Preparation and Characterization of a Novel Poly(vinylidene fluoride-co-hexafluoropropylene)/Poly(ethersulfone) Blend Membrane Fabricated Using an Innovative Method of Mixing Electrospinning and Phase Inversion

In this work, a novel polymeric membrane was innovated in terms of composition and preparation techniques. A blend of poly(vinylidene fluoride-co-hexafluoropropylene) (PcH) and poly(ethersulfone) (PES) (18 wt.% total polymer concentration) was prepared using a N-methylpyrrolidone (NMP) and N, N-Dimethylformamide (DMF) solvents mixture, while Lithium chloride (0.05–0.5 wt.%) was used as an additive. The electrospinning and phase inversion techniques were used together to obtain a novel membrane structure. The prepared membranes were characterized using scanning electron microscope imaging, energy dispersive X-Ray, differential scanning calorimeter, thermogravimetric analysis, and Fourier transfer infrared spectroscopy-attenuated total reflectance analyses. Moreover, the static water contact angle, membrane thickness, porosity, surface roughness as well as water vapor permeability were determined. ImageJ software was used to estimate the average fiber diameter. Additionally, the effect of the change of PcH concentration and coagulation bath temperature on the properties of the fabricated membrane was studied. The novel developed membrane has shown a good efficiency in terms of properties and features, as a membrane suitable for membrane distillation (MD); a high porosity (84.4% ± 0.6), hydrophobic surface (136.39° ± 3.1 static water contact angle), and a water vapor permeability of around 4.37 × 10−5 g·m/m2·day·Pa were obtained. The prepared membrane can be compared to the MD membranes commercially available in terms of properties and economic value.

Numerical Investigation of Fabricated MWCNTs/Polystyrene Nanofibrous Membrane for DCMD

The effect of compositing multiwalled carbon nanotubes (MWCNTs) with polystyrene (PS) to fabricate nanofibrous membrane by electrospinning technique and comparing the direct contact membrane distillation (DCMD) performance of the blank and composite membranes is evaluated numerically. Surface morphology of both the pristine and the composite membrane was studied by SEM imaging while the average fiber diameter and average pore size were measured using ImageJ software. Static water contact angle and porosities were also determined for both membranes. Results showed significant enhancement in both the hydrophobicity and porosity of the composite membrane by increasing the static water contact angle from 145.4° for the pristine PS membrane to 155° for the PS/MWCNTs composite membrane while the porosity was increased by 28%. Simulation results showed that at any given feed inlet temperature, the PS/MWCNTs membrane have higher permeate flux and better overall system performance.

Surface treated cotton fabric with stain repellent property for the use in aircraft upholstery

Nanotechnology modifications play a major role in textile industry due to extraordinary properties exhibit in fabrics due to nanomaterials. It offers different functionalities namely self-cleaning, wrinkle resistance, flame retardancy, protection from UV radiations or antibacterial property. Further, it is important to maintain cleanliness in aircraft upholstery always but the airliners have to bear a considerable amount of money to clean up the aircraft upholstery. Interestingly, nanotechnology can provide stain repellence property for fabrics in aircraft upholstery. This study covers a method of developing a stain repellent fabric which was stable even after 25 standard laundering conditions. In this study nanotechnology was used to modify a cotton fabric with stain repellant property. After nanotechnology modification, the surface wettability of the treated fabrics was characterized by static water contact angle measurements before and after 25 washes carried out under standard laundering conditions. Similar testings were carried out for the untreated fabric samples. The static water contact angle for the treated fabric was 161° with the recovery of 97.5% after 25 washing cycles. SEM and AFM micrographs were used to analyze the coatings. Further, the stability of hydrophobicity in the modified cotton fabric after 25 washes was also tested for tea, coffee, and water solutions which are vulnerable stain types in aircraft upholstery. It clearly proved that the modified cotton fabric even after 25 washes showed hydrophobicity for tea, coffee, and water. Therefore, it could be concluded that the developed modified cotton fabric can consider to be used as an aircraft upholstery.

Development of Superhydrophobic Polyester (Polyethylene terephthalate) Fabric for Multiple Applications

This study intended to develop a healthy and environmentally friendly super-hydrophobic PET polyester textile fabric using a specific Fluoro Silane finish (SHF). A novel SHF was prepared and applied on a polyester fabric using a pad-dry-cure method. The finished fabric was evaluated for the degree of hydrophobicity, durability and stain repellence. The finished fabric exhibited static water contact angle greater than 170o and received 90 AATCC (4 ISO) rating that is recognized as super-hydrophobicity and this property was maintained even after a 50,000-cycle abrasion test. FTIR analysis identified the characteristic peaks related to Si-O-Si and C-F asymmetric stretching bands of the finish on the fabric indicating a robust attachment on the fabric. Finished fabric did not show any change in appearance or tactile characteristics of the fabric.

Hydrophobic Zinc Oxide Nanocomposites for Consolidation and Protection of Quartzite Sculptures: A Case Study

Quartzite sculptures are considered some of the most impressive and informative archaeological remains which have been found in the most of Egyptian archaeological sites. Regrettably, quartzite sculptures suffer from many deterioration aspects such as granular disintegration, scaling, cracking, efflorescence, soiling, microbiological colonization. Water is the main aggressive deterioration factor of stones and stone-based monuments, as in addition to its direct role in deterioration mechanisms, it plays as a catalyst in the physicochemical and microbiological deterioration processes.During the last two decades, polymer nanocomposites have widely been applied in the field of cultural heritage conservation due to their unique physical and chemical characteristics. Zinc oxide nanoparticles are among the most important semiconductive nanomaterials that have been applied in the fabrication of nanocomposites. They have been demonstrated to improve the physicochemical and mechanical properties of polymers. In addition, zinc oxide nanoparticles were mixed with polymers in order to fabricate superhydrophobic and self-cleaning protective materials.The aim of this paper is to evaluate the efficiency of zinc oxide nanocomposites, in order to select the best of them for the consolidation and protection of a colossal quartzite statue of Ramesses II. The properties of the treated quartzite samples were comparatively examined by colourimetric measurements, static water contact angle, compressive strength, and scanning electron microscope.

Bio-Based Coatings for Food Metal Packaging Inspired in Biopolyester Plant Cutin

Metals used for food canning such as aluminum (Al), chromium-coated tin-free steel (TFS) and electrochemically tin-plated steel (ETP) were coated with a 2–3-µm-thick layer of polyaleuritate, the polyester resulting from the self-esterification of naturally-occurring 9,10,16-trihydroxyhexadecanoic (aleuritic) acid. The kinetic of the esterification was studied by FTIR spectroscopy; additionally, the catalytic activity of the surface layer of chromium oxide on TFS and, in particular, of tin oxide on ETP, was established. The texture, gloss and wettability of coatings were characterized by AFM, UV-Vis total reflectance and static water contact angle (WCA) measurements. The resistance of the coatings to solvents was also determined and related to the fraction of unreacted polyhydroxyacid. The occurrence of an oxidative diol cleavage reaction upon preparation in air induced a structural modification of the polyaleuritate layer and conferred upon it thermal stability and resistance to solvents. The promoting effect of the tin oxide layer in such an oxidative cleavage process fosters the potential of this methodology for the design of effective long-chain polyhydroxyester coatings on ETP.

Superhydrophobic Surface with Gamma Irradiation Resistance and Self-Cleaning Effect in Air and Oil

A superhydrophobic surface was synthesized by a combination of an epoxy/polymethylphenylsiloxane matrix and dual-scale morphology of silica (SiO2) nanoparticles. When the amount of SiO2 reached 30 wt.%, the as-prepared surface showed a high static water contact angle (WCA) of 154° and a low sliding angle (SA) of 5°, excellent water repellency, and dirt-removal effects both in air and oil (hexamethylene). Even after exposure to as high as a 12.30 Mrad dose of gamma-rays, the composite surface still maintained its superior performance.

Nanomaterials for Consolidation and Protection of Egyptian Faience Form Matteria, Egypt

Egyptian faience is one of the most important archaeological materials that contain a lot of historical and technical information about ancient Egyptian civilization. Unfortunately, the Egyptian faience objects subject to many deterioration factors, especially humidity. Water has a direct role in dissolving the soluble components, it accelerates the physiochemical deterioration processes. In the present study, four types of ready to use nanoproducts were evaluated. It was done to select the best of them to consolidate and protect some archaeological faience from Matteria magazine. The properties of the treated samples, were comparatively investigated by colormetric measurements, static water contact angle, total immersion water absorption, compressive strength, and scanning electron microscope.

Adhesion and running speed of a tropical arboreal ant ( Cephalotes atratus ) on wet substrates

In the tropical forest canopy, wingless worker ants must cling to and run along diverse vegetative surfaces with little protection from sun, wind and rain. Ants rely in part on their tiny adhesive tarsal pads to maintain sufficient contact with substrates to prevent falls under these varied conditions. Here, we examined the effects of substrate wettability and surface water on the tarsal pad adhesive performance of a common tropical arboreal ant. Ant adhesion was consistently higher on an intermediately wetting substrate (static water contact angle ca 90°) when resisting both perpendicular (normal) force and parallel (shear) force. Normal adhesion was maintained on intermediately wetting and hydrophobic substrates following the addition of rain-mimicking water droplets, whereas shear adhesion declined on all substrate types tested after wetting. Ant running speed was slower on wet substrates. On wood substrates, normal and shear adhesion declined with increasing wetness from dry, to misted, to water-soaked. These differences probably contributed to lower ant running speed on wet wood. The results of this study provide the first quantitative assessment of tropical arboreal ant adhesive performance under substrate conditions that are commonly encountered in the rainforest canopy.

Antigen detection with thermosensitive hydrophilicity of poly(N-isopropylacrylamide)-grafted poly(vinyl chloride) fibrous mats

The static water contact angle of stimuli-responsive fibrous mats is used as a convenient index for rapid antigen detection.