN foam. Due to the high thermal resistance (Tg of 256.4 °C), low density (< 0.2 g/cm3) and satisfactory EMI SE, the composite foam based on PEN show great potential as the next-generation high-performance EMI shielding materials.

Phase engineering of vanadium sulfides as superior anodes for high-energy density sodium-ion half/full batteries

The development of electrode materials for Sodium-Ion Batteries (SIBs) has received more and more attention. Among them, vanadium sulfide, as a member of the transition metal sulfide family, owns the characteristics of rich electrochemical activity, high theoretical capacity and adjustable spatial structure. However, the complicated synthetic process, poor rate capability and intricate redox mechanism of vanadium sulfides make them less competitive for commercial use. In this work, a facile approach based on the ball-milling technique followed by adjusted annealing temperature is introduced to fabricate large-scale vanadium sulfides. This general phase-controlled method can bring three different crystal types of V5S8, V3S4 and V3S5. With homogeneous covering of super P and Carbon Nano Tubes (CNTs), a conductive network that favors the Na ions/electrons transport in the vanadium sulfides-based electrodes can be fabricated. The V5S8 exhibits the best performance in SIBs with specific capacity of 918 mAh g−1 at 0.1 A g−1 (100 cycles). Moreover, V5S8 electrode also exhibits an ultra-rate capability of 333 mAh g−1 at 50 A g−1 after cycling lifespan (4000 loops). The extremely high pseudo-capacitance characteristics of V5S8 is significant during the SIBs discharge/charge. Additionally, the V5S8 anode also shows the high energy density of 165 Wh kg−1 in SIBs full cell.

Developing a high-performance aqueous zinc battery with Zn2+ pre-intercalated V3O7·H2O cathode coupled with surface engineered metallic zinc anode

• Zn 2+ intercalation capacity in V 3 O 7 ,nH 2 O could be significantly increased with Zn(II) chemical preinsertion. • Nanocarbon derived from candle shoot has been employed as artificial SEI to protect metallic Zn anode. • Nano carbon as SEI reduce the Zn 2+ plating/stripping overpotential and regulates dendrite less Zn 2+ plating. • C@Zn//Zn-V 3 O 7 ·H 2 O full cell showed improved cycling performance over Zn//Zn-V 3 O 7 ,nH 2 O. Herein we demonstrate a high-performance full cell aqueous zinc ion battery with structurally engineered V 3 O 7 ·H 2 O cathode and surface modified metallic zinc anode. We demonstrate that the capacity, rate performance and stability of V 3 O 7 ·H 2 O cathode can be significantly improved via Zn 2+ pre-intercalation, which acts as a pillaring agent to stabilize the cathode against structural degradation. The pre-intercalated V 3 O 7 ·H 2 O cathode showed an improved specific capacity (404 mAh/g at 0.1 A/g) and rate capability (235 mAh/g at 2 A/g), which was much higher than the pristine V 3 O 7 ·H 2 O, which showed specific capacity of 316 mAh/g and 141 mAh/g at 0.1 A/g and 2 A/g, respectively. Further we demonstrate that the Zn 2+ plating stripping overpotential and the uncontrollable dendrite growth at the metallic zinc anode can be significantly reduced with surface engineering of metallic zinc with a thin layer of carbon coating. We followed a simple and economical approach to obtain the nanocarbon from candle shoot, which could be coated uniformly onto the metallic zinc with controllable thickness. We demonstrate the efficacy of the C@Zn as anode by coupling it with both Zn-V 3 O 7 ·H 2 O and V 3 O 7 ·H 2 O cathode, which showed much improved cycling stability compared to that of unprotected metallic zinc.

Brittle star-like nanoweb modified carbon cloth synthesized by self-templated hollow zeolitic imidazolate framework-8 for stable Li metal anodes

Li metal anode possesses the highest energy density among all anode candidates, but the dendrite growth impedes its application. Herein, a carbon cloth-assisted two-step self-template method was introduced to the synthesis of hollow zeolitic imidazolate framework-8, which exhibited a brittle star-like ZnO–N co-doped nano carbon web after annealing and acted as a promising stable Li metal anode (h-ZNCC-Li). The ZnO and N species are lithiophilic spots, which lead to a 4100 h stable Li plating/stripping process at a high current density and capacity of 10 mA/cm2 and 10 mAh/cm2, respectively. Moreover, at the end of the cycling, the brittle star-like h-ZNCC-Li anode displays a low-voltage hysteresis of 68 mV. The apparent chemical diffusion coefficient was calculated based on the impedance and cyclic voltammetry supporting the rapid diffusion mechanism. This work develops a unique and effective strategy of hollow metal-organic framework-derived carbon for lithium metal anode.

Bimetal Decorated Carbon Nano Materials (CNMs) Synthesized from Plant Waste Materials as An Excellent Hydrogen Storage Material

Abstract: In this study, Carbon nanomaterials (CNMs) were synthesized from plant filaments and were investigated for the hydrogen adsorption capacity. Synthesis was carried out using Bagasse-a plant waste materials by pyrolyzing at high temperature of 700℃ in an inert atmosphere and were activated by different alkali solutions. The activated carbon fibres were further loaded with nano size bimetal particles. The SEM images show highly porous carbon nano structures impregnated with different combinations of metals. The EDAX and SEM confirmed the presence of bimetals. Raman spectra and X-ray diffraction indicates the presence of crystalline and amorphous carbon material. The designed carbon nanomaterial with bimetal particles has the higher specific surface area (SSA) than the carbon obtained without activation which was confirmed by the BET analysis. This makes it a front runner for its utilization in hydrogen adsorption among numerous others. The adsorption was studied using a Sievert’s apparatus

EIS and Electrical Investigations on (1D) Multiwall Carbon Nanotubes as NAM Additive for Automotive Lead-Acid Battery

Currently, an application like Start-Light-Ignition (SLI) for the automotive industry prefers flooded type lead-acid energy storage and is also vastly adopted energy storage. Lead-acid cells in a battery comprise negative and positive electrodes, separated by an insulating material with industrial-grade H2SO4 as an electrolyte. The objective of the present investigation is to overcome the progressive sulphation in the negative electrode and improve the battery’s electrical performance. With one dimensional (1D) carbon nano tubes (CNTs) as an additive in the negative electrode of an automotive flooded lead-acid battery (LAB), we try to improve the battery performance. In this study, negative electrodes of LAB were prepared by loading traditional constituents like lead oxide, H2SO4, H2O, polyester binder, lignosulphonate, and Blanc Fixe while limiting MWCNTs to 0.2%. The performance studies of the prepared batteries were conducted, as per Japanese Industrial Standards (JIS). Both the batteries prepared with and without MWCNTs as an additive in negative active materials (NAM) were subjected to electrical assessments to understand the cold cranking ability, cycling stability, and charge acceptance. The batteries were also analyzed by electrochemical impedance spectroscopy (EIS) where the lower charge transfer resistance was observed with the battery having MWCNTs when compared to the control (without MWCNTs) battery. The present investigations established that the MWCNT material, as an additive, played a vital role in laying an improved conductive network across the negative electrodes for higher cycling applications (ISS/Hybrid/EV).

Preparation of carbon - based nanocomposites and their application in the anode of lithium ion batteries

At present, with the increasing demand for electronic products, accompanied by the rise of new energy vehicles, the application of lithium-ion batteries in life is gradually popular. Used for commercial purposes of lithium battery cathode on the characteristic with non-toxic cut the advantage of cost control more successful, but its development in the future have received the restrictions in terms of the specific capacity, so using carbon nano composite material has become the new direction for the future development of lithium ion battery cathode, this article will also with its as the research direction for research.

Environmental remediation of selenium using surface modified carbon nano tubes - Characterization, influence of variables, equilibrium and kinetic analysis

Selenium is targeted as a priority pollutant to be removed due to its high toxicity level and lethal effects. In this research, a novel nano sorbent was fabricated using ionic liquid on multiwalled carbon nanotubes (IL-MCNT) and employed for Selenium remediation from aqueous media. Besides solution pH, nanocomposite dosage, the initial selenium concentration, temperature and sorption time were also examined as operating variables. At optimal pH 2.0, 96% of the selenium was removed with maximum efficiency with 100 mg/L of IL-MCNT at 308 K, 45 min of contact time, and 110 g of IL-MCNT dosage. From kinetic studies, it appears that the Langmuir isotherm fits the observed data (R2 > 0.9813), supporting the hypothesis that monolayer attachment occurs. The Langmuir isotherm parameters are evaluated as qm = 125 mg/g and KL = 0.172 L/mg. As a result of testing several kinetic models, the pseudo-second-order model was the most suitable for experimental data (R2 > 0.9746). Scanning Electron Microscopy images, FTIR spectra, and thermogravimetric study were used to examine the synthesized nanomaterial.

A green extraction process of nanocarbon dots from prawn shells, and its reinforcement in epoxy polymers

AbstractExoskeletons of prawn, shrimp, and crab discarded as waste are rich sources of inorganic and organic materials. Currently, these discards are mainly utilized for the extraction of chitin and less attention is paid to the recovery of other organic constituents present in the exoskeletons. The present study aimed to synthesize nano carbon dot (CD) and chitin from prawn shell, and utilization of CD as an additive to epoxy polymers to obtain a corrosion resistant polymer coating. Nano CDs were synthesized through a hydrothermal carbonization process and the characteristics were evaluated using spectrophotometric, fluorescence, and Fourier transform infrared spectroscopy studies. The CD reinforced bisphenol epoxy polymer composite coated over boat building steel exhibited the least defect, which in turn imparted the highest polarization resistance with the lowest capacitance. Chemical and morphological data of epoxy polymer composite highlighted the interaction of NH2 present in CD with polymer matrix. The functional group NH2 from CD synergistically acted along with hardener to form a pore free epoxy coating. Hydrothermal process of prawn shell enabled to extract chitin as evidenced by their spectral signature peaks. This study gave two economically important products through a green synthesis protocol.