Nanomanufacturing

Recently, several strategies have been adopted for the cesium lead halide, CsPbX₃ (X = Cl, Br, and/or I), crystal growth with a perovskite-type structure, paving the way for the further development of innovative optoelectronic and photovoltaic applications. The optoelectronic properties of advanced materials are controlled, in principle, by effects of morphology, particle size, structure, and composition, as well as imperfections in these parameters. Herein, we report a detailed investigation, using theoretical and experimental approaches to evaluate the structural, electronic, optical, and electrical properties of CsPbX₃ microcrystals. The microcrystals are synthesized successfully using the hydrothermal method without surfactants. This synthetic approach also offers an easy upscaling for perovskite-related material synthesis from low-cost precursors. Lastly, in this direction, we believe that deeper mechanistic studies, based on the synergy between theory and practice, can guide the discovery and development of new advanced materials with highly tailored properties for applications in optoelectronic devices, as well as other emergent technologies. Full article

Chloride–iodide perovskites have received substantial interest due to their better photovoltaic performance compared to pure iodide ones. The superior properties of chloride–iodide perovskites boost photovoltaic performance. However, quantifying the Cl composition in perovskite films remains challenging. Hence, it is not easy to correlate the Cl quantity with the improved photovoltaic performance. Considering this critical issue, it is still necessary to determine the correlation between the Cl quantity and the improved photovoltaic performance to solve this puzzle. Here, a critical review is presented showcasing the significant impacts of the Cl quantity on chloride–iodide perovskites and related solar cell devices. This review provides an up-to-date picture of different strategic methods to overcome the challenges of Cl incorporation in I-based perovskites, aiming to improve photovoltaic performance. Finally, some valuable remedies are prescribed for potential future research strategies to study the photovoltaic performance of chloride–iodide perovskite solar cells. Hopefully, this review will be a noteworthy scientific contribution to the advancement of the continuous progress of perovskite solar cells. Full article

It has been shown that defect-free Stone–Wales (SW) free few-layer graphene (FLG) can be obtained by carbonizing lignin under conditions of self-propagating high-temperature synthesis (SHS). The obtained few-layer graphene was used as a modifying additive for pyrotechnic compositions. It was found that the addition of 2.5 mass % of few-layer graphene synthesized from lignin to a pyrotechnic complex based on porous silicon and fluoropolymer leads to a significant increase in the combustion intensity of pyrotechnic compositions. Full article

The second most significant cause of cancer-related mortality and morbidity in the United States is colorectal cancer (CRC), the third most diagnosed malignancy. People over 50 have an increased risk of CRC everywhere in the world. Genetic and environmental risk factors significantly influence CRC development. Early detection is critical in the treatment and prevention of CRC. The population’s incidence rate of CRC is currently reduced by screening techniques and medicines, although recurrence of the disease may result from the cancer’s ability to spread locally. Consequently, the difficulty is in finding a different treatment for CRC. Nanotechnology is crucial for cancer treatment because it allows for the delivery of targeted chemotherapies to cancer cells directly and with greater therapeutic potency. Nanoemulsions have broad application in pharmaceutics, cosmetics, and food; their outstanding properties include enhanced dispersion of active hydrophobic components, small size, high surface area per unit volume, and improved absorption in cancer treatment. The present review highlights formulation aspects, preparation methods, and characterization techniques. We also provide a critical analysis of recent developments in nanoemulsions in colorectal cancer treatment that hold promise in delivering nanoemulsions in colorectal treatment. Full article

Nowadays, Y-shaped non-fullerene acceptors become increasingly important in organic photovoltaics (OPV). Their use in binary and ternary bulk heterojunction composites continuously pushes up the efficiency of OPV devices. However, the mechanism of OPV performance enhancement by the third component of a ternary composite is rarely understood. In the present work, pulse EPR technique was used to reveal the similarities and the differences of photoinduced charge separation process in binary PM6/Y6 and ternary PM6/Y6:Y-T composites, where PM6 is polymer donor, Y6 and Y-T are different non-fullerene acceptors. Out-of-phase electron spin echo signal was detected for both composites, which is the signature of the charge-transfer state (CT state) formed at the donor/acceptor interface upon exciton splitting. Nearly identical distribution of the distances between the electron and the hole constituting the CT state was obtained for these composites from the analysis of this signal. In both cases the average electron-hole distance was 3.5 nm. It implies that OPV efficiency increase with Y-T addition is not caused by the increased probability of CT state dissociation followed by free charge generation for PM6/Y6:Y-T composite. Full article

In conventional chemical and electrochemical oxidation methods, it is very difficult to control the active centers, and the average prepared polymers are short and wide. The use of an electric field creates the most stable intermediate form of active centers, as well as permitting a longer half-life. Therefore, this increases the physical resistance and electrical conductivity of the polymer. In this paper, polycarbazole nanofibers were prepared using an electric field, reporting on its influences on the polymerization of carbazole. Therefore, its electrical conductivity and some physical properties were investigated. We observed the nanofibers’ shape, increasing electrical conductivity, thermal resistance and a higher molecular weight with the synthesized polycarbazole under an electric field compared to the polymer synthesized in the same conditions in the absence of an electric field. First, we chemically synthesized polycarbazole at different times. Additionally, to find the optimizing conditions, we changed certain parameters, such as the ratio of the obtained molar of initiator to monomer, the oxidant, initiator and solvent, separately, and compared the obtained results. Then, we repeated this reaction in the best conditions and under different electric fields in constant time, allowing us to characterize the shape, mass and conductivity. Next, the polymerization was carried out at the best electric field in different times. Finally, the best time and amount of electric field for polymerization were determined. The electrical conductivity of polycarbazoles was studied with the four-probe method. The conductivity of the films oxidized using FeCl₃ (dry) and protonated with p-toluenesulfonic acid (PTSA) at 3 h was higher than 8.9 × 10⁻⁴ S/cm under a 12 KV/m electric field. Additionally, the results showed an enhanced thermal resistance to ageing. Full article

Three-dimensional (3D) printing has gained increasing attention for its unique ability to create geometrically complex designs, which not only can be used for mass manufacturing but also has environmental and economic benefits. Additionally, as far as the food industry is concerned, this emerging technology has the potential to personalize products in terms of shape and/or nutritional requirements creating a wide range of food items with specially made shapes, colors, textures, tastes, and even nutrition using suitable raw materials/food components. In the future, 3D food printing could make complex food models with special interior design. This review gives attention to intelligent food packaging. Point-of-use machinery for manufacturing smart packaging, with a 3D printing approach, enables the use of multifunctional smart components and is self-identifying and highly sensitive, while using biocompatible non-toxic materials is cheaper than traditional manufacturing methods. This would create smart food packaging and in turn prevent customers from purchasing unsuitable food and thus reduce food waste. Future studies can make the process more compatible and efficient with a wide variety of materials that could be used to improve the 3D printing process. Full article

Different methods which could be used to produce colloidal dispersions of polyaniline (PANI) nano-objects without templates are described. While the methods are non-deterministic, different nano-objects (nanospheres, nanofibers, nanobelts, nanorice, nanotubes, nanorods, nanodisks, etc.) can be produced. Those most used are: (i) solution polymerization with steric stabilizers (SPS) to produce nanospheres, (ii) interfacial polymerization (IP) to produce nanofibers and (iii) solution polymerization in the presence of additives (SPA) to produce nanotubes. Oxidation of aniline in aqueous solution could produce nanotubes, nanofibers and other shapes by controlling mass transport/concentration of reactants, pH, and the presence of oligomers/additives. The different models proposed to explain the formation of various nano-objects are discussed. Mechanochemical polymerization (MCP) could produce nanofibers or nanospheres by controlling the aniline/oxidant ratio. PANI nanospheres of tunable sizes can also be produced by nanoprecipitation (NPT) of preformed PANI from its solutions using an antisolvent. The geometrical constraints to the small nano-objects made of high-molecular-weight rigid polymers are described. The conditions to produce nanostructures also affect the intrinsic properties of PANI (conductivity, crystallinity, and electroactivity). Selected technological applications of PANI nano-objects manufactured as colloidal dispersions without templates are discussed. Based on the reviewed work and models, future lines of work are proposed. Full article

This article fundamentally reviews progress in the design and manufacturing of three-dimensional (3D) graphene-based nanocomposites for technical applications. The 3D graphene nanostructures have been manufactured using techniques like the template method, chemical vapor deposition, sol-gel, freeze-drying, hydrothermal technique, and other approaches. The nanofoam has been reinforced in polymers to achieve superior structural, morphological, and physical characteristics of the ensuing polymer/graphene nanofoam nanocomposites. The polymer/graphene nanofoam nanocomposites have been manufactured using the approaches like direct template method, in situ technique, infiltration process, and other methods. The 3D nanofoam- and polymer-based nanostructures have shown high specific surface area, suppleness, electron transport, thermal conduction, mechanical resilience, and other physical properties. The technical applications of hierarchical graphene nanofoams have been observed in the fields of radiation shielding, solar cells, supercapacitors, fuel cells, and other applications. Full article

In order to study the relationship between the rheology of a surfactant’s concentrated dispersions and the oil and water liquid crystals from which O/W nanoemulsions (NEs) can be produced by water dilution, the phase diagram of a model SOW (surfactant–oil–water) system was constructed. The dispersion’s compositions to be characterized by rheology were chosen in the diagram’s regions that contain liquid crystal phases. For this, the dilution lines S/O = 25/75, 55/45, and 70/30 with a water content of 20 and 40 wt% (corresponding to surfactant concentrations between 15 and 55 wt%) were chosen. By adding these dispersions to a water pool, NEs were obtained, and it was shown that droplet size distribution depends on the amount of the liquid crystal phase in the initial dispersion and its rheology. The study of the oscillatory amplitude of the dispersion showed a linear viscoelastic plateau (G’ > G”) and a softening deformation region (G” > G’), indicating a viscoelastic behavior of the dispersions. The study was carried out at a constant temperature of 30 °C, and the results show that rheological characterization by itself is not enough to predict that monomodal droplet distributions are obtained. However, the presence and quantity of lamellar liquid crystal phase are important to obtain monodisperse and kinetically stable NEs. Full article

This review article highlights essential manufacturing strategies for the formation of graphene reinforced polymeric nanocomposites. For graphene reinforced thermoplastic, thermosetting and conducting matrix nanomaterials have been manufactured using solution casting, melt blending, in situ polymerization, electrospinning, 3D printing, and several other techniques. Solution processing has been well thought-out as an advantageous technique, relative to melt mixing, in terms of graphene dispersion in polymeric matrices. An in situ polymerization process has also been considered valuable to form homogeneously dispersed polymer/graphene nanocomposites having superior physical characteristics. Nevertheless, the manufacturing techniques for polymer/graphene nanocomposites have relative advantages and disadvantages to be considered for graphene-based nanocomposites. Moreover, numerous challenges need to be overcome to optimize the processing parameters for the fabrication of high-performance polymer/graphene nanocomposites. Full article

3D printing is a promising technology for creating polymer objects of a given architecture with specified functional properties. In fact, the choice of filaments for 3D printing is quite limited. Here, we report a process for producing polystyrene filaments with 0.0025–2 wt.% single-walled carbon nanotubes (SWCNTs) by extruding crushed polystyrene composites. The resulting filaments are characterized by a high uniformity of filler distribution and the absence of air pores. Comparison of microscopy data and electromagnetic properties of base composites and composite materials printed from filaments showed that extrusion and printing improve SWCNT dispersion. The proposed method can be used to create filaments for 3D printing of objects from various base polymers containing functional fillers up to the electrical percolation threshold and above. Full article

Nanomaterials (NMs) that are created with zinc oxide are very valuable for a wide variety of applications. There is a present interest in ZnO nanoparticles in a wide range of industries. This interest may be attributed to the fact that ZnO NPs have many important features. It will be necessary for ZnO NPs to possess certain qualities in order for them to rapidly find uses in industry and for these applications to have an effect on the expansion of the economy. A large surface area, a large bandgap, photocatalytic property, biosensing, bioimaging, and other qualities are included in this list. In this article, the extraordinary characteristics of ZnO NPs, as well as their novel applications in industrial settings and the challenges that come along with their utilization, will be discussed. Full article

Direct laser interference patterning (DLIP) involves the formation of patterns of light intensity using coherent laser light beams that interfere between them. Light on the ultraviolet (<350 nm) and NIR (800–2000 nm) is absorbed in chromophores present in the polymer structure or in loaded absorbing species (dyes, polymers, nanoparticles). The absorbed light induces photothermal/photochemical processes, which alter permanently the topography of the polymer surface. The success of DLIP at different wavelengths is discussed in relation to the optical/thermal properties of the polymers and previous data on laser ablation of polymers. The size of the pattern is related directly to the wavelength of the light and inversely to the sine of the angle between beams and the refractive index of the external medium. In that way, nanometric structures (<100 nm) could be produced. Since the patterning occurs in a single short pulse (<10 ns), large surfaces can be modified. Both bacterial biofilm inhibition and human cell differentiation/orientation have been achieved. Large improvements in technological devices (e.g., thin film solar cells) using DLIP structured surfaces have also been demonstrated. Prospective application of DLIP to common polymers (e.g., Teflon^®) and complex polymeric systems (e.g., layer-by-layer multilayers) is discussed on the basis of reported polymer data. Full article

Beam splitters are widely used in various optical systems, but traditional beam splitters are bulky and heavy, which are not conducive to the integrated utilization of optical devices. Metamaterials have attracted extensive attention as a kind of miniature artificial materials, and there have been many works on the design of metasurface beam splitters. Using metasurfaces, multiple functions of traditional beam splitters can be achieved. Meanwhile, metasurface beam splitters have the advantages of small size, easy integration, flexible design of beam-splitting performance, and tunable functions. This review surveys the current work on metasurface beam splitters and provides a classification and introduction to metasurface beam splitters. Metasurface beam splitters are expected to play a huge role in interferometers, multiplexing, multi-beam communications, and more. Full article

A method to conformally coat silica nanosprings with magnesium via sublimation at 450 °C has been developed. In addition, Mg thin films were grown on Si(100) using this method to determine the effects of substrate morphology (nanoscale curvatures vs. planar) on the interfacial morphology of the Mg coating. High-resolution/powder X-ray diffraction (HRXRD/PXRD) on both the Mg-coated NS and the thin film revealed the presence of Mgand MgO due to exposure of the samples to air. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) confirmed the presence of Mg on the nanosprings. Elemental mapping with TEM-EDS verified that Mg uniformity and conformally coats the nanosprings. Nanocrystallinity of the Mg coating on the nanosprings was determined to be polycrystalline by TEM and selected area electron diffraction (SAED). In contrast, the process produces large micron-scale crystals on planar surfaces. Full article