Casting Procedure Research Articles

Insight into the Grain Refining Mechanism of Al–Ti–C and the Interfacial Properties between the Inoculants and Aluminum

The grain refinement mechanism of Al–Ti–C grain refiners used in the casting procedure of aluminum has been studied by first‐principles calculation. Considering the controversy over Al3Ti, TiC, or Al3Ti–TiC as nucleation sites, the adsorption behavior of possible nucleation surfaces for Al atoms, including adsorption energies and adsorption sites, as well as the interfacial properties of Al/Al3Ti/TiC are calculated and compared. In the results, it is shown that the Al3Ti(112) surface has a stronger adsorption capacity for Al than TiC. By using the edge‐to‐edge matching crystallographic model and the calculation of the adsorption energy, it is found that the monolayer Al3Ti(112) can be stabilized on the TiC(100) surface, and the combination of TiC and monolayer Al3Ti can significantly improve the adsorption capacity of Al. Interfacial electronic structure analysis shows stronger chemical bonding between Al and Ti at the Al/Al3Ti/TiC interface compared to Al/Al3Ti, which explains that the monolayer Al3Ti covering the TiC surface has the strongest adsorption capacity for Al atoms. Therefore, it is speculated that TiC with a monolayer of Al3Ti covering the surface will serve as a potential nucleation site during grain refinement, which will provide a theoretical reference for future research work.

Institutional Variability in Anesthesia Time for Mehta Casting in Early-Onset Scoliosis (EOS).

Mehta casting is a potentially curative intervention for early-onset scoliosis (EOS) that typically requires multiple anesthetics. The Food and Drug Administration (FDA) reported that >3 hours of anesthesia under the age of 3 years old may alter brain development; however, no standard exists for the duration of anesthesia during casting. The purpose of this study is to quantify the variability in anesthesia during Mehta casting. We hypothesize that significant institutional variability exists and may be attributed to modifiable factors. An EOS registry was used to identify patients who underwent at least one Mehta casting procedure. Anesthesia exposure was quantified, and site variability was assessed by patient characteristics, cast placement, procedure type, and equipment used. Our cohort consisted of 208 patients from 5 institutions (age 2.6±1.4y). There were 1097 Mehta casting procedures, with 5.4±3.6 castings per patient. Of these patients, 106 (51%) were female, with an average age of 2.11±1.29 years old at the time casting was initiated. Patient etiologies included 154 idiopathic (74.0%), 22 syndromic (10.6%), 18 congenital (8.7%), 11 neuromuscular (5.3%), and 3 unknown (1.4%). Anesthesia time was 69±31 minutes and varied significantly between sites (59±14 to 117±46min; P <0.001). Cumulative anesthesia time for patients under 3 years was 320±197 minutes with 120/161 (74.5%) patients exceeding 3 hours. Anesthesia time was lower after the FDA warning in 2016 compared with pre-2016 (71±30 vs. 66±32, P =0.008). Patients undergoing Mehta casting are at significant risk of exceeding 3 hours of anesthesia, which the FDA has stated may be harmful for children <3 years. Significant site variability indicates that standardization protocols should be developed to encourage best practices and minimize anesthetic times. Prognostic Level II.

BI-LAMINATED ORAL DISINTEGRATING FILM FOR SYMPTOMATIC TREATMENT OF VIRAL NASOPHARYNGITIS: FORMULATION, CHARACTERIZATION, TASTE MASKING, AND STABILITY STUDIES

Objective: Nasopharyngitis (NP) is one of the most common upper respiratory tract infections (URTIs) brought on by viral infections and requires symptomatic treatment. In this study, a new approach to delivering drugs was developed, which is a bi-laminated oral disintegrating film (ODF) containing dextromethorphan hydrobromide (DEX), phenylephrine hydrochloride (PE), and methylcobalamin (MeCbl) to support the symptomatic treatment of NP. Yet, the extreme bitterness of DEX and PE required a taste-masking technique before ODF formulation to enhance patient compliance. Methods: Various complexing agents were tried at different ratios to mask the bitter taste of the drug(s). DEX-PE ODFs were formulated using the solvent casting procedure. A 31.21 full factorial design was performed to characterize DEX-PE ODFs, where the effects of polymer grade and plasticizer type were evaluated on the disintegration time (DT) and the percentage of drugs released after 10 min (Q10). Results: Complexation with maltodextrin (MD) and ion exchange resin (Kyron T-314) could successfully mask the bitter taste at a ratio of 1:2:2 of drugs, MD, and Kyron T-314, respectively. The ODF optimized formula (F4) recorded the least DT (5±0.5 s) and highest Q10 (96.7±2.1%) and (97.4±1.9%) for DEX and PE, respectively. F4 was then combined with the second film layer containing MeCbl to develop the bi-laminated ODF (B1), which was later evaluated and subjected to stability studies. Conclusion: In conclusion, a taste-masked, bi-laminated ODF could be successfully developed for the symptomatic treatment of NP.

Influence of micro-addition of lanthanum on grain characteristics, mechanical properties, and corrosion behavior of CuAlNiMnLa shape memory alloy

The study investigated the grain size criteria, mechanical characteristics, and corrosion behavior of Cu-14Al-4.5Ni-0.7Mn shape memory alloy (SMA) with the micro-addition of 0.06 wt% Lanthanum (La). Using standard melting and casting procedures, the alloy compositions were melted at 1300 ℃ in an arc furnace with an argon atmosphere. The cast compositions without thermal treatment were machined and tested for physical properties including density and percentage porosity, corrosion behavior, and mechanical properties like hardness, ultimate tensile strength, yield strength, fracture strain, percentage elongation, specific strength, and fracture toughness. The average grain size, profile plot, and grain size distribution were all determined using ImageJ software. The microstructural observations revealed the presence of α-phase, β-phase, and intermetallic phases, including the coarse α+γ2 phase, which contributed to the improved characteristics. The inclusion of lanthanum resulted in a drop in the average grain size of the parent alloy from 9.25 μm to 6.08 μm, indicating a clear correlation between property improvement and microstructure refinement. The composition's tensile strength and yield strength increased with the La micro-addition by 22.14% and 20.31% respectively while the hardness value increased by 17.3%. The fracture strain of the modified composition increased by 20% compared to the unmodified composition while the percentage elongation increased by 7.7% and a 22.5% increase in fracture toughness was achieved. The modified CuAlNiMn SMA also showed a significant improvement in corrosion resistance to NaCl solutions which was so evident at 144 hours of the study for 0.5 M of NaCl solution and at 96 hours for 1.0 M of NaCl solution. The results showed that CuAlNiMn SMA with micro-addition of La had better physical, corrosion, and mechanical characteristics than unmodified CuAlNiMn alloys

Sisal fiber reinforced mortar for 3D printing applications in construction

The use short fibers in mortars can address some issues for 3D printing (3DP) technology, providing reinforcing and improving material sustainability. Among fibers, Sisal fiber (SF) is a good option for mortar reinforcement due to its natural origin, irregular cross-section and high flexibility. The aim of this study was to assess fresh and hardened properties of sisal fibers on 3D printable bio-based mortars for architectural applications. A 3D printable reference mortar with a 0-0.6 sand and a water to cement ratio of 0.45 was designed. The reference mortar was reinforced with 0.5, 1 and 1.5% volumetric fraction (VF) of 13 mm length SF and with 1% VF of a shorter SF of 6.5 mm length. An experimental evaluation of 3DP mortars comprising several rheological parameters at fresh state and physical and mechanical properties in hardened state was carried out to assess mortars’ extrudability, printability and hardened performance. Printability was also evaluated by trials using a manual extruder and a robotic 3D printer. It was found that SF reduced mortar consistency initially and over time, modifying effective thixotropy. On the other hand, the length and amount of SF and the casting procedure showed differences on the physical and mechanical properties. Mortars with small SF amounts showed good printability while higher amounts were prone to clog the 3DP pumping system.

DOE-based multi-criteria optimization of starch/gly/CMC films’ composition and preparation procedure by casting deposition

Bioplastic materials represent a hot topic in the recent literature, with a particular focus on starch-based materials; despite the huge composite films proposed, bioplastics' weak points are still limiting their large-scale applications. In this work, we propose a DOE-based multi-criteria optimization of starch/gly/CMC films targeted to improve both film composition and lab-scale preparation. Film composition, starch source and CMC type are studied by mixture-process combined design to model and improve films’ tensile properties and solubility in water while the Plackett-Burman design is applied to screen between several casting procedure variants in search for an easy, reliable and reproducible lab-scale methodology. The chemometric approach allows us to identify the optimal composition to achieve both film flexibility and low solubility and to identify a successful and reproducible lab-scale preparation method.

Optical and Color Investigation of the Effect of Laser Radiation on Polyaniline/Polyvinyl Pyrrolidone/Zinc Sulfide Nanocomposite Films

A nanocomposite (NC) of polyaniline (Pani), polyvinyl pyrrolidone (PVP) and zinc sulfide (ZnS) nanoparticles (NP) was prepared using chemical coprecipitation and ex-situ casting procedures. ZnS NP were synthesized using the chemical coprecipitation technique in atmospheric air. The x-ray diffraction (XRD) scans indicated that the synthesized ZnS had a nanonature and fit the cubic zinc blended structure. We used an infrared pulsed laser to irradiate the Pani/PVP/ZnS NC samples with fluences ranging from 3 to18 J/cm2. The induced changes in the NC were investigated using the UV spectroscopy and International Commission on Illumination (CIE) color difference methodology. When the laser fluence increased up to 18 J/cm2 both the direct and indirect optical bandgaps (Eg) decreased. Additionally, we used the optical dielectric loss (ε”) to detect the type of microelectronic transition for the NC samples. The Eg of the exposed NC samples and the pristine samples exhibited indirect allowed transitions. The laser effects on the absorbance, extinction coefficient, transmission, refractive index, dielectric parameters and optical conductivity of the NC were studied. Lastly, the color differences between the pristine and exposed samples were determined. The pristine Pani/PVP/ZnS showed a significant color difference with the laser irradiated samples. The changes of the studied optical parameters with the laser fluence indicated that the laser radiation represents a convenient tool that would allow the application of Pani/PVP/ZnS NC in optoelectronic devices.

MoO3 nanoplates reinforced the structural, electrical, mechanical, and antibacterial characteristics of polyvinyl pyrrolidone/sodium alginate polymer blend for optoelectronics and biological applications

Organic/Inorganic nanostructures enable the development of new functional materials for optoelectronics and biological applications. In this work, nanocomposite films of polyvinyl pyrrolidone (PVP) and sodium alginate (NaAlg) blend matrix (30/70 wt%) filled with molybdenum trioxide (MoO3) nanoplates were prepared using solution casting procedure. The effect of MoO3 nanoplates on structural, optical, electrical and antibacterial characteristics of pure PVP/NaAlg blend was investigated. The sizes of MoO3 nanoplates had dimensions between 90 and 420 nm with orthorhombic phase as indicated by the TEM and XRD techniques. Also, the XRD patterns of filled films suggested that the presence of crystalline phases of MoO3 within PVP/NaAlg matrix. FTIR analysis revealed the primary vibrational peaks of PVP and NaAlg, whose strength altered randomly after filling. The UV absorption increased gradually and shifted to the higher wavelength side. The alternating current (AC) conductivity and dielectric parameters were improved with increasing MoO3 concentration. The antibacterial activity against Staphylococcus aureus and Escherichia coli increased with increase of MoO3 nanoplates concentration. The filled PVP/NaAlg-MoO3 samples displayed considerable enhancements in the values of Young's modulus (Y), tensile stress (σt) and elongation at break (εB). The obtained results imply that these nanocomposite films can be potentially used in optoelectronics and biological applications.

Fabrication and characterization of ADC-12 hybrid composites utilizing lemon grass ash and boron nitride through stir-squeeze casting method

In recent years, there has been increased interest in hybridizing metal matrix composites using agro-based-waste materials as sustainable choices. Despite the poor tribo-mechanical properties of conventional reinforcement materials, there is immense potential for using alternate reinforcing elements to enhance the mechanical features of matrix composite. In addition, conventional casting procedures present several challenges, including high costs and a lack of adequate mechanical qualities in the finished product. To combat these issues, the authors herein produce the well-known aluminium matrix composite (AMC), ADC 12 alloy, using waste lemon grass (LG) ash at a fixed rate (6 wt%) and hexagonal Boron Nitride (hBN) at variable proportions (0, 1.5, 3, 4.5, and 6 wt%) as reinforcing element against traditional reinforcement particles to enhance the tribo-mechanical properties of casted hybrid AMC. In addition, the Stir-Squeeze Casting method produces the hybrid AMC, dramatically decreasing production costs and enhancing final product qualities. The hybrid AMC formed by Stir-Squeeze Casting is examined for its mechanical, corrosion, and tribological characteristics, with the findings indicating that the addition of LG and hBN improved the mechanical, corrosion, and tribological properties of the ADC-LG-hBN composites, with 6 wt% LG and 4.5 wt% hBN reinforcements producing the optimal result. The experimental density of ADC-LG- hBN composites was reduced by 8% when compared to the ADC 12 alloy, while the composites’ tensile, hardness and compressive strength were increased by 118.9%, 36.7%, and 33.6%, respectively. Similarly, the developed composite showed an improved corrosion resistance of 43.8% for 24 h, and the wear rate decreased by 90.4%.

Reinforcement of linear/nonlinear optical and dielectric characteristics of PVC/PEG blend based on CeO2/TBAI filler

Blended polymer nanocomposites with novel enhanced properties are gaining in popularity around the world, prompting an increase in their production. In this study, cerium dioxide (CeO2) nanoparticles were prepared via the sol–gel method and PVC/PEG/CeO2/x wt % tetrabutylammonium iodide (TBAI) blends were prepared via the casting procedure. The influence of CeO2/TBAI doping on the structural, optical, and dielectric features of formed blends was analyzed. The structural characteristics were studied using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and scanning electron microscope (SEM) techniques. XRD shows a creation of nano CeO2 with a cubic structure and semicrystalline phase of undoped and doped PVC/PEG/CeO2/TBAI blends. SEM and EDS techniques confirm the presence of the filler in the blend matrix. The optical characteristics appeared in the modification in optical band gap from (4.27, 5.05) to (3.01, 3.84) eV for a direct optical band gap and from (4.06, 4.58) to (2.51, 3.51) eV for an indirect optical band gap. In the same way, the values of linear and nonlinear parameters of PVC/PEG blends are altered with the doping of nano CeO2/TBAI. Doped blends have higher dielectric permittivity and ac conductivity than PVC/PEG blend. The effect of doping on the emitted colors from different blends was examined under different excitation wavelengths. According to the experimental results, these films show promise for good absorbance for different types of UV spectra, and energy storage devices.

Formulation Development and Cevaluation of Mucoadhesive Patch for Diabetes Using Plant Based Polysaccharide

Abstract: Using plant-based polysaccharides, this study created a mucoadhesive patch for diabetes with the goal of delivering regulated medication release and improved therapeutic efficacy through sustained contact with the buccal mucosa. The patches' physicochemical characteristics, drug release kinetics, and mucoadhesive strength were examined after they had been made using the solvent casting procedure. . The created patch had exceptional mechanical, flexible, and physical qualities, as well as prolonged drug release and minimized burst release. Through in vitro cytotoxicity tests, the patch's biocompatibility was verified, demonstrating its suitability for buccal administration.the buccal region offcers and attractive route of administration for systemic drug delivery. The patches were prepared by solvent casting method the design of patches were evaluated for thickness, uniformity ,folding ,endurance ,weight uniformity ,swelling behavior,determination of mucoadhesive time. . To confirm the effectiveness and safety of this unique medication delivery method, additional in vivo research and clinical trials are required. If successful, these studies could pave the way for more individualized and efficient diabetic treatment options.

Sustainable approach to oil recovery from oil spills through superhydrophobic jute fabric

Ecosystems suffer from increased oil exploitation and frequent oil spills, which calls for effective, environment-friendly, and economically viable solutions. To address this, abandoned gunny sacks as the concerned jute fabric were superhydrophobically (water contact angle ∼159°) modified, incorporating titanium dioxide (TiO2) nanoparticles and hexadecyltrimethoxysilane (HDTMS), rendering a facile drop casting procedure. The modified superhydrophobic-superoleophilic jute fabric has been identified as a high-performance filter with superior reusability that can separate oil-water mixtures in challenging environmental conditions (including potent acidic, alkaline, highly saline, aqueous, frigid, and blistering water environments) while maintaining high separation efficiency. In continuation, static conditions indulging a batch and continuous oil separation performance and dynamic conditions stimulating turbulence in the oil-water mixture were proficiently carried out, mimicking real-world circumstances. As a result, the modified jute fabric has the advantages of high separation efficiency, stable recyclable properties, and outstanding durability, highlighting its enormous potential for use in practical applications.

Fabrication of flat stainless steel substrates with improved oxidation behavior for metal-supported solid oxide cells using aqueous tape casting

An aqueous tape casting procedure was developed and optimized to fabricate thick, flat tapes for use as porous stainless-steel substrates for metal-supported solid oxide cells (MS-SOCs). Curling tape is one of the main challenges when using aqueous based slurry formation. This work demonstrated that the sedimentation problem can be solved by increasing solid loading rather than adding excessive binder to raise viscosity. The effect of various casting surfaces on tape curling was also investigated. Materials that allow easy tape release resulted in flatter tapes once the water was evaporated. In addition, substrate oxidation resistance at high temperature was evaluated with respect to starting powder size, sintering extent, and pore former types. High sintering extent that removes or encloses the porosity between steel particles while retaining porosity left by pore formers can effectively prevent breakaway oxidation due to local chromium depletion. Carbon residue in the steel substrates from the slurry organic content can be decreased when formulating the slurry to prevent Cr-rich phase formation in the steel, which severely compromises the substrate oxidation resistance and ductility. By dwelling the substrate in high purity hydrogen, the sensitization can be reversed, but more detailed investigation of the reaction dynamics is needed. By combining the strategies described, this work produced crack-free, flat, 400–500 μm thick stainless steel substrates with 28.7 vol% porosity and improved oxidation resistance compared to previous substrates fabricated by dry pressing of fine powders.

Chloride-induced 3D non-uniform corrosion of steel in reinforced concrete considering mesoscale heterogeneities and early-age cracks

Considering that reinforced concrete structures typically work with cracks, this work aims to investigate the chloride-induced non-uniform corrosion of steel by proposing a five-phase cracked reinforced concrete model at mesoscale, including realistic aggregate, matrix, steel, early-age crack, and damage zone. A physically-based 3D mesoscale modeling approach is developed to accommodate all the phases by integrating gravity-driven compaction and vibration as in real casting procedures. This modeling approach is further developed to capture coupled mass transfer and electrochemical corrosion of steel, enabling simulations of non-uniform corrosion along both the circumferential and longitudinal directions of steel. The considerable variation in corrosion morphology due to aggregate distribution demonstrates the necessity of using 3D mesoscale models to predict steel corrosion. Early-age cracks accelerate the diffusion of corrosive agents, intensifying the corrosion of steel. Increasing the crack width, depth, and length all contribute to a higher dissolution thickness of the steel. With the same crack size, longitudinal cracks result in a larger average dissolution thickness of the steel. In addition, the maximum dissolution thickness of the steel is highly correlated with the degree of pitting corrosion, and in most instances, transverse cracks lead to a higher degree of pitting, causing a greater maximum dissolution thickness.

To Cut or to Cast? An Evaluation of Demographics &amp; Mortality in Operative, Conservative, and Failed- Conservative Management of Charcot Neuroarthropathy

Category: Midfoot/Forefoot; Diabetes Introduction/Purpose: Charcot neuroarthropathy (CN) is a chronic, destructive disease linked with diabetic neuropathy that affects the bone structure, joints, and soft tissues of the foot. Treatment can vary from a conservative shoe modification to a below-the-knee amputation (BKA). With no evidence based guidelines for CN management, treatment regimens are physician specific and dependent on stage of CN, comorbidities, and ulceration status. Further, no previous literature has compared the mortality rates of patients that are treated with casting versus common surgical procedures for CN. Here, we provide demographic and all-cause mortality data for patients who underwent casting, arthrodesis, exostectomy, and amputation, to evaluate the outcomes and characterize the populations treated for Charcot neuroarthropathy of the foot. Methods: Institutional review board approval was obtained. A database of all patients from 1/1/2000 to 1/31/2022 with CPT and ICD codes indicating a diagnosis of Charcot neuroarthropathy who underwent exostectomy, arthrodesis, minor amputation, major amputation, and/or casting was created from the electronic medical record. Demographic and mortality data was collected, including date-of-birth, sex, race, and all-cause mortality. Procedure data was collected, which included date, code, and description. Major amputations include transtibial and trans-metatarsal, whereas minor amputations include toe and metatarsal. In the casting group, patients were separated into two groups: casting as the sole intervention and failed casting that ultimately went on to have surgery. Patients who had postoperative casting or multiple instances of casting and surgery were excluded. Descriptive statistics were conducted and single-factor ANOVA and Chi squared tests were used for analysis. Results: A total of 2,130 patients were identified; 546 had arthrodesis, 488 had exostectomy, 677 had minor amputations, 332 had major amputations, 64 had casting only, and 23 failed casting. Of the 23 patients who failed casting and went on to have surgery, 11 had arthrodesis, 5 had exostectomy, 4 had minor amputation, and 3 had major amputation. The average overall was 57.7 ± 13.9. Mortality rates were 10.3%, 11.3%, 34.0%, 32.2%, 7.8%, 17.4% in the arthrodesis, exostectomy, minor amputation, major amputation, casting only, and failed casting groups, respectively (Figures 1A and 1B). Of those that failed casting and then had surgery, arthrodesis was the most common procedure. Conclusion: Treatment options for patients with CN range from simple casting to invasive amputation. Overall, patients who underwent casting as their sole intervention had a significantly lower all-cause mortality (7.8%) compared to those who had amputation (34% for minor amputations and 32.2% for major amputations). There was no significant difference in all-cause mortality between casting only and failed casting groups. These findings demonstrate a significant disparity in outcomes between conservative and operative management for CN. Understanding the mortality of the various treatment options for CN can help optimize standards of care to improve patient outcomes.

Structural, Optical and Electrical Studies on Poly(methyl methacrylate) Polymer Loaded with CuCo2O4/CuS Mixtures

Polymethyl methacrylate (PMMA)/(1-x)CuCo2O4/xCuS (x = 0, 0.1, 0.25, 0.5) nanocomposites polymers were formed using hydrothermal, solid state and solvent casting procedures. The structure of the filler and polymer nano-composite samples were examined using an X-ray diffraction technique. The impacts of the (1-x)CuCo2O4/xCuS mixture on the diffuse absorption, transmittance, reflectance, extinction coefficient, refractive index, optical dielectric constant, energy loss functions and optical conductivity were investigated. The absorbance of PMMA/(1-x)CuCo2O4/xCuS changed depending on the percentage of CuS in the nanocomposite. The optical band gaps (Eg ) for PMMA were 4.52 and 4.46 eV, directly and indirectly, respectively. The sample with x = 0.25 produced the lowest direct/indirect Eg values, 4.34 and 3.79 eV. The fluorescence spectra of the undoped and doped PMMA polymers were explored. Depending on the filler composition in the PMMA/(1-x)CuCo2O4/xCuS samples, the emitted colors could be modulated. The effects of the (1-x)CuCo2O4/xCuS mixture as a function of the dielectric constant, dielectric loss, ac conductivity and electric modulus of the host polymer were examined.

Effect of Ag/CuS nanoparticles loading to enhance linear/nonlinear spectroscopic and electrical characteristics of PVP/PVA blends for flexible optoelectronics

AbstractDue to the novel physicochemical properties of polymeric nanocomposites (PNCs), a remarkable role of PNCs has been accomplished in plenty of flexible optoelectronic applications. Solution cast procedure has been performed to prepare different contents (0.1, 0.5, 1.0, 5.0, and 10 wt%) of Ag1.6Cu0.2S (ACS) incorporated in PVP/PVA blend. Fourier transforms infrared and scanning electron microscope measurements were carried out to investigate the influence of ACS on PVP/PVA structure and morphology. UV–visible spectrophotometry technique was applied to examine PVP/PVA optical properties modifications. Spectroscopic analysis reveals that direct/indirect optical bandgap of PVP/PVA host shrinks from 5.21/4.95 eV (PVP/PVA0) to 4.87/4.54 eV (PVP/PVA10). Moreover, obvious enrichments in the whole linear/nonlinear optical parameters are achieved by ACS doping. For example, refractive index and dielectric constants of PVP/PVA are increased from 1.69 and 2.87 to 1.91 and 3.63 (PVP/PVA10). While two orders of magnetite enhancement in nonlinear third‐order susceptibility are achieved via 10% ACS doping. The electrical performance of ACS PNCs has been explored, which discloses remarkable enrichments in PVP/PVA DC‐electrical conductivity () and activation energy. The obtained structural, spectroscopic and electrical investigations prove that ACS PNCs could play an efficient role in plenty of optoelectronic applications.Highlights Solution casting was used to prepare PVP/PVA loaded with Ag/CuS (ACS) NPs. FT‐IR analysis reveals successful incorporation of ACS in PVP/PVA structure. Enrichments in linear/nonlinear optical parameters are achieved by ACS doping. Electrical performance of ACS PNCs has greatly been enhanced. ACS PNCs could play an efficient role in plenty of optoelectronic applications.

MWCNTs Decorated with TiO2 as Highly Performing Filler in the Preparation of Nanocomposite Membranes for Scalable Photocatalytic Degradation of Bisphenol A in Water.

Bisphenol A (BPA), an endocrine-disrupting compound with estrogenic behavior, is of great concern within the scientific community due to its high production levels and increasing concentration in various surface aquifers. While several materials exhibit excellent capacity for the photocatalytic degradation of BPA, their powdered nature and poor chemical stability render them unsuitable for practical application in large-scale water decontamination. In this study, a new class of nanocomposite membranes based on sulfonated polyethersulfone (sPES) and multiwalled carbon nanotubes decorated with TiO2 nanoparticles (MWCNTs-TiO2) were investigated as efficient and scalable photocatalysts for the photodegradation of BPA in aqueous solutions. The MWCNTs-TiO2 hybrid material was prepared through a facile and inexpensive hydrothermal method and extensively characterized by XRD, Raman, FTIR, BET, and TGA. Meanwhile, nanocomposite membranes at different filler loadings were prepared by a simple casting procedure. Swelling tests and PFG NMR analyses provided insights into the impact of filler introduction on membrane hydrophilicity and water molecular dynamics, whereas the effectiveness of the various photocatalysts in BPA removal was monitored using HPLC. Among the different MWCNTs-TiO2 content nanocomposites, the one at 10 wt% loading (sP-MT10) showed the best photoactivity. Under UV irradiation at 254 nm and 365 nm for 240 min, photocatalytic oxidation of 5 mg/L bisphenol A by sP-MT10 resulted in 91% and 82% degradation, respectively. Both the effect of BPA concentration and the membrane regenerability were evaluated, revealing that the sP-MT10 maintained its maximum BPA removal capability over more than 10 cycles. Our findings indicate that sP-MT nanocomposite membranes are versatile, scalable, efficient, and highly reusable photocatalysts for the degradation of BPA, as well as potentially for other endocrine disruptors.

Effective reinforcement of plasticized starch by the incorporation of graphene, graphene oxide and reduced graphene oxide

Plasticized starch (PLS) nanocomposite films using glycerol and reinforced with graphene (G) and graphene oxide (GO) were prepared by solvent casting procedure. On one hand, the influence of adding different G contents into the PLS matrix was analyzed. In order to improve the stability of G nanoflakes in water, Salvia extracts were added as surfactants. The resulting nanocomposites presented improved mechanical properties. A maximum increase of 287 % in Young's modulus and 57 % in tensile strength was achieved for nanocomposites with 5 wt% of G. However, it seemed that Salvia acted as co-plasticizer for the PLS. Moreover, the addition of the highest G content led to an improvement of the electrical conductivity close to 5 × 10−6 S/m compared to the matrix.On the other hand, GO was also incorporated as nanofiller to prepare nanocomposites. Thus, the effect of increasing the GO content in the final behavior of the PLS nanocomposites was evaluated. The characterization of GO containing PLS nanocomposites showed that strong starch/GO interactions and a good dispersion of the nanofiller were achieved. Moreover, the acidic treatment applied for the reduction of the GO was found to be effective, since the electrical conductivity was 150 times bigger than its G containing counterpart.

AN EXPERIMENTAL RESEARCH CONTRIBUTION TO THE USE OF CARBON NANOTUBES IN CEMENT COMPOSITES

Indeed, cement is the second most widely used material after water, with annual global cement production exceeding 4 billion tons in each of the last ten years. Cementitious composites are favored in construction because of their high compressive strength, low cost of preparation, simple manufacturing method, and ease of usage. However, these composites have several drawbacks, including a low tensile capacity, poor deformation performance, and a high cracking tendency, all of which impact the long-term durability of constructions. Carbon nanotubes can reinforce at the nanoscale, which was not possible before. Experimental work was conducted, and specimens of cement pastes and mortars were cast toward testing the carbon nanotubes’ dispersion within the matrix. Carbon nanotubes are known for being very cohesive in their raw form and difficult to disperse into the water. Using ultrasonic energy (bath sonication) along with incorporating a polycarboxylate high-range water-reducing agent to disperse the multiwalled carbon nanotubes helped to achieve about an 18% gain in compressive strength for cement pastes compared to plain cement pastes. This observed gain in strength was evidence of reinforcement. Several aspects explain the restricted work of carbon nanotubes on the industrial scale, including the high price of carbon nanotubes, the absence of standards and confirmations, and the complexity of dispersions, mixing, transporting, casting, and sufficient curing procedures. However, these practical difficulties could be partially resolved by improving the dispersion method or using pre-dispersed carbon nanotubes, which would be encouraging and useful for further exploration at the laboratory scale and the industry floor.