Utilization Of Such Materials Research Articles

Leveraging Non-Radiative Transitions in Asphaltenes-Derived Carbon Dots for Cancer Photothermal Therapy.

Cancer photothermal therapy leverages the capability of photothermal agents to convert light to heat for cancer cell ablation and necrosis. However, most conventional photothermal agents (Au, CuS, Pd, mesoporous silica nanoparticles, and indocyanine green dye) either face scalability challenges or photobleached upon prolonged irradiation which jeopardizes practical applications. Here, asphaltenes-derived carbon dots (ACDs, 5nm) are rationally engineered as a low-cost and photostable photothermal agent with negligible in vivo cytotoxicity. The abundant water-solvating functional groups on the ACDs surface endows them with excellent water re-dispersibility that outperforms those of most commercial nanomaterials. Photothermal therapeutic property of the ACDs is mechanistically described by non-radiative transitions of excited electrons at 808nm via internal conversions and vibrational relaxations. Consequently, the ACDs offer cancer photothermal therapy in mice within 15 days post-exposure to one-time near infrared irradiation. This pioneering study showcases the first utilization of asphaltenes-based materials for cancer therapy and is expected to arouse further utilization of such materials in various cancer theranostics.

Independent enhancement of the in-plane Seebeck effect in 2D PtSe2/PtSe2 homostructures via a facile interface tuning method

Atomically thin two-dimensional (2D) transition-metal dichalcogenide (TMDC) films have emerged as promising semiconducting materials for use in thermoelectric (TE) applications. However, the utilization of such materials remains challenging owing to the relatively high intrinsic resistance as the size of the TMDC thin films increases to the centimeter scale. These 2D TMDC films can also form vertically stacked homo- or heterostructures at large interfaces with other 2D TMDC films, resulting in unique TE properties at room temperature. This article reports on the in-plane TE properties when the interfaces formed within a PtSe2/PtSe2 (3 nm/3 nm) homostructure are modulated as a function of O2 plasma treatment time. The results show enhanced Seebeck coefficients compared with that of the single-layer PtSe2 with the same thickness. The independent enhancement in the Seebeck coefficient while keeping the electrical conductivity leads to a substantial increase in the power factor. Such extra Seebeck voltage in 2D PtSe2/PtSe2 homostructures is mainly as a result of momentum exchange by charge carriers caused by the temperature gradient in the vertical direction, which occurs in-plane Seebeck coefficient measurements, at the interface between the PtSe2 layers in the in-plane temperature gradient along the samples. These results resemble the characteristics of the phonon drag effect at low temperatures, which can independently increase the Seebeck coefficient at room temperature.

Efficient symmetric supercapacitors employing molecular engineered pyrazine functionalized perylene diimide electrode materials

Redox active small organic molecules (OM) are the promising materials for energy storage applications. The practical utilization of such materials in combination with excellent redox-active material is advantageous to enhance the specific capacitance (Csp). Herein, naphthalene diimide (NDI) and perylenediimide (PDI) molecules linked with pyrazine (Pyr) are exploited as faradiac reversible redox-active material on graphite foil (GF) surface to act as electrode materials in supercapacitor (SC) device. The as-fabricated NDI-Pyr/GF and PDI-Pyr/GF electrodes were optimized in three-electrode SC device in view of their electrochemical performance. The NDI-Pyr/GF and PDI-Pyr/GF in SC device demonstrated a Csp of about 260 and 302 F g−1, respectively at 0.5 A g−1 current density. However, in two-electrode symmetric supercapacitor (SSC) device i.e. PDI-Pyr/GF//PDI-Pyr/GF exhibited excellent Csp of about 192 F g−1 at 1 A g−1 current density with longer cycling stability with 88.13% after 4000 galvanostatic (GCD) charge/discharge cycles. Furthermore, an excellent energy density of 54 Wh kg−1 at a power density of 2700 W kg−1 is provided by the SSC device. These results suggest that the as-prepared PDI-Pyr/GF//PDI-Pyr/GF have practical energy storage application in OSC devices.

Investigation and Optimization on Use of Wood Ash as partial Cement Replacement in Cement Mortar

Abstract: Management of solid waste is the major concern globally due to increasing quantities of waste materials and byproducts from industries. Lack of space availability for land filling and because of its increasing cost, utilization and recycling of industrial by- products and waste materials has the only option as it is economical and eco friendly. There are several types of such materials, which can be recycled or reused in construction. The utilization of such materials in construction not only makes it economical, but also helps in reducing disposal problems. One such material is wood ash (WA). Wood ash (WA) is the residue generated due to combustion or incineration of wood and wood products (chips, saw dust, bark, etc.).The XRD (X-RAY DIFFRACTION) test results, SEM (scanning electron microscope) analysis and chemical analysis of WA showed that it contains amorphous silica and thus can be used as cement replacing material. Many researches had been carried out to incorporate wood waste ash as a cement replacement material in the production of greener construction material (concrete/mortar) and also as a sustainable means of disposal for wood waste ash. Results of these researches indicated that wood waste ash can be effectively used as a cement replacement material for the production of structural concrete/mortar of acceptable strength and durability parameters.

Sustainable preparation of oxidized graphitic material from wheat straw using a deep eutectic solvent for superactivity of cellulase

Relatively greener methods for the direct and single-step conversion of abundantly available biomass into an oxidized graphitic material should be developed for promoting the utilization of such materials in different applications.

Charged hybrid block copolymer-lipid-cholesterol vesicles: pH, ionic environment, and composition dependence of phase transitions

The impacts of pH, salt concentration (expressed as Debye length), and composition on the phase behavior of hybrid block copolymer-lipid-cholesterol bilayers incorporating carboxyl-terminated poly(butadiene)-block-poly(ethylene oxide) copolymer (PBdPEO1800(−)) or/and non-carboxyl-terminated PBdPEO (PBdPEO1800 or/and PBdPEO950), egg sphingomyelin (egg SM), and cholesterol were examined using fluorescence spectroscopy of laurdan. Laurdan emission spectra were decomposed into three lognormal curves as functions of energy. The ratio of the area of the mid-energy peak to the sum of the areas of all three peaks was evaluated as vesicles were cooled, yielding temperature breakpoint values (Tbreak) expected to be within the range of the phase transition temperature. Tbreak values displayed dependence on pH, Debye length, and vesicle composition consistent with an electrostatic repulsion contribution to vesicle phase behavior. Increased pH and Debye length, for which a greater dissociated fraction of PBdPEO1800(−) and a greater energy of electrostatic repulsion would be expected, resulted in Tbreak values as much as 10 °C less than at low pH or short Debye lengths. Additionally, at Debye lengths comparable to those at physiologically relevant ionic strength, Tbreak at pH 5.9 was observed to be slightly higher than at pH 7.0 for vesicles containing 50 mol% PBdPEO1800(−). Electrostatic effects observed for hybrid vesicles incorporating significant amounts of carboxyl-terminated polymer may have the ability to drive phase separation in response to pH drops—such as those observed after endocytosis—in physiologically relevant conditions, suggesting the utility of such materials for drug delivery.

Topological phase singularities in atomically thin high-refractive-index materials

Atomically thin transition metal dichalcogenides (TMDCs) present a promising platform for numerous photonic applications due to excitonic spectral features, possibility to tune their constants by external gating, doping, or light, and mechanical stability. Utilization of such materials for sensing or optical modulation purposes would require a clever optical design, as by itself the 2D materials can offer only a small optical phase delay – consequence of the atomic thickness. To address this issue, we combine films of 2D semiconductors which exhibit excitonic lines with the Fabry-Perot resonators of the standard commercial SiO2/Si substrate, in order to realize topological phase singularities in reflection. Around these singularities, reflection spectra demonstrate rapid phase changes while the structure behaves as a perfect absorber. Furthermore, we demonstrate that such topological phase singularities are ubiquitous for the entire class of atomically thin TMDCs and other high-refractive-index materials, making it a powerful tool for phase engineering in flat optics. As a practical demonstration, we employ PdSe2 topological phase singularities for a refractive index sensor and demonstrate its superior phase sensitivity compared to typical surface plasmon resonance sensors.

Test on Concrete after Adding Foundry Sand

Abstract: Due to ever increasing quantities of waste materials and industrial by-products, solid waste management is the prime concern in the world. Scarcity of land-filling space and because of its ever increasing cost, recycling and utilization of industrial by-products and waste materials has become an attractive proposition to disposal. There are several types of industrial byproducts and waste materials. The utilization of such materials in concrete not only makes it economical, but also helps in reducing disposal concerns. One such industrial by-product is Waste Foundry Sand (SFS). WFS is major byproduct of metal casting industry and successfully used as a land filling material for many years. But use of waste foundry sand (WFS) for land filling is becoming a problem due to rapid increase in disposal cost. In an effort to use the WFS in construction materials, research has being carried out for its possible utilization in making concrete as partial replacement of fine aggregate. In India, approximately 1.71 million tons of waste foundry sand and in Punjab region, approximately 0.17 million tons of waste foundry is produced yearly. This experimental investigation was performed to evaluate the strength and durability properties of M20 (30 MPa) and M30 (40 MPa) grades of concrete mixes, in which natural sand was partial replaced with waste foundry sand (WFS). Natural sand was replaced with five percentage (0%, 5%, 10%, 15%, 20%) of WFS by weight. A total of ten concrete mix proportions M-1, M-2, M- 3, M-4 and M-5 for M20 grade of concrete and M-6, M-7, M-8, M-9 and M-10 for M30 grade of concrete with and without WFS were developed. Compression test, splitting tensile strength test and modulus of elasticity were carried out to evaluate the strength properties of concrete at the age of 7, 28, 91 and 365 days. In non destructive testing, rebound hammer and ultrasonic pulse velocity test were conducted at the age of 28, 91 and 365 days. In case of durability property, abrasion resistance, rapid Chloride Permeability and deicing salt scaling resistance was evaluated at the age of 28, 91 and 365 days. Statistical analysis and comparative study between strength and durability properties of both grade of concrete (M20 and M30) were carried out at the age of 28, 91 and 365 days. XRD study was done to identify the presence of various compounds in M20 grade of concrete with foundry sand in varying percentages replacement of fine aggregate.

Mechanical Properties of Soft Rocks Subjected to Water‐Rock Reaction and Cyclic Pressure

Studying the mechanical properties of soft rocks subjected to water and cyclic loading would contribute to a better understanding of the stability analysis of soft rock engineering under the conditions of storm and carrier dynamics. In this paper, two soft rocks from Southwest China (i.e., muddy siltstone and silty mudstone) were selected as test samples. Uniaxial compressive tests were applied to investigate the strength and deformation characteristics under water‐rock reactions. Meanwhile, triaxial tests were carried out to analyse the fatigue damage and failure characteristics by applying cyclic axial loading under different confining pressures. The results indicated a reduction in the uniaxial compressive strength (UCS) under saturated conditions, which is correlated with the disintegration resistance of soft rocks. Moreover, the samples exhibited a softening phenomenon due to water absorption and rock expansion, decreasing the elastic modulus. The triaxial tests demonstrated that axial strain accumulated with the number of loading cycles due to fatigue and even failed when applying increased cyclic loading with certain cycles. The cohesion decreased during cyclic loading, but the friction angle was relatively independent of the number of cycles. In addition, reductions in the dynamic elastic modulus and shear modulus decreased with increasing loading time. This study indicated that water and cyclic loadings could cause significant degradation of the strength and stiffness of soft rocks, which need to be considered carefully during the engineering utilization of such materials.

Utilization of Marble Wastes in Clay Bricks: A Step towards Lightweight Energy Efficient Construction Materials

Marble dust is one of the hazardous byproducts of marble-processing factories and requires planned disposal. Its beneficial use as a construction material will add to the sustainability, and most importantly, might overcome the burden of marble waste disposal. However, the use of marble dust in concrete has a negative impact. Therefore, this research examines various properties related to the utilization of such material in ceramic clay, and therefore its effects on the use of clay bricks are investigated. The research activity covers the categorization of marble dust powder from three different sources: Ziarat in Mohmand Agency, Buneer, and Mullagori (Pakistan). Its utilization in different proportions preparation of bricks is also addressed. Through the partial replacement of clay with marble dust from 0 to 30% by weight with amplification of 5%, seven mix designs are examined. The test result includes Bulk density, water absorption, porosity, thermal insulation, and strength. The partial replacement of clay with marble dust reduced its weight, strength and increased its porosity, water absorption, and thermal insulation. Furthermore, the utilization of marble powder in bricks minimizes soil erosion and reduces pollution to the environment. Doi: 10.28991/cej-2021-03091738 Full Text: PDF

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.

Synthesis of near-infrared-emitting type-II In(Zn)P/ZnTe (core/shell) quantum dots

InP-based quantum dots (QDs) are considered promising candidates for replacing Cd-based QDs and ideal light emitters for next-generation displays. However, their spectral windows are confined to visible wavelengths, which restricts their applicability beyond displays. Thus, non-toxic colloidal QDs with the potential to extend the spectral window are highly desirable for many practical applications. Here, near-infrared-emitting type-II In(Zn)P/ZnTe (core/shell) QD heterostructures are fabricated. As the ZnTe shell grows on an In(Zn)P QD core, the absorption band redshifts owing to the decreased optical band gap. Near-infrared photoluminescent (PL) emission by type-II In(Zn)P/ZnTe (core/shell) QDs is realized by introducing an outer shell comprising ZnSeS passivation layers. The PL emission range of the resulting type-II In(Zn)P/ZnTe/ZnSeS (core/shell/shell) QDs can be tuned by varying the In(Zn)P core diameter and ZnTe shell thickness. Meanwhile, the proposed QDs also exhibit a prolonged exciton lifetime of 387 ns indicates the type-II characteristics. Moreover, the ZnSeS passivation layers enable surface modification while preserving the optical and chemical stabilities, resulting in water-soluble QDs. Importantly, heavy-metal-free near-infrared-emitting type-II In(Zn)P/ZnTe (core/shell) QDs have immense potential to increase the utilization of such materials in biomedical and energy applications requiring nontoxicity and near-infrared emission.

Photochemical C-H Activation Enables Nickel-Catalyzed Olefin Dicarbofunctionalization.

Alkenes, ethers, and alcohols account for a significant percentage of bulk reagents available to the chemistry community. The petrochemical, pharmaceutical, and agrochemical industries each consume gigagrams of these materials as fuels and solvents each year. However, the utilization of such materials as building blocks for the construction of complex small molecules is limited by the necessity of prefunctionalization to achieve chemoselective reactivity. Herein, we report the implementation of efficient, sustainable, diaryl ketone hydrogen-atom transfer (HAT) catalysis to activate native C-H bonds for multicomponent dicarbofunctionalization of alkenes. The ability to forge new carbon-carbon bonds between reagents typically viewed as commodity solvents provides a new, more atom-economic outlook for organic synthesis. Through detailed experimental and computational investigation, the critical effect of hydrogen bonding on the reactivity of this transformation was uncovered.

Severe plastic deformation of tubular materials – Process methodology and its influence on mechanical properties – A review

Severe Plastic Deformation (SPD) processes bring about phenomenal grain refinement, by imparting plastic strain onto the materials being processed, owing to which significant improvements in mechanical properties are brought about. While plenty of processes exist for processing bulk materials, the direct utilization of such materials is very limited. Tubular materials buy enlarge are some of the most widely used form of industrial products and this work reviews the SPD techniques that are available for processing tubular materials. Considering the extent to which tubular materials are used, the lack of wide range of SPD techniques to process them is very unfortunate. A systematic review of process methodology of these SPD techniques which process tubular materials and the impact of such processing on mechanical properties of the materials is made. The review is aimed at providing the readers with a design thinking that would enable the readers to adopt the SPD techniques that they are familiar with into something that would process tubular materials. SPD processed tubes, with strengthened walls, of course could have a reduced thickness amounting to materials savings. Such savings would not only result in cost savings but also would lead to sustainability.

Effect of Soil Organic Matters in Dredged Soils to Utilization of their Mixtures Made with a Steel Slag.

Dredged soils have been used as construction materials by alkaline activation with steel slag (steel slag-dredged soil mixtures) at harbors. Such mixtures develop strength chiefly by calcium silicate hydrate (C-S-H) formation by the pozzolanic reaction. However, the strength of such mixtures is unpredictable, and in some cases, mixtures have been too soft for the intended engineering application. An identification of strength development indicators would accelerate evaluation processes for strength development to facilitate and promote the utilization of such materials. This paper focuses on the relationship between the characteristics of soil organic matters in dredged soils and the strength development of the mixtures by a comparison of eight dredged soils collected from eight different Japanese harbors. The characteristics of the soil organic matters were identified to determine as indicators of mixtures with weak strength development, i.e., enriched sulfur content in extracted soil organic matter (humic acid) fraction, and the N/C ratio of humic acid similar to land humic acid standards. Increases in the validated fraction of dredged soils and steel slag by replacing fractions disadvantageous to construction resources would contribute to reduce waste production, which would lower the environmental impact of the use, aiming to achieve sustainable utilization of such materials.

Shear capacity of masonry walls externally strengthened using Flax-TRM composite systems: experimental tests and comparative assessment

A growing environmental awareness is gradually changing the entire economic system and consequently, the building materials sector is increasingly interested in innovative sustainable solutions. The use of plant fibres as reinforcement in inorganic composite systems, generally referred to as Textile Reinforced Mortar (TRM), represents an innovative alternative to the use of more traditional high-strength inorganic fibres, which reduces the environmental impact of the composite. However, there are several unsolved issues regarding the correct mechanical behaviour of such innovative systems. Various studies have been conducted to assess the fibre-to-mortar bond properties and to investigate the tensile behaviour of TRMs based on plant textiles, such as flax, hemp, coir, sisal, and jute. Moreover, there is still a lack of experimental evidence concerning the efficiency of the composite material once applied to structural elements. Therefore, this paper reports on an experimental study on the shear capacity of walls strengthened by two TRMs characterised by a different amount of textile reinforcement. The experimental results are discussed and compared with the results of theoretical models derived from formulations proposed by the standards in this field. This study shows that Flax-TRM reinforcement enhances the strength and ductility of a masonry assemblage, confirming the potential utility of such materials. Furthermore, it points out some limitations of this reinforcement technique and paves the way for future studies aimed at improving the efficiency of the entire system.

Effect of pozzolanic materials in geopolymer mortar using industrial waste material

Geopolymer is one of the new binder technology in the construction where cement is replaced fully by pozzolanic materials such as fly ash, GGBS and alkaline solution. This control the emission of CO2 produced from the cement manufacturing industries. The industrial waste requires disposal is the major problem by utilization of such materials in geopolymer for the benefits of the environmental and eco-friendly process. In this paper, the effect of pozzolanic material in geopolymer mortar using industrial waste material based on oven heating. The optimum percentages of low calcium class F fly ash and GGBS is taken. From the optimum percentage, fine aggregate is partially replaced by iron slag (0%,25%,35%,45%). For enhancing the workability of geopolymer mortar by using poly-carboxylic ether as superplasticizer. The optimum geopolymer mortar mix using industrial waste was concluded based on the compressive test to be studied with conventional.

Porous lead sulphide nanowalls structured film for ethanol detection in the short infrared regime

Porosity of semiconductor material has been used for various applications including gas sensing. However, the utilization of such materials for liquid sensing is still unexplored. Keeping this in mind, a highly porous structured film of lead sulphide (PbS) was engineered using a physical vapor deposition process. The fabricated PbS film was characterized for its shape and porosity using SEM, AFM, and Raman spectroscopy. Thus, the prepared PbS film was tested for various analytic aqueous media, such as ethanol, methanol, isopropanol, butanol, acetone, formaldehyde, and water for sensing. It was perceived that the prepared film was selectively responding to ethanol, while no such response was seen for the other analytic aqueous media and water. The prepared film showed a linear response for the detection of ethanol with the sensitivity of ∼0.002 transmission intensity (a.u.) per concentration of water (v/v%) at 1450 nm with a detection limit of 1.1%. Being operated in the short wavelength infrared range, this sensor can find applications in various fields, such as biofuel, medical, and organic chemistry. As compared to refractive index-based sensors which show nonmonotonic behavior with the concentration of water in ethanol, our sensor exhibits monotonic behavior over the whole range.

Recent Trends in Preparation and Applications of Biodegradable Polymer Composites

This review efficiently covers the research progress in the area of polymer bio composites in perspective of the modern-day renewable materials. In the last decade, attraction towards the bio-composite based systems has been the topic of interest due to their potential as a substitute of conventional materials produced in important manufacturing industries. Recently, preparation of biocompatible and biodegradable polymer composites is an important achievement as an alternative of petrochemical based renewable products. Successful production of eco-friendly bio-composite materials have been achieved with natural fibers viz jute, bamboo, hair, flex, wool, silk and many others instead of synthesized fibers like carbon, glass dispersed in synthesized resins viz poly vinyl alcohol, epoxy and etc. Biomaterials based on natural fibers dispersed in natural matrix like natural rubber or polyester have also been obtained with endless applications for the mankind. The utilization of such materials for the good well of mankind is attributed to their ease of disposal and being renewable. The last but not the least, the extraordinary mechanical properties of bio-composites make them superior to many other conventional materials. This review paper addresses the recent trends, mechanical and chemical properties, synthesis, and application of bio-composites in the recent years.

Modeling and characterization of the shape memory alloy–based morphing wing behavior using proposed rate-dependent Prandtl-Ishlinskii models

Unique features of shape memory alloys make them a proper actuation choice in various control systems. However, their nonlinear hysteresis behavior negatively affects wide utilization of such materials in structure actuation. In this study, the frequency effect on the hysteresis behavior of a shape memory alloy–actuated structure is experimentally investigated, and also two proposed versions of rate-dependent Prandtl-Ishlinskii (modified rate-dependent Prandtl-Ishlinskii and revised modified rate-dependent Prandtl-Ishlinskii) are presented, which are capable of characterizing this phenomenon. Experimental results show that increasing excitation frequency leads to bigger hysteresis loops. It is also proven that rate-dependency cannot be predicted by generalized Prandtl-Ishlinskii model. In addition, a comparison between the dead zone function-based rate-dependent Prandtl-Ishlinskii model as an only benchmark model and the proposed models have been done that proves the proposed models’ superiority. In addition, genetic algorithm is exploited to identify unknown parameters of all models. Trained models performance is also experimentally evaluated at different input frequencies. Comparison between simulation and experimental results indicates that the proposed models can reliably predict saturated, asymmetric, rate-dependent hysteresis behavior, and minor loops in shape memory alloy–embedded actuators.