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Topic Review
Chitosan Nanocomposite Coatings
Functional nanocomposites with biopolymers and zinc oxide (ZnO) nanoparticles is an emerging application of photocatalysis in antifouling coatings. The reduced chemical stability of ZnO photocatalyst in the acidic media in which chitosan is soluble affects the performance of chitosan nanocomposites in antifouling applications. In this study, a thin shell of amorphous tin oxide (SnOx) was grown on the surface of ZnO to form ZnO–SnOx core–shell nanoparticles that improved the chemical stability of the photocatalyst, as examined at pH 3 and 6. The photocatalytic activity of ZnO–SnOx in the degradation of methylene blue (MB) dye under visible light showed a higher efficiency than that of ZnO nanoparticles due to improved electron-hole separation. Meanwhile, the incorporation of photocatalysts into the chitosan matrix enhanced the thermal stability of the coatings. Chitosan-based antifouling coatings with varying percentages of ZnO or ZnO–SnOx nanoparticles, with or without the glutaraldehyde (GA) crosslinking of chitosan, were developed and studied for the prevention of biofouling. 
  • 975
  • 19 May 2021
Topic Review
Nanoimprint Lithography
Optical spectrometers and sensors have gained enormous importance in metrology and information technology, frequently involving the question of size, resolution, sensitivity, spectral range, efficiency, reliability, and cost. Nanomaterials and nanotechnological fabrication technologies have huge potential to enable an optimization between these demands, which in some cases are counteracting each other. This paper focuses on the visible and near infrared spectral range and on five types of optical sensors (optical spectrometers): classical grating-based miniaturized spectrometers, arrayed waveguide grating devices, static Fabry–Pérot (FP) filter arrays on sensor arrays, tunable microelectromechanical systems (MEMS) FP filter arrays, and MEMS tunable photonic crystal filters. The comparison between this selection of concepts concentrates on (i) linewidth and resolution, (ii) required space for a selected spectral range, (iii) efficiency in using available light, and (iv) potential of nanoimprint for cost reduction and yield increase. 
  • 974
  • 16 Mar 2021
Topic Review
Gas Sensors Based on Single-Wall Carbon Nanotubes
Single-wall carbon nanotubes (SWCNTs) have a high aspect ratio, large surface area, good stability and unique metallic or semiconducting electrical conductivity, they are therefore considered a promising candidate for the fabrication of flexible gas sensors that are expected to be used in the Internet of Things and various portable and wearable electronics. 
  • 974
  • 31 Aug 2022
Topic Review
Plasmonic Nanosensors
Current advances in the fabrication of smart nanomaterials and nanostructured surfaces find wide usage in the biomedical field. Nanosensors based on localized surface plasmon resonance exhibit unprecedented optical features that can be exploited to reduce the costs, analytic times, and need for expensive lab equipment. Moreover, they are promising for the design of nanoplatforms with multiple functionalities (e.g., multiplexed detection) with large integration within microelectronics and microfluidics.
  • 973
  • 26 Apr 2022
Topic Review
Enhanced Performance of Lithium-Ion Batteries
Lithium-ion batteries (LIBs) have been used in portable electric devices and electric vehicles (EVs) for years due to their high energy and power densities, satisfactory cycle life and the affordable materials and manufacturing costs. To meet the growing market demand for cheaper and more efficient energy storage technologies for EVs and power grids, higher energy storage density and efficiency, and a longer cycle life should be achieved in the next generation of LIBs. Silicon (Si) is considered as one of the most promising candidates for next generation negative electrode (negatrode) materials in LIBs due to its much higher theoretical specific charge capacity than the current commercial negatrode (carbon-based).
  • 971
  • 25 Apr 2022
Topic Review
ZnO Nanowires Cold Cathode
A cold cathode has many applications in high frequency and high power electronic devices, X-ray source, vacuum microelectronic devices and vacuum nanoelectronic devices. After decades of exploration on the cold cathode materials, ZnO nanowire has been regarded as one of the most promising candidates, in particular for large area field emitter arrays (FEAs). Numerous works on the fundamental field emission properties of ZnO nanowire, as well as demonstrations of varieties of large area vacuum microelectronic applications, have been reported. Moreover, techniques such as modifying the geometrical structure, surface decoration and element doping were also proposed for optimizing the field emissions.
  • 967
  • 06 Sep 2021
Topic Review
Nanosystems Applied to HIV Infection
This review highlights the advantages to use nanosized structures for the prevention and treatments of  HIV infection. We briefly  evaluate the most recent developments associated with different polymeric nanosystems.
  • 966
  • 08 Feb 2021
Topic Review
Nanocarriers for Sustainable Active Packaging
Lockdown has been installed due to the fast spread of COVID-19, and several challenges have occurred. Active packaging was considered a sustainable option for mitigating risks to food systems during COVID-19. Biopolymeric-based active packaging incorporating the release of active compounds with antimicrobial and antioxidant activity represents an innovative solution for increasing shelf life and maintaining food quality during transportation from producers to consumers. However, food packaging requires certain physical, chemical, and mechanical performances, which biopolymers such as proteins, polysaccharides, and lipids have not satisfied. In addition, active compounds have low stability and can easily burst when added directly into biopolymeric materials. Due to these drawbacks, encapsulation into lipid-based, polymeric-based, and nanoclay-based nanocarriers has currently captured increased interest. Nanocarriers can protect and control the release of active compounds and can enhance the performance of biopolymeric matrices. 
  • 966
  • 26 Jan 2022
Topic Review
Bimodal Nanostructure
Nanocrystalline metals developed based on fine grain strengthening always have excellent strength, but are accompanied by a drop in ductility. Substantial efforts have been dedicated to design new microstructures and develop the corresponding processing technologies in order to solve this problem. One of the novel nanostructures is the bimodal grain size distribution nanostructure.
  • 965
  • 08 Oct 2022
Topic Review
Thermal Conductivity Techniques
Conventional thermal fluids have found limited application owing to low thermal conductivity (TC). The need for more efficient fluids has become apparent leading to the development of nanofluids as advanced thermal fluids. Nanofluid synthesis by suspending nano-size materials into conventional thermal fluids to improve thermal properties has been extensively studied. TC is a pivotal property to the utilization of nanofluids in various applications as it is strongly related to improved efficiency and thermal performance. Numerous studies have been conducted on the TC of nanofluids using diverse nanoparticles and base fluids. 
  • 962
  • 10 Feb 2023
Topic Review
CNT-Based Analytical Biosensing Platforms in Viruses Detection
It has been proven that viral infections pose a serious hazard to humans and also affect social health, including morbidity and mental suffering, as illustrated by the COVID-19 pandemic. The early detection and isolation of virally infected people are, thus, required to control the spread of viruses. Due to the outstanding and unparalleled properties of nanomaterials, numerous biosensors were developed for the early detection of viral diseases via sensitive, minimally invasive, and simple procedures. To that aim, viral detection technologies based on carbon nanotubes (CNTs) are being developed as viable alternatives to existing diagnostic approaches. 
  • 957
  • 13 Dec 2022
Topic Review
Porphyrin and Zn-Phtalocyanine as Optical-Sensor
In the detection of molecular species, optical sensing methods are very attractive. Planar Optical Waveguide (POWG) sensor represents an interesting system that consists of a waveguide layer, that usually is a potassium-ion-exchange glass substrate, and a sensor layer; the response of this sensor depends on the evanescent wave principle of laser light. The detection of the molecule is based on two important factors: the absorbance of the film, that is affected by the interaction with the analyte molecules and the change of the reflected light intensity from the POWG thin film that is related to the absorbance changes.
  • 952
  • 30 Jun 2021
Topic Review
Electrospun Nanofibrous Membrane
In biotechnology, the field of cell cultivation is highly relevant. Cultivated cells can be used, for example, for the development of biopharmaceuticals and in tissue engineering. Commonly, mammalian cells are grown in bioreactors, T-flasks, well plates, etc., without a specific substrate. Nanofibrous mats, however, have been reported to promote cell growth, adhesion, and proliferation. Here, we give an overview of the different attempts at cultivating mammalian cells on electrospun nanofiber mats for biotechnological and biomedical purposes. Starting with a brief overview of the different electrospinning methods, resulting in random or defined fiber orientations in the nanofiber mats, we describe the typical materials used in cell growth applications in biotechnology and tissue engineering. The influence of using different surface morphologies and polymers or polymer blends on the possible application of such nanofiber mats for tissue engineering and other biotechnological applications is discussed. Polymer blends, in particular, can often be used to reach the required combination of mechanical and biological properties, making such nanofiber mats highly suitable for tissue engineering and other biotechnological or biomedical cell growth applications.
  • 948
  • 19 Aug 2021
Topic Review
Organic Sensitizers for Indoor DSSC Applications
Among the emerging photovoltaic (PV) technologies, Dye-Sensitized Solar Cells (DSSCs) appear especially interesting in view of their potential for unconventional PV applications. In particular, DSSCs have been proven to provide excellent performances under indoor illumination, opening the way to their use in the field of low-power devices, such as wearable electronics and wireless sensor networks, including those relevant for application to the rapidly growing Internet of Things technology. Considering the low intensity of indoor light sources, efficient light capture constitutes a pivotal factor in optimizing cell efficiency. Consequently, the development of novel dyes exhibiting intense absorption within the visible range and light-harvesting properties well-matched with the emission spectra of the various light sources becomes indispensable.
  • 947
  • 06 Dec 2023
Topic Review
Photoactive Heterostructures
In this study we consider the results on the development and exploration of heterostructured photoactive materials with major attention focused on what are the better ways to form this type of materials and how to explore them correctly. Regardless of what type of heterostructure, metal–semiconductor or semiconductor–semiconductor, is formed, its functionality strongly depends on the quality of heterojunction. In turn, it depends on the selection of the heterostructure components (their chemical and physical properties) and on the proper choice of the synthesis method. Several examples of the different approaches such as in situ and ex situ, bottom-up and top-down, are reviewed. At the same time, even if the synthesis of heterostructured photoactive materials seems to be successful, strong experimental physical evidence demonstrating true heterojunction formation are required. A possibility for obtaining such evidence using different physical techniques is discussed.
  • 945
  • 24 Mar 2021
Topic Review
Applications of Electrospun Nanofibers in Catalysis
Electrospinning has become a very popular technique for the fabrication of nanofibers due to its low cost and simple handling. Nanofiber materials have found utilization in many areas such as medicine, sensors, batteries, etc. In catalysis, these materials also present important advantages, since they present a low resistance to internal diffusion and a high surface area to volume ratio. These advantages are mainly due to the diameter–length proportion. A bibliographic analysis on the applications of electrospun nanofibers in catalysis shows that there are two important groups of catalysts that are being investigated, based on TiO2 and in carbon materials. The main applications found are in photo- and in electro-catalysis. 
  • 945
  • 07 Feb 2022
Topic Review
Wearable Nano-Based Gas Sensors for Environmental Monitoring
With a rising emphasis on public safety and quality of life, there is an urgent need to ensure optimal air quality, both indoors and outdoors. Detecting toxic gaseous compounds plays a pivotal role in shaping our sustainable future.
  • 944
  • 03 Nov 2023
Topic Review
Nanomaterials Based on Cashew Nut Shell Liquid
Cashew nut shell liquid (CNSL), obtained as a byproduct of the cashew industry, represents an important natural source of phenolic compounds, with important environmental benefits due to the large availability and low cost of the unique renewable starting material, that can be used as an alternative to synthetic substances in many industrial applications. The peculiarity of the functional groups of CNSL components, such as phenolic hydroxyl, the aromatic ring, acid functionality, and unsaturation(s) in the C15 alkyl side chain, permitted the design of interesting nanostructures. Cardanol (CA), anacardic acid (AA), and cardol (CD), opportunely isolated from CNSL, served as building blocks for generating an amazing class of nanomaterials with chemical, physical, and morphological properties that can be tuned in view of their applications, particularly focused on their bioactive properties.
  • 943
  • 19 Sep 2023
Topic Review
Tailoring Nanoadsorbent Surfaces for Recycling of LTM
A series of adsorbents were tailored for selective extraction of rare earth elements (REE) and late transition metals (LTM) via grafting of ligands bearing specific N- and S-donor functions. All obtained adsorbents showed relatively quick uptake kinetics and high adsorption capacity 0.5 to 1.8 mmol/g, depending on the function and the target metal ion. The adsorption equilibrium data analyzed and fitted well to Langmuir isotherm model revealing monolayer adsorption process on homogeneously functionalized silica nanoparticles (NPs). Most of the employed ligands demonstrated higher affinity towards LTM compared to REE, related to the nature of the functional groups and their arrangement on the surface of nanoadsorbent.
  • 942
  • 11 Apr 2022
Topic Review
Effects of Micro-/Nanorobots on Various Microbial Species
One of the most pressing concerns to global public health is the emergence of drug-resistant pathogenic microorganisms due to increased unconscious antibiotic usage. With the rising antibiotic resistance, existing antimicrobial agents lose their effectiveness over time. This indicates that newer and more effective antimicrobial agents and methods should be investigated. 
  • 940
  • 23 Aug 2022
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