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The global demand for ceramic materials with wide-ranging applications in the environment, precision tools, biomedical, and electronics, and environmental fields is on the increase. ...Several ceramic materials and methods of fabrication have been developed with task-specific properties. The material, the fabrication methods, and processing conditions impel characteristics including corrosion-resistant, outstanding optical and electrical properties, hardness and anti-aging. In this review, various materials for the preparation of ceramics and ceramic composites components were investigated to demonstrate the contribution of the materials and different fabrication methods to the properties of the ceramics components. The material properties, sintering temperature, casting technique, and pressure influences the ceramics grain size and porosity, which have an explicit effect on mechanical strength, corrosion-resistant, and optical properties of the ceramic components. The finishing of the ceramic components into a machinable shape requires careful attention to avoid defects. However, most conventional finishing methods are cost-intensive, hence, the need to commercialize 3-D printing for large scale and long-run applications. It is hoped that this review would propagate wider research on low cost and energy effective pathways to produce ceramics with dynamic properties, which can be applied in several fields with outstanding performance.
•Chinese Fir residue was used as reinforcement in addition to LDPE matrix.•MPOE, OMMT and their combinations were used as compatibilizers.•MPOE as a compatibilizer improve the impact strength.•The ...combination of MPOE and OMMT significantly improved the tensile strength.
The challenge to improve the interface in wood-plastic composite (WPC) has continued to remain a major setback in the field of wood technology. In this work, a novel hybrid compatibilizer system was developed. Chinese fir (Cunninghamia lanceolata) waste and low-density polyethylene were used as a reinforcing lignocellulosic material and matrix, respectively. Maleic anhydride grafted polyethylene octene elastomer (MPOE), octadecyl organically modified montmorillonite (OMMT) and their combinations were used as compatibilizers. The as-produced composites were characterized for their mechanical and physical properties using the SEM, FTIR, and mechanical testing. The result shows a significant increase in tensile strength of about 41.46 % when a mixture of MPOE and OMMT were used as compatibilizers. Moreover, the addition of MPOE led to the improvement of the impact strength by 26.89 %. Thus, the utilization of both compatibilizers offers an efficient route to improve the interaction and mechanical properties of WPC.
•Porous β-phase PVDF membranes were successfully fabricated by incorporating LiCl salt.•LiCl influences both PVDF chain arrangement and membrane structure.•Membrane performances were changed with the ...range of LiCl composition.•Polar β-phase PVDF membranes showed antifouling properties.
Polyvinylidene fluoride (PVDF) membranes, acclaimed for their outstanding chemical resistance, thermal stability, and mechanical properties, play a crucial role in diverse industrial purification applications. While various methods have been employed for fabricating PVDF membranes such as thermally induced, evaporation-induced, vapor-induced, and nonsolvent-induced phase separation processes, controlling the polarity of PVDF chains using these techniques remains challenging. Recent studies have shown that the nonpolar α-phase PVDF is susceptible to organic acid fouling owing to hydrophobic interactions, whereas the β-phase PVDF has demonstrated polarity and offers antifouling properties. Herein, porous PVDF membranes predominantly composed of the β-phase were successfully fabricated by incorporating a small amount of LiCl salt into the PVDF dope solution. The addition of LiCl influences ion–dipole moments between ions and PVDF during phase separation, simultaneously affecting the PVDF chain arrangement and membrane morphology. Since the LiCl additive alters both the pore size and structure of PVDF membranes, both freestanding and non-woven supported membranes were prepared and characterized to assess the effects of polarity and pore size on fouling tendency. Characterizations of prepared PVDF membranes revealed considerable changes in the PVDF polymorph, membrane morphology, pore size, and antifouling properties upon introducing the salt additive. Our findings imply that β-phase–dominant PVDF membranes can be effectively utilized in water purification applications.
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In this study, CaCu3Ti4O12 (CCTO) modified polyethersulfone (PES) HF membranes were prepared via dry-wet phase inversion by adding different concentration of CCTO particles (0–4 wt.%) ...in the dope solution. The synthesized PES/CCTO composites were characterized by viscosity measurement, scanning electron microscope, X-ray diffraction, contact angle, pore size, and pore size distribution. The flux and the photocatalytic activity of CCTO entrapped PES membranes were subsequently evaluated by crossflow ultrafiltration and the photodegradation of Rhodamine B (RhB) under UV irradiation, respectively. The pure water permeability of the composite membranes improved considerably upon the addition of CCTO owing to its slightly improved hydrophilicity and moderate pore size. The results also show that the PES/CCTO composite exhibited a higher photocatalytic activity, which was mainly attributed due to the crystallite size of CCTO particles.
Bone tissue engineering is one of the vital approaches used to tackle bone defects in the past decades. This approach is a risk-free alternative to conventional bone graft substitutes, such as ...autografts, allografts, and xenografts. Silicate bioceramics have improved mechanical properties and biological performances compared with phosphate-based ceramics. However, their brittleness limits their application in load-bearing sites. Therefore, silicate-based ceramics have been used in combination with several polymers in the form of a composite scaffold. This review article summarizes the influence of silicate ceramics on the mechanical, cytocompatibility, and bioactivity of polymeric-based scaffold for bone tissue engineering application.
A schematic of composite fabrication by the incorporation of silicate ceramics into a polymer-based scaffold. The composite scaffold leads to two major effects: improvement in mechanical properties and enhancement of biological performance. As implantation proceeds, implant degradation occurs due to the apatite formation resulting from the ionic dissolution products such as Ca
2+
, Mg
2+,
and Si
4+
from silicate-based ceramics. These ionic dissolution products positively affect bone cell proliferation, differentiation, and spreading. Consequently, osteogenesis leads to new bone formation and growth. This finally increases the strength of the implant area, approaching that of the host repair area. Besides, the composite scaffold could have mechanical strength close to those of natural bone. This match of mechanical properties between the composite scaffold and host bone supports bone tissue ingrowth via intrapressure stimulus, contributing to bone tissue ingrowth.
Statement of significance Human bone is known as a composite material comprised of hydroxyapatite (HA) as a ceramic phase and collagen as a polymer phase. The development of hierarchical porous scaffolds to imitate the structure and properties of human natural bone is one of the major challenges in tissue engineering. Although bioactive ceramics (particularly silicate-based ceramics) have been known as promising biomaterials due to their comparable chemical compositions to those of human bone; nonetheless, their low strength limits their biomedical applications in load-bearing sites. On the other hand, polymeric biomaterials feature some disadvantages such as inadequate mechanical strength, low bioactivity, lack of binding sites for cell adhesion, and acidic degradation products. Therefore, composites are of great importance to overcome the above-mentioned shortcomings by combining the excellent ductility of biopolymers and bioactivity of ceramics. This review discusses on the influence of silicate ceramics on the mechanical, cytocompatibility, and bioactivity properties of polymer-based scaffold for potential application in bone tissue engineering.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
In the present work, a highly efficient mixed matrix membrane (MMM) for humic acid (HA) removal was developed. Multiwalled carbon nanotubes (MWCNTs) were functionalized in the presence of ...3-methacryloxypropyl trimethoxysilane using the co-condensation method and were subsequently loaded with TiO2 (prepared via the sol–gel route). The as-prepared material was then incorporated into a PES polymer solution to prepare a fMWCNT-TiO2/PES hybrid membrane via non-solvent induced phase inversion. The microstructure of the membrane was characterized using Fourier transform infrared spectroscopy, atomic force microscopy, scanning electron microscopy, water contact angle, thickness, porosity, and pore size. The fMWCNT-TiO2/PES hybrid membrane was tested for the removal of HA and antifouling performance. The results show that the surface hydrophilicity of the membranes was greatly improved upon the addition of the fMWCNT-TiO2 particles. The results show that 92% of HA was effectively removed after 1 h of filtration. In comparison with pristine membrane, the incorporation of fMWCNT-TiO2 nanoparticles led to enhanced pure water flux (99.05 L/m2 h), permeate flux (62.01 L/m2 h), higher HA rejection (92%), and antifouling improvement (RFR: 37.40%, FRR: 86.02%). Thus, the fMWCNT-TiO2/PES hybrid membrane is considered to be a great potential membrane for the improvement of ultrafiltration membranes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Due to increasing load and characteristic stagnation and fluctuations of existing generation systems capacity, the reliability assessment of generation systems is crucial to system adequacy. ...Furthermore, a rapid load increase could amount to a consequent sudden deficit in the generation supply before the next scheduled assessment. Hence, a reliability assessment is conducted at regular and close intervals to ensure adequacy. This study simulates and establishes the relationship between the load growth and generation capacity using the generation and load data of the IEEE reliability test system (IEEE RTS ‘96 standard). The generation capacity states and the risk model were obtained using the sequential Monte Carlo simulation (MCS) method. The load was gradually increased stepwise and is simulated against the constant generation capacity. In each case, the reliability index was recorded in terms of loss-of-load evaluation (LOLE). The recorded reliability index was thereafter fitted with the load-growth trend by the linear regression approach. A predictive assessment approach is thereafter proffered through the obtained fitting equation. In addition, a reliability threshold is effectively determined at a yield point for a reliability benchmark.
The relationships among varying bore fluid compositions containing ethanol/water were studied. The ethanol composition was varied in the ratio of 0%, 25%, 50%, 75% and 100%. The membrane dope ...solutions were prepared from 17.25 wt% polyethersulfone (PES), 0.75 wt% polyethylene glycol (PEG), 3 wt% silicon dioxide sol and 78.25 wt% of 1-methyl-2-pyrrolidone (NMP) via dry-jet spinning process. The membranes’ morphology as a result of varying ethanol ratio in the bore fluid composition was characterized and their effects on crude oil/water emulsion separation were evaluated. Results show that the membrane pore size and porosity decreased with increasing ethanol content in the bore fluid mixture, whereas the inner wall thickness of fibers increased. Furthermore, an increase in ethanol concentration also resulted in a slight increase in water contact angle. The use of 100/0 of ethanol/water resulted in UF membranes with the lowest performance. On the other hand, bore fluid mixture containing 25/75 ethanol/water produced membrane with the best performance for crude oil/water separation. Overall, the use of bore fluid mixture containing 25/75 ethanol/water mixture was found to be a powerful way to tune the morphological properties and performance of HF membrane.
The blending of additives in the polyethersulfone (PES) matrix is an important approach in the membrane industry to reduce membrane hydrophobicity and improve the performance (flux, solute rejection, ...and reduction of fouling). Several (hydrophilic) modifications of the PES membrane have been developed. Given the importance of the hydrophilic modification methods for PES membranes and their applications, we decided to dedicate this review solely to this topic. The types of additives embedded into the PES matrix can be divided into two main categories: (i) polymers and (ii) inorganic nanoparticles (NPs). The introduced polymers include polyvinylpyrrolidone, chitosan, polyamide, polyethylene oxide, and polyethylene glycol. The introduced nanoparticles discussed include titanium, iron, aluminum, silver, zirconium, silica, magnesium based NPs, carbon, and halloysite nanotubes. In addition, the applications of hydrophilic PES membranes are also reviewed. Reviewing the research progress in the hydrophilic modification of PES membranes is necessary and imperative to provide more insights for their future development and perhaps to open the door to extend their applications to other more challenging areas.
The blending of additives in the polyethersulfone (PES) matrix is an important approach in the membrane industry to reduce membrane hydrophobicity and improve the performance (flux, solute rejection, and reduction of fouling).
Layered titania (L-TiO
) holds great potential for potassium-ion batteries (PIBs) and sodium-ion batteries (SIBs) due to their high specific capacity. Synthesizing L-TiO
functional materials for ...high-capacity and long cyclability battery remains challenging due to the unstable and poor conductivity of bare L-TiO
. In nature, plant growth can stabilize land by preventing sands from dispersing following desertification. Inspired by nature's "sand-fixation model," Al
"seeds" are in situ grown on layered Ti
C
T
"land." Subsequently, NH
-MIL-101(Al) "plants" with Al as metal nodes are grown on the Ti
C
T
"land" by self-assembly. After annealing and etching processes (similar to desertification), NH
-MIL-101(Al) is transformed into interconnected N/O-doped carbon (MOF-NOC), which not only acts as a plant-like function to prevent the pulverization of L-TiO
transformed from Ti
C
T
but also improves the conductivity and stability of MOF-NOC@L-TiO
. Al species are selected as seeds to improve interfacial compatibility and form intimate interface heterojunction. Systematic ex situ analysis discloses that the ions storage mechanism can be endowed by mixed contribution of non-Faradaic and Faradaic capacitance. Consequently, the MOF-NOC@L-TiO
electrodes exhibit high interfacial capacitive charge storage and outstanding cycling performance. The interface engineering strategy inspired by "sand-fixation model" provides a reference for designing stable layered composites.
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