Promising New Horizons in Medicine: Medical Advancements with Nanocomposite Manufacturing via 3D Printing.

Three-dimensional printing technology has fundamentally revolutionized the product development processes in several industries. Three-dimensional printing enables the creation of tailored prostheses and other medical equipment, anatomical models for surgical planning and training, and even innovative means of directly giving drugs to patients. Polymers and their composites have found broad usage in the healthcare business due to their many beneficial properties. As a result, the application of 3D printing technology in the medical area has transformed the design and manufacturing of medical devices and prosthetics. Polymers and their composites have become attractive materials in this industry because of their unique mechanical, thermal, electrical, and optical qualities. This review article presents a comprehensive analysis of the current state-of-the-art applications of polymer and its composites in the medical field using 3D printing technology. It covers the latest research developments in the design and manufacturing of patient-specific medical devices, prostheses, and anatomical models for surgical planning and training. The article also discusses the use of 3D printing technology for drug delivery systems (DDS) and tissue engineering. Various 3D printing techniques, such as stereolithography, fused deposition modeling (FDM), and selective laser sintering (SLS), are reviewed, along with their benefits and drawbacks. Legal and regulatory issues related to the use of 3D printing technology in the medical field are also addressed. The article concludes with an outlook on the future potential of polymer and its composites in 3D printing technology for the medical field. The research findings indicate that 3D printing technology has enormous potential to revolutionize the development and manufacture of medical devices, leading to improved patient outcomes and better healthcare services.

Retrospective on Exploring MXene-Based Nanomaterials: Photocatalytic Applications.

Nanostructural two-dimensional compounds are grabbing the attention of researchers all around the world. This research is progressing quickly due to its wide range of applications in numerous industries and enormous promise for future technological breakthroughs. Growing environmental consciousness has made it vital to treat wastewater and avoid releasing hazardous substances into the environment. Rising consumer expectations have led to the emergence of new, frequently nonbiodegradable compounds. Due to their specific chemical and physical properties, MXenes have recently been identified as promising candidates. MXenes are regarded as a prospective route for environmental remediation technologies, such as photocatalysis, adsorption, and membrane separation, and as electrocatalytic sensors for pollution recognition because of their high hydrophilicity, inherent chemical nature, and robust electrochemistry. The development of catalysts based on MXene materials for the photocatalytic breakdown of pharmaceutical wastes in polluted water is critically evaluated in this study. With an emphasis on the degradation mechanism, the photocatalytic degradation of antibiotics using MXenes and MXene-based nanocomposites is explained in depth. We emphasize the significant difficulties in producing MXenes and their composites, as well as in the degradation of drugs. The successful use of MXenes in water filtration and suggestions for future study are also presented.

3D Printing of Flexible Mechanical Metamaterials: Synergistic Design of Process and Geometric Parameters.

Mechanical metamaterials with ultralight and ultrastrong mechanical properties are extensively employed in various industrial sectors, with three-periodic minimal surface (TPMS) structures gaining significant research attention due to their symmetry, equation-driven characteristics, and exceptional mechanical properties. Compared to traditional lattice structures, TPMS structures exhibit superior mechanical performance. The mechanical properties of TPMS structures depend on the base material, structural porosity (volume fraction), and wall thickness. Hard rigid lattice structures such as Gyroid, diamond, and primitive exhibit outstanding performance in terms of elastic modulus, energy absorption, heat dissipation, and heat transfer. Flexible TPMS lattice structures, on the other hand, offer higher elasticity and recoverable large deformations, drawing attention for use in applications such as seat cushions and helmet impact-absorbing layers. Conventional fabrication methods often fail to guarantee the quality of TPMS structure samples, and additive manufacturing technology provides a new avenue. Selective laser sintering (SLS) has successfully been used to process various materials. However, due to the layer-by-layer manufacturing process, it cannot eliminate the anisotropy caused by interlayer bonding, which impacts the mechanical properties of 3D-printed parts. This paper introduces a process data-driven optimization design approach for TPMS structure geometry by adjusting volume fraction gradients to overcome the elastic anisotropy of 3D-printed isotropic lattice structures. Experimental validation and analysis are conducted using TPMS structures fabricated using TPU material via SLS. Furthermore, the advantages of volume fraction gradient-designed TPMS structures in functions such as energy absorption and heat dissipation are explored.

Influence of Exposure Period and Angle Alteration on the Flexural Resilience and Mechanical Attributes of Photosensitive Resin.

Despite the large number of studies addressing the effect of acrylic resin polymerization concerning flexural properties, limited research has been conducted on the manufacturing impact on a polymer's mechanical properties. Photosensitive resinous materials are used in various engineering applications where they may be exposed to multiple detrimental environments during their lifetime. Therefore, there is a need to understand the impact of an environment on the service life of resins. Thus, flexural tests were conducted to study the effects of exposure time and angle on the flexural strength of resins. Herein, the main objective was to explore the strength, stability, and flexural durability of photosensitive resin (EPIC-2000ST) fabricated at different exposure times (E) and angle deviation varying from 0° to 85° with a 5° increment. The samples in circular rings were manufactured and divided into five groups according to their exposure time (E): 10 s, 20 s, 30 s, 40 s, and 50 s. In each exposure time, we designed rings via SolidWorks software and experimentally fabricated at different oblique angles (OA) varying from 0° to 85° with a 5° increment during each fabrication, i.e., OA = 0°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, and 85°. Flexural strength was evaluated using a three-point bending test. Optical electron microscopy was used to examines the samples' exterior, interior, and ruptured surfaces. Our experimental analysis shows that flexural strength was significantly enhanced by increasing exposure time and at higher oblique angles. However, at lower angles and less exposure time, mechanical flexural resilience declines.

Removal of persistent acetophenone from industrial waste-water via bismuth ferrite nanostructures.

Increasing water pollution is a severe problem in densely industrialized countries. Nanomaterials provide strong potentials for the efficient elimination of organic pollutants due to their beneficial properties. Advancement in water purification is required to more efficiently remove the emerging organic contaminants, especially in pharmaceuticals wastes such as acetophenone, which shows high solubility in industrial wastewaters. Bismuth ferrite-based nanostructures were fabricated using a novel double solvent sol-gel method. The phase purity and crystallinity of bismuth ferrite were confirmed using XRD and further endorsed by TEM analysis. The SEM and XPS were used to study the particle sizes and presence of co-dopants on the Bi and Fe-sites of bismuth ferrite. After co-doping, the band-gap engineering of pure bismuth ferrites was accomplished by reducing it from 2.06 eV to 1.45 eV, likely attributing to the creation of shallow traps for the incoming photo-generated charge carriers. In particular, the Bi0.90Gd0.10Fe0.95Sn0.05 and Bi0.95Sm0.05Fe0.75Mn0.25 successfully eliminated up to 98% of acetophenone from polluted water in 3 h by irradiation of visible-light. These results reveal the suitability of the co-doped bismuth ferrites photocatalysts for the practical removal of pharmaceutical contaminants in hazardous industrial wastewater. The photodegradation of acetophenone by bismuth ferrite nanostructures with potentially long-lasting reusability demonstrate its potential as an advanced photocatalyst for wastewater treatment.

Monolayer and Bilayer Formation of Molecular 2D Networks Assembled at the Liquid/Solid Interfaces by Solution-Based Drop-Cast Method.

In recent years, extending self-assembled structures from two-dimensions (2D) to three-dimensions (3D) has been a paradigm in surface supramolecular chemistry and contemporary nanotechnology. Using organic molecules of p-terphenyl-3,5,3',5'-tetracarboxylic acid (TPTC), and scanning tunneling microscopy (STM), we present a simple route, that is the control of the solute solubility in a sample solution, to achieve the vertical growth of supramolecular self-assemblies, which would otherwise form monolayers at the organic solvent/graphite interface. Presumably, the bilayer formations were based on π-conjugated overlapped molecular dimers that worked as nuclei to induce the yielding of the second layer. We also tested other molecules, including trimesic acid (TMA) and 1,3,5-tris(4-carboxyphenyl)-benzene (BTB), as well as the further application of our methodology, demonstrating the facile preparation of layered assemblies.

Supramolecular Chemistry: Host-Guest Molecular Complexes.

In recent times, researchers have emphasized practical approaches for capturing coordinated and selective guest entrap. The physisorbed nanoporous supramolecular complexes have been widely used to restrain various guest species on compact supporting surfaces. The host-guest (HG) interactions in two-dimensional (2D) permeable porous linkages are growing expeditiously due to their future applications in biocatalysis, separation technology, or nanoscale patterning. The different crystal-like nanoporous network has been acquired to enclose and trap guest molecules of various dimensions and contours. The host centers have been lumped together via noncovalent interactions (such as hydrogen bonds, van der Waals (vdW) interactions, or coordinate bonds). In this review article, we enlighten and elucidate recent progress in HG chemistry, explored via scanning tunneling microscopy (STM). We summarize the synthesis, design, and characterization of typical HG structural design examined on various substrates, under ambient surroundings at the liquid-solid (LS) interface, or during ultrahigh vacuum (UHV). We emphasize isoreticular complexes, vibrant HG coordination, or hosts functional cavities responsive to the applied stimulus. Finally, we critically discuss the significant challenges in advancing this developing electrochemical field.

Bismuth vanadate/MXene (BiVO4/Ti3C2) heterojunction composite: enhanced interfacial control charge transfer for highly efficient visible light photocatalytic activity.

We have synthesized BiVO4/Ti3C2 nanocomposite via a low-cost hydrothermal method and investigate its photocatalytic degradation activity against monoazo (methyl orange) and diazo dye (Congo red) in an aqueous solution under visible light. The physiochemical characterization exhibited that the addition of MXene in pristine BiVO4 nanocomposite led to an increase in specific surface area and reduction in optical band gap energy. MXene also helps in enhancing visible light response via a higher electron-hole pair generation rate and long lifetime. The synthesized BiVO4/Ti3C2 heterojunction composite exhibited 99.5 % degradation efficiency within 60 min for Congo red and 99.1 % for methyl orange solution in 130 min owed to a large specific surface area (1.79 m2/g), reduced band gap (1.99 eV), and low recombination rate of charge carriers. The chemical mechanism for BiVO4/Ti3C2 nanocomposite proposes that Ti3C2 role-plays as electron capture because of the higher potential of MXenes, tuning band gap energy which paves the way to excellent photocatalytic action. This work opens a new basis for developing Ti3C2 based promising and inexpensive co-catalyst for efficient solar utilization in photocatalytic-related applications in the future.

Construction of 1T-MoS2 quantum dots-interspersed (Bi1-x Fe x )VO4 heterostructures for electron transport and photocatalytic properties.

The present study reports trigonal phase molybdenum disulfide quantum dots (MoS2/QDs)-decorated (Bi1-x Fe x )VO4 composite heterostructures. Initially, (Bi1-x Fe x )VO4 heterostructure nanophotocatalysts were synthesized through the hydrothermal method decorated with 1T-MoS2 via a sonication process. 1T-MoS2@(Bi1-x Fe x )VO4 heterostructures were characterized in detail for phase purity and crystallinity using XRD and Raman spectroscopy. The Raman mode evaluation indicated monoclinic, mixed monoclinic-tetragonal and tetragonal structure development with increasing Fe concentration. For physiochemical properties, SEM, EDX, XPS, PL, EPR, UV-visible and BET techniques were applied. The optical energy band gaps of 1T-MoS2@(Bi1-x Fe x )VO4 heterostructures were calculated using the Tauc plot method. It shows a blue shift initially within a monoclinic structure then a red shift with an increase of Fe concentration. 1T-MoS2@(Bi40Fe60)VO4 with 2 wt% of 1T-MoS2-QDs carrying a mixed phase exhibited higher photocatalytic activity. The enhanced photocatalytic activity is attributed to the higher electron transportation from (Bi1-x Fe x )VO4 surface onto 1T-MoS2 surface, consequently blocking the fast electron-hole recombination within (Bi1-x Fe x )VO4. 1T-MoS2 co-catalyst interaction with (Bi1-x Fe x )VO4 enhanced the light absorption in the visible region. The close contact of small 1T-MoS2-QDs with (Bi1-x Fe x )VO4 develops a high degree of crystallinity, with fewer defects showing mesoporous/nanoporous structures within the heterostructures which allows more active sites. Herein, the mechanism involved in the synthesis of heterostructures and optimum conditions for photocatalytic degradation of crystal violet dye are explored and discussed thoroughly.

Recent progress in hybrid perovskite solar cells through scanning tunneling microscopy and spectroscopy.

Currently, sustainable renewable energy sources are urgently required to fulfill the cumulative energy needs of the world's 7.8 billion population, since the conventional coal and fossil fuels will be exhausted soon. Photovoltaic devices are a direct and efficient means to produce a huge amount of energy to meet these energy targets. In particular, hybrid-perovskite-based photovoltaic devices merit special attention not only due to their exceptional efficiency for generating appreciable energy but also their tunable band gaps and the ease of device fabrication. However, the commercialization of such devices suffers from the instability of the compositional materials. The cause of instability is the perovskite's structure and its morphology at the sub-molecular level; thereby revealing and eliminating these instabilities are a striking challenge. To address this issue, scanning tunneling microscopy/spectroscopy (STM/STS) presents a comprehensive method to allow the visualization of the morphology and electronic structure of materials at atomic-level resolution. Here, we review the recent developments of perovskite-based solar cells (PSCs), the STM/STS analysis of photoactive halide/hybrid and oxide materials, and the real-time STM/STS investigation of electronic structures with defects and traps that are believed to mainly affect device performances. The detailed STM/STS analysis can facilitate a better understanding of the properties of materials at the nanoscale. This informative study may hold great promise to advance the development of stable PSCs under atmospheric conditions.

Nanoscale tailoring of supramolecular crystals via an oriented external electric field.

The oriented external electric field of a scanning tunneling microscope (STM) has recently been adapted for controlling the chemical reaction and supramolecular phase transition at surfaces with molecular precision. However, to date, advance controls using such electric-fields for crystal engineering have not been achieved yet. Here, we present how the directional electric-field of an STM can be utilized to harness supramolecular crystallization on a solid surface. We show that a glass-like random-tiling assembly composed of p-terphenyl-3,5,3',5'-tetracarboxylic acid can transform into close-packed periodic assemblies under positive substrate bias conditions at the liquid/solid interface. Importantly, the nucleation and subsequent crystal growth for such field-induced products can be artificially tailored at the early stage in a real-time fashion. Through this method, we were able to produce a two-dimensional supramolecular single crystal. The as-prepared crystals with apparent brightness are ascribed to a spectroscopic feature linked to the electron density of states, which is thus strongly STM bias dependent.

Influence of Zn+2 Doping on Ni-Based Nanoferrites; (Ni1-x ZnxFe2O4).

Nickel zinc nanoferrites (Ni1-xZnxFe2O4) were synthesized via a chemical co-precipitation method having stoichiometric proportion (x) altering from 0.00 to 1.00 in steps of 0.25. The synthesized nanoparticles were sintered at 800 °C for 12 h. X-ray diffraction patterns illustrate that the nanocrystalline cubic spinel ferrites have been obtained after sintering. The Scherrer formula is used to evaluate the particle size using the extreme intense peak (311). The experimental results demonstrate that precipitated particles' size was in the range of 20-60 nm. Scanning electron microscopy (SEM) is used to investigate the elemental configuration and morphological characterizations of all the prepared samples. FTIR spectroscopy data for respective sites were examined in the range of 300-1000 cm-1. The higher frequency band ν1 were assigned due to tetrahedral complexes while lower frequency band ν2 were allocated due to octahedral complexes. Our experimental results demonstrate that the lattice constant a0 increases while lattice strain decreases with increasing zinc substitution in nickel zinc nanoferrites.

Hydrophobic surface modified HfO2 antireflective coatings.

A multifunctional antireflective (AR) thin film is always a prerequisite for growing high-tech applications. Herein we proposed a surface modification technique to transform the hydrophilic behaviour of HfO2 AR nanofilms into hydrophobic without influencing the nanostructure, morphology, refractive index (η) or AR efficacy of HfO2 nanofilms. Our experimental results demonstrate that the fabricated HfO2 AR nanofilms retain its AR efficiency after surface modification to <1% in the visible wavelength range (450-700 nm) on FTO and sapphire. HfO2 AR nanofilms show hydrophilic behaviour before surface modification with a water contact angle (WCA) of 29° on FTO and 22° on sapphire. However, after surface treatment, they display hydrophobic nature θ w > Î¸ > 90° with a contact angle of (127°-130°). The experimental result demonstrates that the η of the thin layers fabricated at deposition angle 0°, 80°, and 88° before and after modification remains almost the same. HfO2 AR nanofilms exhibit long term AR permanency as AR efficiency measured within a year practically displays the equivalent reflectance curves similar to as deposit AR thin films, i.e. <1% in the wavelength range of 450-700 nm. We proposed a cost-effective procedure to make hydrophilic AR films to show non-wetting behaviour for its long-term exposure in a moist, damp environment without affecting the refractive index of AR thin film.

Influence of Refractive Index on Antireflectance Efficiency of Thin Films.

In today's world, scientific development is tremendously strengthened by imitating natural processes. This development remarkably validates progressive and efficient operation of multifunctional thin films in variable ecological circumstances. We use TFCalc thinfilm software, a reliable and trustworthy simulation tool, to design antireflective (AR) coatings for solar cells that can operate in varying environmental conditions and can be functional according to user-defined conditions. Silicon nearly reflects 36% light in the 550 nm wavelength region, causing a significant loss in solar cell efficiency. We used silicon as the substrate on which we designed and fabricated a trilayer inorganic oxide AR thin films, and this reduced it reflectance to <4% in the 300~800 nm wavelength range. Because of their distinguishing physical physiognomies, we used a combination of different inorganic oxides, comprising high-, low-, and medium-refractive indices, to model AR coatings in the desired wavelength range. Experimental implementation of the designed AR thin films in the present study unlocks new techniques for production of competent, wideband-tunable AR coatings that are applicable in high-performance photovoltaic applications.

Visible light assisted photocatalytic degradation of crystal violet dye and electrochemical detection of ascorbic acid using a BiVO4/FeVO4 heterojunction composite.

A BiVO4/FeVO4 nanocomposite photocatalyst was successfully synthesized via a hydrothermal method. The prepared heterojunction photocatalyst was characterized physically and chemically using XRD, SEM, EDX, XPS, BET, FT-IR, Raman, UV-vis DRS, EPR and photoluminescence techniques. BiVO4/FeVO4 was explored for its photocatalytic activity by the decomposition of crystal violet (CV) organic dye under visible radiation. This experiment showed that BiVO4/FeVO4 at a ratio of 2 : 1 completely degrades CV within 60 min. In addition, BiVO4/FeVO4 was investigated for the electrochemical detection of the useful analyte ascorbic acid using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry techniques. This work reveals the potential of the BiVO4/FeVO4 nanocomposite for applications in environmental disciplines as well as in biosensing.

Synthesis of Zn3(VO4)2/BiVO4 heterojunction composite for the photocatalytic degradation of methylene blue organic dye and electrochemical detection of H2O2.

In this study, a Zn3(VO4)2/BiVO4 heterojunction nanocomposite photocatalyst was prepared using a hydrothermal route with different molar concentration ratios. The as-synthesized nanophotocatalyst was characterized using XRD, SEM, EDS, XPS, FT-IR, Raman, BET, UV-vis DRS, EPR and PL. The effect of molar ratio on composition and morphology was studied. The as-prepared nanocomposite exhibited excellent photocatalytic response by completely degrading the model pollutant methylene blue (MB) dye in 60 min at molar concentration ratio of 2 : 1. In basic medium at pH 12, the Zn3(VO4)2/BiVO4 nanocomposite degrades MB completely within 45 min. The nanocomposite was also successfully used for the electrochemical detection of an important analyte hydrogen peroxide (H2O2). This study opens up a new horizon for the potential applications of Zn3(VO4)2/BiVO4 nanocomposite in environmental wastewater remediation as well as biosensing sciences.

Al2O3 Encapsulated Teflon Nanostructures with High Thermal Stability and Efficient Antireflective Performance.

Scientific advancement is highly inspired and imitative of natural phenomenon's, which exhibits extremely developed and well-organized nanostructures to cope with challenges under different environmental circumstances, such as moth eyes protuberances for efficient antireflective (AR) performance. Innovative researches have been performed in the past to exterminate the undesirable reflectance in common optical components and optoelectronic industrial applications by biomimetic and replicating moth eye nanostructures creating gradient effect using metal oxides, composites, or polymers in multilayer AR coatings. However, in few multilayer AR designs, the properties mismatch at interfaces, high cost, low mechanical durability, wetting issues, or thermal stability bounds their practical applicability. Herein, we develop an approach for fabricating efficient, high-performance Teflon (polytetrafluoroethylene [PTFE]) AR nanostructures for glass-based supporting materials. Nanotailoring, the morphology and structure of PTFE, have been efficaciously carried out for fabricating high-performance AR coatings according to predicted optical simulation. The total reflectance from polymer AR coating lessens to <0.05% in a visible wavelength range which according to our best knowledge seems to be the superior AR performance by a polymer coating ever reported. Furthermore, the fabricated polymer AR coatings are omnidirectional, mechanically durable, and thermally stable up to 200 °C. Moreover, we modify and tune the refractive index of PTFE from 1.34 to 1.156 by inducing porosity and changing deposition angle.

Antireflective coatings with enhanced adhesion strength.

The importance of tuning refractive index in a multilayer antireflection coating (ARC) system can not be denied. In practical applications, regulation of refractive index is complex due to limited choice and availability of appropriate materials for the trilayer AR coating assembly. To overcome this issue, we used a single inorganic material, HfO2, for the construction of a trilayer AR light harvesting moth eye, resembling hierarchical nanostructure coatings, for exploring new generation photovoltaics and optoelectronic devices. In the trilayer AR HfO2 (TAR-H) assembly, using a glancing angle deposition technique (GLAD), the dense bottom layer was steadily changed into a spongy middle layer that further changed to a highly porous top layer micmiking a moth eye, reducing the refractive index of the coating from 1.87 to 1.30. The broadband omnidirectional properties of the TAR-H coating, with superior thermal stability and improved scratch resistance, in the visible wavelength range were experimentally demonstrated. The TAR-H coating on FTO and sapphire substrates achieved reflectance of up to <1% in the visible wavelength range.