Filler Material Research Articles

Comprehensive comparison of integrated fixed-film activated sludge (IFAS) and AAO activated sludge methods: Influence of different operational parameters

Due to limited land availability in municipal wastewater treatment plants, integrated fixed-film activated sludge (IFAS) technology offers significant advantages in improving nitrogen removal performance and treatment capacity. In this study, two systems, IFAS and Anaerobic-Anoxic-Oxic Activated sludge process (AAO), were compared by adjusting parameters such as hydraulic retention time (HRT), nitrifying solution recycle ratio, sludge recycle ratio, and dissolved oxygen (DO). The objective was to investigate pollutant removal capacity and differences in microbial community composition between the two systems. The study showed that, at an HRT of 12 h, the IFAS system exhibited an average increase of 5.76%, 8.85%, and 12.79% in COD, NH4+-N, and TN removal efficiency respectively, compared to the AAO system at an HRT of 16 h. The TP concentration in the IFAS system reached 0.82 mg/L without the use of additives. The IFAS system demonstrated superior effluent results under lower operating conditions of HRT, nitrification solution recycle ratio, and DO. The 16S rDNA analysis revealed higher abundance of denitrification-related associated flora, including Proteobacteria, Bacteroidetes, and Planctomycetota, in the IFAS system compared to the AAO system. Similarities were observed between microorganisms attached to the media and activated sludge in the anaerobic, anoxic, and oxic tanks. q-PCR analysis indicated that the incorporation of filler material in the IFAS system resulted in similar abundance of nitrifying bacteria genes on the biofilm as in the oxic tank. Additionally, denitrifying genes showed higher levels due to aeration scouring and the presence of alternating aerobic-anaerobic environments on the biofilm surface, enhancing nitrogen removal efficiency.

Physico-electrical properties of starch-based bioplastic enhanced with acid-treated cellulose and graphene oxide fillers

Biopolymer composites represent an emerging alternative to petroleum-derived polymers for applications in electronic devices. Cellulose from Luffa cylindrical was treated with acid, and graphene oxide was produced from waste battery rod graphite. The two products were characterized using FTIR, SEM, TGA and XRD. After that, starch-based bioplastic films with varying amounts of acid-treated cellulose (ALC-cellulose) and graphene oxide (GO) as fillers were prepared, and the physical and electrical properties were determined. XRD data revealed a crystallinity of 62% for the ALC-cellulose and 52% for the cellulose precursor. GO had a d-spacing of 0.76 nm compared to 0.29 nm for battery-sourced graphite. TEM micrograph analyses revealed an average fibre diameter of 44.7 nm for acid-treated cellulose and 99.7 nm for cellulose. The density, thickness, opacity, and tensile strength of the bioplastic films increased from 1.31 to 1.44 g/cm3, 0.21–0.48 mm, 14.78–38.64, and 0.98–1.42 MPa, respectively, while the moisture content, swelling ability, and porosity reduced, with an increase in percentage composition of the filler materials. The dielectric constant and conductivity increased from 50.3 to 6965.2 and 0.0036–0.0147 S/m with an increase in percentage composition of the filler materials except for Filmcr4, which showed a drop in dielectric constant (3033.73) and conductivity (0.0074 S/m). Overall, this study has demonstrated that bioplastic filler materials can be sourced from waste materials and that these fillers improved the starch-based bioplastic film's physical and electrical properties.

Production and characterization of sustainable biocompatible PLA/walnut shell composite materials

Various treatments, such as alkaline and silane treatments, are commonly applied to natural fillers before production to enhance their quality, thermal stability, and water absorption capacity and improve the fiber–matrix interface properties. However, these processes are not environmentally friendly and may escalate the production cost of composites due to the need for additional processing steps in mass production. This study delves into the impact of untreated walnut shell (WS) filler material, employed in varying ratios (ranging from 10 to 40%) as a filler, on the mechanical, thermal, morphological, and physical properties of environmentally friendly polylactic acid (PLA) matrix composites. The experimental results highlight a significant decrease in tensile modulus by 28%, tensile strength ranging from 32 to 65%, a decrease in flexural modulus by 22%, and flexural strength ranging from 24 to 58% with varying WS filler ratios. Time-dependent water absorption and increased density were observed. FT-IR analysis indicates structural similarities, while DSC results show minimal effects on glass transition temperature and crystallinity. TGA results reveal reduced thermal stability with increasing WS content. SEM microstructure imaging demonstrates homogeneous WS particle distribution, but higher WS content leads to increased brittleness and diminished resistance properties. In conclusion, this study underscores the importance of balancing sustainability through WS filler ratios while preserving mechanical performance.

Isocyanate‐chitin modified microspheres for chiral drug separation in high performance liquid chromatography

AbstractIn this work, a two‐step activated swelling technique was effectively employed to successfully synthesize monodisperse porous poly(styrene‐divinylbenzene) (PS‐DVB) particles. Diazoresin (DR) transform an ionic bond into a covalent bond by photoreaction. Under ultraviolet irradiation, DR was used to covalently attach dichlorophenyl isocyanate to sulfonated PS‐DVB microspheres. The novel photo‐crosslinking reaction effectively overcomes the toxicity issues associated with conventional coupling agents and enables green production of chromatographic fillers. Modified PS‐DVB particles were indeed commonly used as filler material for the separation of chiral compounds by high performance liquid chromatography (HPLC). The porous modified microspheres designed effectively separate benzoone, DL‐mandelic acid, 2‐phenylcyclohexanone, ibuprofen, 2‐hydroxyl flavone, DL‐cysteine, chloraniline maleate, hesperidin, and other chiral compounds by 100 mm column. It is noteworthy that the isocyanate‐chitin modified microspheres are effective in separating chiral drugs (1000 μg/mL) within 5 min. Compared with ordinary microspheres, porous isocyanate‐chitin modified microspheres showed better separation efficiency under the same conditions. The enhancement is attributed to the increase in their specific surface area. Consequently, they are a better choice of chromatographic packing matrix.

Suppression of Ag dewetting in submicron Cu@Ag particles in paste for improving sinter bondability through surface modification

Operating temperature of a wide-bandgap semiconductor-based power device can reach 300 °C, which requires a next-generation die-attach sinter material. Ag-coated Cu (Cu@Ag) particles have been considered as a low-cost filler material in pastes for sinter bonding, replacing pure Ag particles. However, there are two main problems: out-diffusion of core Cu and Ag dewetting. Although the Ag shell is sufficiently thick, Ag dewetting induces accelerated out-diffusion of the core Cu and the resultant Cu oxidation through the formation of thin Ag coating parts. Accordingly, a surface-modification method using stearic acid was developed to suppress Ag dewetting and improve the sinterability of Cu@Ag particles. Sinter-bonding characteristics were examined using pastes containing surface-modified submicron Cu@Ag particles. Sinter bonding was conducted at 250 °C under 10 MPa for 1–10 min with N2 blowing using eight types of initial and surface-modified submicron Cu@Ag particles with Ag contents of 10, 20, 30, and 40 wt% (A10, A20, A30, and A40). The shear strength of the bondline containing surface-modified A10 exhibited 17.56 MPa when bonded for 3 min, compared with 11.67 MPa of the initial A10. After a bonding time of 10 min, the shear strength increased to 20.41 MPa. Surface-modified A10 (low Ag content), with the highest efficiency in Ag dewetting suppression, exhibited sinter-bonding characteristics similar to those of Cu@Ag particles with higher Ag contents without surface treatment. Surface-modified A20 provided a sufficient strength of 20.83 MPa after 3 min of bonding.

Low operating pressure hydrophilic MOF-801/Biopolymer interfacial membrane for defluoridation and Co-Organic pollutant remediation

In the context of the energy-water nexus, where the demand for clean water intersects with the imperative for energy-efficient water treatment solutions, this research is dedicated to achieving low-pressure-driven membrane solution. Herein, study uses new class of active MOF-801 fillers materials that are in to stable biopolymers matrix to address the pervasive issue of fluoride contamination in drinking water. By harnessing the synergistic potentials of biogenic chitosan-sodium alginate (CS:SA) multilayers combined with MOF-801 fillers on the polyether sulfone (PES) porous support matrix. This study not only achieves significant improvements in fluoride removal but also enhances with exceptional resistance to fouling. Target specific designed membranes also exhibit versatility in effectively removing various emerging pollutants including fouling agents (BSA, TA, HA) and organic dyes (CR, MO, MB, CV), with a flux of > 40 L·m−2·h−1. The optimized membrane showed exceptional stability under different pH condition showed great separation performance and regeneration capabilities, as well as its effectiveness in defluoridation of groundwater feed. Large scale testing of defluoridation abilities tested for ∼5000 L of feed with a fluoride ion distribution coefficient (Kd) of 45621 mL/g at 4 bars of pressure. Therefore, the optimized membrane stands as an ideal candidate for applications within the energy-water nexus, where sustainability and resource efficiency are of paramount importance.

Structural integrity and corrosion behavior assessment of the dissimilar gas tungsten arc welded joint of sDSS 2507/ IN625 superalloy

This study investigates the effect of filler materials on the structural integrity of dissimilar welded joints (sDSS 2507/IN625) employed in marine subsea manifold applications. Multi-pass gas tungsten arc welding (GTAW) using ER2594 and ERNiCrMo-3 fillers investigates microstructure evolution, solidification mechanisms, mechanical characteristics, residual stresses, and corrosion behavior. Optical and scanning electron microscopy revealed an unmixed zone (peninsula/island-shaped) at the weld interface and weld zone (WZ) in both filler weldments. Segregation of Mo, Nb, and Ni was observed in the interdendritic region of ERNiCrMo-3 filler WZ, whereas the skeletal ferrite matrix of ER2594 filler WZ revealed the existence of the Laves phase (Fe2Nb form). Electron beam scattered diffraction (EBSD) investigation showed austenitic solidification for ERNiCrMo-3 and fully ferritic solidification for ER2594 with distinct dendrite formations. Inhomogeneity has been observed in microhardness maps, with ER2594 and ERNiCrMo-3 WZ averaging 310 ± 7 Hv0.5 and 270 ± 10 Hv0.5, respectively. ERNiCrMo-3 (165 ± 5 J and 180 ± 3 J) and ER2594 (100 ± 3 J and 110 ± 6 J) fillers exhibited distinct effects on toughness in the weld cap and root due to laves phase precipitation. Additionally, ER2594 (750 ± 6 MPa) and ERNiCrMo-3 (790 ± 7 MPa) fillers exhibited lower tensile strength than base metals. The structural integrity of WZ can be better understood by residual stress analysis, which showed compressive cap pass and tensile root pass residual stresses for both fillers. In a 3.5 wt% NaCl solution, both fillers exhibited outstanding corrosion resistance in marine conditions. These findings improve subsea manifold structure integrity and performance in corrosive marine environments.

The Effect of Chitosan Incorporation on Physico-Mechanical and Biological Characteristics of a Calcium Silicate Filling Material.

A tricalcium silicate-based cement, Biodentine™, has displayed antibiofilm activity when mixed with chitosan powder. This study aimed to assess the effect of chitosan incorporation on the physico-mechanical and biological properties of Biodentine™. In this study, medium molecular weight chitosan powder was incorporated into Biodentine™ in varying proportions (2.5 wt%, 5 wt%, 10 wt%, and 20 wt%). The setting time was determined using a Vicat apparatus, solubility was assessed by calculating weight variation after water immersion, radiopacity was evaluated and expressed in millimeters of aluminum, the compressive strength was evaluated using an Instron testing machine, and the microhardness was measured with a Vickers microhardness tester. In addition, surface topography of specimens was analyzed using scanning electron microscopy, and the effect of chitosan on the viability of human embryonic kidney (HEK 293) cells was measured by a colorimetric MTT assay. Incorporation of 2.5 wt% and 5 wt% chitosan powder delivered an advantage by speeding up the setting time of Biodentine material. However, the incorporation of chitosan compromised all other material properties and the crystalline structure in a dose-dependent manner. The chitosan-modified material also showed significant decreases in the proliferation of the HEK 293 cells, signifying decreased biocompatibility. Chitosan incorporation into calcium silicate materials adversely affects the physical and biological properties of the material. Despite the increased antimicrobial activity of the modified material, the diminution in these properties is likely to reduce its clinical value.

Low carbon stabilization of Hong Kong marine deposits by sewage sludge ash for land reclamation

Fill material is highly demanded in land reclamation. In Hong Kong, around 3000 tonnes of dredged marine deposits are produced per day which can be used as fill material after stabilization. Traditionally, cement is used to stabilize marine deposits, however, cement production results in high energy consumption and carbon emissions. Therefore, this study aims to recycle dredged marine deposits to serve as fill material and replace cement with sewage sludge ash (SSA) to reduce the carbon footprint. The samples have a constant binder content of 20%, in which cement is partially replaced by SSA with a replacement ratio (R) varying from 0 to 60%. Unconfined compression tests were performed to study their mechanical behaviors. Although larger R is preferred to replace more cement, the unconfined compressive strength (qu) decreases exponentially with R and reduces by around 50% when R is 60%. qu also decreases with water to binder ratio (W/B), while increasing with curing time. The increase of strength can be attributed to more hydration products, which could bond the soil particles and fill the pores. This is supported by the X-ray diffraction (XRD) results and scanning electron microscopy (SEM) images. Based on the results, a modified basicity coefficient is proposed and validated for the strength prediction of ash-stabilized soil considering chemical compositions in different binders, binder content, water content, and curing days. This study found that it is feasible to replace more than 50% of cement with SSA, while still achieving the required strength of 200 kPa for fill material at 28 days with an in-situ water content of 100%. The replacement of cement with a low-carbon and cost-free waste of SSA in marine deposit stabilization can significantly enhance the greenness and sustainability of construction.

Novel Polymer Composites for Lead-Free Shielding Applications.

Polymer nanocomposites have recently been introduced as lead-free shielding materials for use in medical and industrial applications. In this work, novel shielding materials were developed using low-density polyethylene (LDPE) mixed with four different filler materials. These four materials are cement, cement with iron oxide, cement with aluminum oxide, and cement with bismuth oxide. Different weight percentages were used including 5%, 15%, and 50% of the cement filler with LDPE. Furthermore, different weight percentages of different combinations of the filler materials were used including 2.5%, 7.5%, and 25% (i.e., cement and iron oxide, cement and aluminum oxide, cement and bismuth oxide) with LDPE. Bismuth oxide was a nanocomposite, and the remaining oxides were micro-composites. Characterization included structural properties, physical features, mechanical and thermal properties, and radiation shielding efficiency for the prepared composites. The results show that a clear improvement in the shielding efficiency was observed when the filler materials were added to the LDPE. The best result out of all these composites was obtained for the composites of bismuth oxide (25 wt.%) cement (25 wt.%) and LDPE (50 wt.%) which have the lowest measured mean free path (MFP) compared with pure LDPE. The comparison shows that the average MFP obtained from the experiments for all the eight energies used in this work was six times lower than the one for pure LDPE, reaching up to twelve times lower for 60 keV energy. The best result among all developed composites was observed for the ones with bismuth oxide at the highest weight percent 25%, which can block up to 78% of an X-ray.

High aspect ratio Na–Co-oxide ceramic filler composites with novel electrical and dielectric properties

Polymer composites with high aspect ratio Na–Co oxide ceramic filler – polymer matrix was investigated in this study. They demonstrate high dielectric permittivity, low dielectric loss tangent values which is useful for capacitive field grading and reversible voltage dependent electrical conductivity properties under an applied electric field which can be utilized for resistive field grading. These unique properties are useful for electrical stress control applications in power components. This study employs novel ceramic platelets as the varistor filler component in a polymer composite form, introducing a new class of materials to the world of electrical stress control technology. By minimizing the amount of varistor filler material required to very low levels (15 wt%), it is possible to develop lightweight non-linear dielectric composites that not only exhibit improved electrical characteristics but also make processing easier and open up new design space for making various components for electrical power applications. By utilizing novel NaxCoO2 (x < 1) ceramic fillers in composite form, we aim to contribute to the development of innovative nonlinear dielectric composites that can enhance the performance and processibility of various power system components under various working environments.

Non-contrast MRI and post-mastectomy silicone breast implant rupture: preventing false positive diagnoses.

Breast implants are not lifelong, with implant rupture being the third leading cause of revisional surgery in augmented women. Noncontrast MRI is a reliable tool to assess implant integrity; however, false positive and false negative diagnoses have been reported due to an incorrect interpretation of MRI signs. This study aims to investigate the incidence of these misleading results, comparing MRI findings with intraoperative surgical observations and exploring signs of nonunivocal interpretation. Between March 2019 and October 2022, our hospital, a referral center for breast cancer care, conducted 139 breast MRI examinations to evaluate implant integrity. Surgical intervention was deemed necessary for patients diagnosed with suspected or confirmed implant rupture at MRI. Those patients who did not undergo any surgical procedure (63 cases) or had surgery at different institutes (11 cases) were excluded. Among the 65 patients who underwent preoperative MRI and subsequent surgery at our institute, surgical findings confirmed the preoperative MRI diagnosis in 48 women. Notably, 17 women exhibited a discordance between MRI and surgical findings: three false negatives, 11 false positives and three possible ruptures not confirmed. Signs of nonunivocal or misleading interpretation were assessed on a patient-by-patient basis. The importance of obtaining detailed information about a patient's breast implant, including fill materials, number of lumens, manufacturer and shape, proved immensely beneficial for interpreting MRI signs accurately. Pre-MRI knowledge of implant details and a meticulous evaluation of non-univocal signs can aid radiologists in accurately assessing implant integrity, reducing the risk of unnecessary revisional surgeries, and potentially averting allegations of medical malpractice.

A comparative study on physicochemical properties of rice and starch of white rice, black rice and black glutinous rice

Rice is a staple food for Indonesians and Asians in general. It is rich in starch, a component that can be developed as a texture agent, filler, or raw material for edible films, encapsulation, or other products. The characteristics of the starch produced will determine its functional properties. This study aimed to characterize the physicochemical properties of rice and starch of white rice, black rice, and black glutinous rice. In this study, rice was extracted using an alkaline method to obtain rice starch. The processing of rice into starch can change some of its characteristics. A comparative study was also conducted on rice starch. The results showed that the starch contents of white, black, and black glutinous rice were 85.48; 86.67; and 83.56% (db). Black glutinous rice contains more amylopectin than black and white rice. Resistant starch in the rice fractions was greater than the amount of resistant starch in the starch fractions. Black rice contained anthocyanins of 323.85 mg/100 g, while the anthocyanins in black glutinous rice reached 219.35 mg/100 g. Although in very small amounts, anthocyanins were detected in black rice and black glutinous rice starch fractions. The starch fraction has much lower antioxidant activity compared to that in the form of rice. It appears on all types of rice. The peak viscosities of the starch of white rice, black rice, and black glutinous rice were 3627, 5448, and 5001 cP with pasting temperatures of 79.10°C, 80.60°C, and 80.90°C. Physicochemical and pasting properties of the rice fraction and the starch fraction from white, black, and black glutinous rice provide complete information to be used as a basis for the manufacture of food products.

Adipose tissue reconstruction facilitated with low immunogenicity decellularized adipose tissue scaffolds.

There is currently an urgent need to develop engineered scaffolds to support new adipose tissue formation and facilitate long-term maintenance of function and defect repair to further generate prospective bioactive filler materials capable of fulfilling surgical needs. Herein, adipose regeneration methods were optimized and decellularized adipose tissue (DAT) scaffolds with good biocompatibility were fabricated. Adipose-like tissues were reconstructed using the DAT and 3T3-L1 preadipocytes, which have certain differentiation potential, and the regenerative effects of the engineered adipose tissuesin vitroandin vivowere explored. The method improved the efficiency of adipose removal from tissues, and significantly shortened the time for degreasing. Thus, the DAT not only provided a suitable space for cell growth but also promoted the proliferation, migration, and differentiation of preadipocytes within it. Following implantation of the constructed adipose tissuesin vivo, the DAT showed gradual degradation and integration with surrounding tissues, accompanied by the generation of new adipose tissue analogs. Overall, the combination of adipose-derived extracellular matrix and preadipocytes for adipose tissue reconstruction will be of benefit in the artificial construction of biomimetic implant structures for adipose tissue reconstruction, providing a practical guideline for the initial integration of adipose tissue engineering into clinical medicine.

Waste Management of Red Mud and Fly Ash to Utilize in Road Subgrade Material

Red mud (RM) is a waste material obtained during the production of aluminum from bauxite minerals. RM causes environmental pollution due to its high alkaline properties. Therefore, RM materials are stored in waste reservoirs. As production continues, the number of required waste reservoirs increases day by day. This study aims to utilize RM waste material in construction structures to contribute to the economy. The research investigates the potential use of RM waste material as road fill material. RM was improved using another waste material of fly ash (FA) since RM has low strength. Atterberg limit tests, compaction tests, unconfined compression tests, CBR tests, and SEM analyses were conducted on stabilized RM samples. In the physical properties of stabilized RM, Atterberg limits and optimum moisture content increase and density decreases since FA content increases. In the mechanical properties of stabilized RM, unconfined compressive strength, initial and secant modulus of elasticity, and California bearing ratio increase and maximum peak strain decreases since FA content and curing period increase. SEM images prove the increase in mechanical properties due to the cementation products (CSH and CAH gels) formed in the microstructure of stabilized RM. The results showed that RM waste stabilized with FA can be used as road subgrade material.

Investigation of Mechanical, Thermal Properties of Camel wool Fiber and Chopped E-Glass Fiber Reinforced Epoxy Resin with and without Addition of Iron Oxide

Composites are an excellent alternative to metal alloys due to their high strength-to-weight ratio. It's awesome that researchers are working on biodegradable and recyclable fiber-reinforced composites. Each natural and synthetic fiber has advantages and disadvantages, but combining different fibers alters the properties of composite materials. In this project, we used camel wool fiber and chopped E-glass to make a hybrid composite with epoxy as the matrix. Combining different fibers in composite materials, it is possible to alter their properties and create materials with specific characteristics. Additionally, adding fillers to composites can further enhance their characteristics, such as improving strength, stiffness, and other mechanical and thermal properties. We also experimented with different amounts of iron oxide which resulted in these semi-biodegradable materials. The mechanical and thermal characteristics of these composites improved as the iron oxide powder content rose. The best part is that using iron oxide as a filler material can help reduce material costs. Key Words: Chopped E glass (CEG), Camel wool Fiber (CWF), Filler, Differential thermal analysis (DTA), Thermogravimetric analysis (TGA), Derivative thermogravimetry (DTG).

Outcome Assessment of Three Different Methods of Root-end Preparation and Filling Materials in Endodontic Surgery: A Comparative Clinical Prospective Study

Introduction: The technique of endodontic surgery had evolved tremendously in the recent years with introduction of new instruments and materials. Aim: This study aims to compare the clinical outcome of endodontic microsurgery using three different techniques with three different root-end filling materials for 16 months. Materials and Methods: A total of 45 maxillary incisors indicated for root-end surgery were selected for the study. They were enrolled into three groups, i.e. Group A (traditional [TRS]/heat burnished gutta-percha), Group B (concave [CON]/Retroplast), and Group C (cavity/DiaRoot BioAggregate), of 15 teeth each. The clinical and radiographic outcome was recorded at 1, 6, 12, and 16 months using various criteria. Statistical Analysis: The data were analyzed by one-way analysis of variance and Tukey’s post hoc test using SPSS V. 21 software (IBM Corp., Somers, NY, USA). Results: All patients had uneventful healing at the final follow-up. Radiological intratime analysis concluded a highly high significant (P &lt; 0.0001) decrease in the size of radiolucency between the three groups at the third recall visit. Intertime analysis recorded no significant decrease in radiolucency between Groups A and B, a significant decrease in B and C, and a highly significant decrease between Groups A and C at 12 months. Conclusions: There was no significant difference in the clinical outcome after endodontic surgery when comparing TRS/heat burnished gutta-percha, CON/Retroplast, and cavity/DiaRoot BioAggregate techniques at 16 months. However, cavity/DiaRoot BioAggregate resulted in significantly rapid and predictable healing at 12 months.

Fabrication of Nanocomposite Membrane with Nanomaterial Filler for Desalination

This review aims to provide a complete overview on the modification of polymer and biopolymer membranes into nanocomposite membrane materials. Fabrication of nanocomposite membranes is carried out by incorporating inorganic filler materials in nanoparticle sizes. Nanomaterials refer to the class of materials that consist of particulate substances with any dimension of less than 100 nm at least. The properties of nanomaterials include large specific surface area, crystalline structure, shape (that regulates most of its properties as well as their unique attributes), surface morphology, and assembling phenomena. This review primarily concentrates on the recent nanotechnology-based practices to enrich the outcomes of desalination on the footings of nanocomposites, developed practicing distinct nanomaterials. A classification for various forms of nanomaterials used for building nanocomposites has also been illustrated. Special emphasis has been given to the usage of nanocomposites constructed from several nanomaterials such as nanoparticles, nanotubes, nanoshells, nanofibers, nanocapsules, nanosheets and quantum dots, and how these nanocomposites have been utilized for desalination.

Electron-Beam Welding of Titanium and Ti6Al4V Using Magnetron-Sputtered Nb, V, and Cu Fillers

In this work, the results of an investigation of electron-beam-welded samples of commercially pure titanium (CP-Ti) and the titanium alloy Ti6Al4V (Ti64) using fillers of various beta-stabilizing elements (Nb, V, Cu) are presented. The fillers were in the form of deposited layers on each of the two specimens via DC magnetron sputtering. The specimens were then subjected to electron-beam welding (EBW) under the same technological conditions. The structure of the obtained welded joints was investigated by scanning electron microscopy (SEM). X-ray diffraction (XRD) was used to investigate the phase composition of the fusion zone (FZ). The study of the mechanical properties of the samples was carried out via tensile tests and microhardness measurements. The results showed a different influence of the used fillers on the structure and properties of the obtained joints, and in all cases, the yield strength increased compared to the samples welded using the same technological conditions without the use of filler material. In the case of using Nb and V as a filler, the typical transformation of titanium welds into elongated αTi particles along with α’-Ti martensitic structures was observed. The addition of a Cu filler into the structure of the welds resulted in a unification and refining of the structure of the last, which resulted in the improvement of the mechanical properties of the weld, particularly its ductility, which is a known issue where electron-beam welding is concerned.

Enhanced Dielectric Constant of PVDF-HFP/BFO Composite Films for Ferroelectric Applications

We have developed multiferroic Bismuth ferrite (BiFeO3, BFO) incorporated Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) polymer-ceramic composites through the solution casting method. The polymer-ceramic composites are fabricated by varying the composition of the BFO as a filler material ranging 5, 10, 15, 20, 25, 30, and 40 wt% into the PVDF-HFP polymer matrix. We have investigated the effect of BFO loading on the structural, morphological, spectroscopic, and dielectric properties by different characterization techniques. X-ray diffraction analysis indicates the presence of non-polar α- and polar β- phases of PVDF-HFP in the composites. Scanning electron microscope studies revealed the spherulite morphology and homogenous dispersion of BFO particles. The addition of BFO filler in PVDF-HFP matrix at various percentages has been studied to improve the polar β- phase of PVDF-HFP which may enhance ferroelectric properties. The dielectric studies at room temperature showed an increase in dielectric constant value from 9.5 (pure PVDF-HFP) to 21.08 (30% loaded BFO) at 100 Hz. It is also evident from the Fourier Transform- Infrared (FT-IR) spectra, that a maximum of 75.24% of β-fraction is observed for 30% loaded BFO composition. The enhanced properties of the fabricated materials suggest that they may be useful for polymer-ceramic capacitor applications. The results are discussed in detail.