Recent Advances in the Methods for Designing Superhydrophobic Surfaces

The investigations of superhydrophobicity and self-cleaning surfaces have been given a lot of attention in the last few decades. The surfaces having water contact angle larger than 90° are termed as hydrophobic surfaces and those which exhibit contact angle higher than 150° are said to be superhydrophobic. Such surfaces were first observed in nature in various plants and animals, for example, lotus leaf-like structures. Water repellence of various materials have shown great influences on various applications such as self-cleaning, anti-ageing, water-oil separation, water corrosion in electrical industry, water proof textiles, controlled transportation of fluids, etc. Generally, surface micro/nanostructuring combined with low surface energy of materials leads to extreme anti-wetting properties. The hundreds of research articles and more than 450 patents on the subject of nature mimicking self-cleaning surfaces prove the potential of this topic

Plasma jet based <i>in situ</i> reduction of copper oxide in direct write printing

Printing of nanostructured films with tailored oxidation state and electronic structure can have far reaching applications in several areas including printable electronics, optoelectronics, solar cells, catalytic conversion, and others. Widely used inkjet/aerosol/screen printing techniques require pre- and postprocessing for enhanced adhesion and tailoring of the chemical state of the thin film. Herein, we demonstrate atmospheric pressure plasma jet printing with unique capability to print and tune in situ the electronic properties and surface morphology of nanomaterials. Plasma printing of copper thin films with tailored oxidation state from an inexpensive copper oxide precursor is demonstrated and characterized using x-ray absorption spectroscopy, Raman spectroscopy, and electrical measurements

Temperature influence on the diethylamine sensing abilities of CuO nanoparticles deposited by atmospheric pressure plasma

In this work we present a copper oxide nanostructured analysed as a gas sensor but the focus of the paper is on the temperature dependance of the sensor sensing properties. As a case study temperature dependent diethylamine sensing is presented.The CuO nano flakes were deposited and evenly distributed on intercalated electrodes by an atmospheric pressure plasma source. The sensor was electrically connected to ohmmetre and inserted in an oven chamber where it was isolated from atmosphere and heated to desired tempearuteres. The intrinsic resistnace of the sensor was measured in dependence of the temperature and the temperature change rate. Then the possibility to detect diethylamine was investigated and the sensor response studied. Finally, the temperature dependence of the detection of the amine was explored. It was possible to demonstrate reliable sensing of the amine down to temperatures of 100 °C and below

Single-layer and double-layer filtration materials based on polyvinylidene fluoride-co-hexafluoropropylene nanofibers coated on melamine microfibers

In this work, we demonstrate selected optimization changes in the simple design of filtration masks to increase particle removal efficiency (PRE) and filter quality factor by combining experiments and numerical modeling. In particular, we focus on single-layer filters fabricated from uniform thickness fibers and double-layer filters consisting of a layer of highly permeable thick fibers as a support and a thin layer of filtering electrospun nanofibers. For single-layer filters, we demonstrate performance improvement in terms of the quality factor by optimizing the geometry of the composition. We show significantly better PRE performance for filters composed of micrometer-sized fibers covered by a thin layer of electrospun nanofibers. This work is motivated and carried out in collaboration with a targeted industrial development of selected melamine-based filter nano- and micromaterials

Effective Fungal Spore Inactivation with an Environmentally Friendly Approach Based on Atmospheric Pressure Air Plasma.

Fungal contamination of surfaces is a global burden, posing a major environmental and public health challenge. A wide variety of antifungal chemical agents are available; however, the side effects of the use of these disinfectants often result in the generation of toxic residues raising major environmental concerns. Herein, atmospheric pressure air plasma generated by a surface barrier discharge (SBD) is presented as an innovative green chemical method for fungal inactivation, with the potential to become an effective replacement for conventional chemical disinfection agents, such as Virkon. Using Aspergillus flavus spores as a target organism, a comparison of plasma based decontamination techniques is reported, highlighting their respective efficiencies and uncovering their underpining inactivation pathways. Tests were performed using both direct gaseous plasma treatment and an indirect treatment using a plasma activated aqueous broth solution (PAB). Concentrations of gaseous ozone and nitrogen oxides were determined with Fourier-transform infrared spectroscopy (FTIR) and Optical emission spectroscopy (OES), whereas hydrogen peroxides, nitrites, nitrates, and pH were measured in PAB. It is demonstrated that direct exposure to the gaseous plasma effluent exhibited superior decontamination efficiency and eliminated spores more effectively than Virkon, a finding attributed to the production of a wide variety of reactive oxygen and nitrogen species within the plasma

Programmable de novo designed coiled coil-mediated phase separation in mammalian cells

Abstract Membraneless liquid compartments based on phase-separating biopolymers have been observed in diverse cell types and attributed to weak multivalent interactions predominantly based on intrinsically disordered domains. The design of liquid-liquid phase separated (LLPS) condensates based on de novo designed tunable modules that interact in a well-understood, controllable manner could improve our understanding of this phenomenon and enable the introduction of new features. Here we report the construction of CC-LLPS in mammalian cells, based on designed coiled-coil (CC) dimer-forming modules, where the stability of CC pairs, their number, linkers, and sequential arrangement govern the transition between diffuse, liquid and immobile condensates and are corroborated by coarse-grained molecular simulations. Through modular design, we achieve multiple coexisting condensates, chemical regulation of LLPS, condensate fusion, formation from either one or two polypeptide components or LLPS regulation by a third polypeptide chain. These findings provide further insights into the principles underlying LLPS formation and a design platform for controlling biological processes

Oriented Carbon Nanostructures by Plasma Processing: Recent Advances and Future Challenges

Carbon, one of the most abundant materials, is very attractive for many applications because it exists in a variety of forms based on dimensions, such as zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and-three dimensional (3D). Carbon nanowall (CNW) is a vertically-oriented 2D form of a graphene-like structure with open boundaries, sharp edges, nonstacking morphology, large interlayer spacing, and a huge surface area. Plasma-enhanced chemical vapor deposition (PECVD) is widely used for the large-scale synthesis and functionalization of carbon nanowalls (CNWs) with different types of plasma activation. Plasma-enhanced techniques open up possibilities to improve the structure and morphology of CNWs by controlling the plasma discharge parameters. Plasma-assisted surface treatment on CNWs improves their stability against structural degradation and surface chemistry with enhanced electrical and chemical properties. These advantages broaden the applications of CNWs in electrochemical energy storage devices, catalysis, and electronic devices and sensing devices to extremely thin black body coatings. However, the controlled growth of CNWs for specific applications remains a challenge. In these aspects, this review discusses the growth of CNWs using different plasma activation, the influence of various plasma-discharge parameters, and plasma-assisted surface treatment techniques for tailoring the properties of CNWs. The challenges and possibilities of CNW-related research are also discussed

Green Procedure to Manufacture Nanoparticle-Decorated Paper Substrates

For this study, a paper impregnated with silver nanoparticles (AgNPs) was prepared. To prepare the substrates, aqueous suspensions of pulp fines, a side product from the paper production, were mixed with AgNP suspensions. The nanoparticle (NP) synthesis was then carried out via laser ablation of pure Ag in water. After the sheet formation process, the leaching of the AgNPs was determined to be low while the sheets exhibited antimicrobial activity toward Escherichia coli (E. coli)

High sensitivity of a carbon nanowall-based sensor for detection of organic vapours

The high sensitivity in response, selectivity and reversibility was achieved on a carbon nanowall-based sensor for the vapor detection of volatile organic compounds, which were tested by an electrical resistance method during adsorption and desorption cycles. The maze-like structure of two different carbon nanowalls with wall-to-wall distances of 100 nm and 300 nm were prepared on a silicone substrate by a plasma-enhanced chemical vapor deposition system while varying processing parameters. Four organic vapors: iso-pentane; diethyl ether; acetone; and methanol; were selected in order to evaluate the relationship between the change in resistance, molecular weight of the adsorbent and the polarity. The results show that the carbon nanowalls with average wall distance 100 nm exhibit substantially enhanced electrical response to all volatile organic compound vapors used in comparison with the nanowalls with 300 nm wall distance as well as entangled multiwall carbon nanotube networks. This journal is © The Royal Society of Chemistry.Bi-JAP-2015-2017-3, ARRS, Javna Agencija za Raziskovalno Dejavnost RS; L2-6769, ARRS, Javna Agencija za Raziskovalno Dejavnost RS; JSPS, Javna Agencija za Raziskovalno Dejavnost RS; 25600123, JSPS, Javna Agencija za Raziskovalno Dejavnost RSMinistry of Education, Youth and Sports of the Czech Republic - Program NPU I [LO1504]; Institute of Hydrodynamics [AV0Z20600510]; Slovenian Research Agency (ARRS) [L2-6769, Bi-JAP-2015-2017-3]; JSPS [25600123