Static Contact Angle Analysis Research Articles

Microbial colonization patterns and biodegradation of petrochemical and biodegradable plastics in lake waters: insights from a field experiment.

Once dispersed in water, plastic materials become promptly colonized by biofilm-forming microorganisms, commonly known as plastisphere. By combining DNA sequencing and Confocal Laser Scanning Microscopy (CLSM), we investigated the plastisphere colonization patterns following exposure to natural lake waters (up to 77 days) of either petrochemical or biodegradable plastic materials (low density polyethylene - LDPE, polyethylene terephthalate - PET, polylactic acid - PLA, and the starch-based MaterBi® - Mb) in comparison to planktonic community composition. Chemical composition, water wettability, and morphology of plastic surfaces were evaluated, through Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), and static contact angle analysis, to assess the possible effects of microbial colonization and biodegradation activity. The phylogenetic composition of plastisphere and planktonic communities was notably different. Pioneering microbial colonisers, likely selected from lake waters, were found associated with all plastic materials, along with a core of more than 30 abundant bacterial families associated with all polymers. The different plastic materials, either derived from petrochemical hydrocarbons (i.e., LDPE and PET) or biodegradable (PLA and Mb), were used by opportunistic aquatic microorganisms as adhesion surfaces rather than carbon sources. The Mb-associated microorganisms (i.e. mostly members of the family Burkholderiaceae) were likely able to degrade the starch residues on the polymer surfaces, although the Mb matrix maintained its original chemical structure and morphology. Overall, our findings provide insights into the complex interactions between aquatic microorganisms and plastic materials found in lake waters, highlighting the importance of understanding the plastisphere dynamics to better manage the fate of plastic debris in the environment.

Synthesis of a Hydroxyl-Containing Corrosion Inhibitor and Its Inhibitory Performance on N80 Steel in Hydrochloric Acid Solution

In the process of petroleum exploitation, in order to effectively inhibit the corrosion damage of acid to metal equipment. Mannich base corrosion inhibitors are generally added to inhibit the corrosion damage of acid. In order to enhance the solubility of Mannich base corrosion inhibitor. This paper intends to introduce hydrophilic groups to enhance the solubility of the Mannich base corrosion inhibitor. In this paper, two efficient corrosion inhibitors 3-(2-hydroxyethylamino)-1-phenylpropan-1-one (MY1) and 3-(2-aminoethylamino)-1-phenylpropan-1-one (MY2), were synthesized based on the Mannich reaction, using formaldehyde, acetophenone and ethanolamine/ethylenediamine as reaction raw materials. The corrosion inhibition performance of the inhibitor on N80 steel in 15% (mass fraction) hydrochloric acid solution was studied by means of the static weight loss method, electrochemical test and optical contact angle analysis. It could be seen from the static weight loss method that the corrosion rate in the hydrochloric acid solution before and after adding 0.7% (mass fraction) corrosion inhibitor concentration decreased from 129.39 g·m−2·h−1 to 1.45 g·m−2·h−1 and 2.79 g·m−2·h−1, respectively. The corrosion inhibition rate could reach 98%, indicating that both inhibitors had good corrosion inhibition performance, and the corrosion inhibition effect of MY1 was better than that of MY2. It was found from the electrochemical tests that the two inhibitors were mixed corrosion inhibitors mainly inhibiting the anodic reaction, and both inhibitors belonged to spontaneous adsorption, and their adsorption behaviors followed the Langmuir adsorption isotherm. In addition, the surface of N80 steel was characterized by SEM, EDS elemental mapping and contact angle measurement. The results show that a dense hydrophobic film is formed on the surface of the steel sheet after the addition of a corrosion inhibitor, which prevents corrosion.

Antibacterial and Fluorescence Staining Properties of an Innovative GTR Membrane Containing 45S5BGs and AIE Molecules In Vitro.

This study aimed to add two functional components—antibacterial 45S5BGs particles and AIE nanoparticles (TPE-NIM+) with bioprobe characteristics—to the guided tissue regeneration (GTR) membrane, to optimize the performance. The PLGA/BG/TPE-NIM+ membrane was synthesized. The static water contact angle, morphologies, and surface element analysis of the membrane were then characterized. In vitro biocompatibility was tested with MC3T3-E1 cells using CCK-8 assay, and antibacterial property was evaluated with Streptococcus mutans and Porphyromonas gingivalis by the LIVE/DEAD bacterial staining and dilution plating procedure. The fluorescence staining of bacteria was observed by Laser Scanning Confocal Microscope. The results showed that the average water contact angle was 46°. In the cytotoxicity test, except for the positive control group, there was no significant difference among the groups (p > 0.05). The antibacterial effect in the PLGA/BG/TPE-NIM+ group was significantly (p < 0.01), while the sterilization rate was 99.99%, better than that in the PLGA/BG group (98.62%) (p < 0.01). Confocal images showed that the membrane efficiently distinguished G+ bacteria from G− bacteria. This study demonstrated that the PLGA/BG/TPE-NIM+ membrane showed good biocompatibility, efficient sterilization performance, and surface mineralization ability and could be used to detect pathogens in a simple, fast, and wash-free protocol.

Iodine Immobilized UiO-66-NH2 Metal-Organic Framework as an Effective Antibacterial Additive for Poly(ε-caprolactone).

Iodine has been widely used as an effective disinfectant with broad-spectrum antimicrobial potency. However, the application of iodine in an antibacterial polymer remains challenging due to its volatile nature and poor solubility. Herein, iodine immobilized UiO-66-NH2 metal-organic framework (MOF) (UiO66@I2) with a high loading capacity was synthesized and used as an effective antibacterial additive for poly(ε-caprolactone) (PCL). An orthogonal design approach was used to achieve the optimal experiments’ conditions in iodine adsorption. UiO66@I2 nanoparticles were added to the PCL matrix under ultrasonic vibration and evaporated the solvent to get a polymer membrane. The composites were characterized by SEM, XRD, FTIR, and static contact angle analysis. UiO-66-NH2 nanoparticles have a high iodine loading capacity, up to 18 wt.%. The concentration of iodine is the most important factor in iodine adsorption. Adding 0.5 wt.% or 1.0 wt.% (equivalent iodine content) of UiO66@I2 to the PCL matrix had no influence on the structure of PCL but reduces the static water angle. The PCL composites showed strong antibacterial activities against Staphylococcus aureus and Escherichia coli. In contrast, the same content of free iodine/PCL composites had no antibacterial activity. The difference in the antibacterial performance was due to the different iodine contents in the polymer composites. It was found that MOF nanoparticles could retain most of the iodine during the sample preparation and storage, while there was few iodine left in the free iodine/PCL composites. This study offers a common and simple way to immobilize iodine and prepare antibacterial polymers with low antiseptic content that would reduce the influence of an additive on polymers’ physical properties.

Mesogenic Properties of Aromatic Oligoesters Derived from Kink-Structured Monomers

Novel liquid crystalline oligomers were prepared using different compositions of kink-structured aromatic dicarboxylic acids, aromatic diols, and 4-hydroxybenzoic acid via high-temperature polycondensation. The reaction products were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and polarized optical microscopy. As a result, the samples containing kinked units with phenyl or naphthalene moiety had a broad processing window limited by the melting process and the isotropization, whereas one based on diphenic acid was almost entirely in an amorphous state. The surface properties of the oligomers were evaluated by wetting measurements using a static contact angle analysis.

Improvement of thermal-hydraulic performance of plate heat exchanger by electroless nickel, copper and silver plating

In this study, electroless plating of nickel, copper, and silver is applied to stainless steel 316 (SUS316) plate heat exchanger (PHE) to enhance thermal-hydraulic efficiency. The electroless plating experiment was first performed on small samples (30 × 30 × 1 mm) to determine optimum control parameters, i.e. solution concentration, current density, etching time prior to commercial PHE. The characteristics of the coating surfaces were indicated by static contact angle, thermal shock, roughness profile, Vickers hardness, SEM images, and EDS analysis. In order to research the effect of each electroless coating on PHE performance, a single-phase water flow heat transfer experiment was performed. The thermal-hydraulic efficiency was evaluated using the Overall Heat Transfer Coefficient (OHTC), Friction Factor, Number of Transfer Units (NTU), effectiveness and Performance of Evaluation Criterion (PEC). As a consequence, aqua regia solution with a volumetric ratio of 1HNO3: 2HCl: 75H2O, a current density of 0.1 A/cm2 and a 12-min etching were determined to be the optimum process parameters for optimizing surface area and minimizing mass loss. After electroless coating, the surface was completely changed from smooth to rough, resulting in a change from hydrophobicity to hydrophobicity, as well as a change in surface morphology. More significantly, all coated PHEs displayed a substantial increase in their performance, as shown by PEC ranging from 1.21 to 1.30 in the case of Silver-coated PHE, followed by 1.20–1.24 and 1.11–1.15 in the case of Copper and Nickel respectively.

Cinnamaldehyde incorporated gellan/PVA electrospun nanofibers for eradicating Candida biofilm

Immunocompromised patients encounter fungal infections more frequently than healthy individuals. Conventional drugs associated health risk and resistance, portrayed fungal infections as a global health problem. This issue needs to be answered immediately by designing a novel anti-fungal therapeutic agent. Phytoactive molecules based therapeutics are most suitable candidate due to their low cytotoxicity and minimal side effects to the host. In this study, cinnamaldehyde (CA), an FDA approved phytoactive molecule present in cinnamon essential oil was incorporated into gellan (GA)/poly vinyl alcohol (PVA) based electrospun nanofibers to resolve the issues like low water solubility, high volatility and irritant effect associated with CA and also to enhance its therapeutic applications. The drug encapsulation, morphology and physical properties of the synthesized CA nanofibers were evaluated by FESEM, AFM, TGA, FTIR and static water contact angle analysis. The average diameters of CA encapsulated GA/PVA nanofibers and GA/PVA nanofibers were recorded to be 278.5 ± 57.8 nm and 204.03 ± 39.14 nm, respectively. These nanofibers were evaluated for their anti-biofilm activity against Candida using XTT (2, 3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)-carbonyl]-2H-tetrazolium salt) reduction assay. Data demonstrated that CA encapsulated GA/PVA nanofibers can effectively eradicate 89.29% and 50.45% of Candida glabrata and Candida albicans biofilm respectively. CA encapsulated nanofibers exhibited brilliant antimicrobial property against Staphylococcus aureus and Pseudomonas aeruginosa. The cytotoxicity assay demonstrated that nanofibers loaded with CA have anticancer properties as it reduces cell viability of breast cancer cells (MCF-7) by 27.7%. These CA loaded GA/PVA (CA-GA/PVA) nanofibers could be used as novel wound dressing material and coatings on biomedical implants to eradicate biofilm.

Facile construction of stable hydrophobic surface via covalent self-assembly of silane-terminated fluorinated polymer

A facile strategy was developed to construct stable hydrophobic surface via the covalent self-assembly of silane-terminated fluorinated polymer as surface-attached polymer, which was synthesized by the free radical polymerization of 2-(perfluorohexyl)ethyl methacrylate (FOL) with γ-mercaptopropyltrimethoxysilane (MPS) as chain transfer agent. The synthesis condition for the silane-terminated fluorinated polymer (f-PFOL) and coating condition for the covalent hydrophobic coating on the Silicon (Si100) wafer were optimized with the static contact angle analysis, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) measurements. The surface-free energies (γs) was stable at around 9.5 mJ/m2 after washing off the non-functionalized poly(2-(perfluorohexyl)ethyl methacrylate) (PFOL), with the f-PFOL/PFOL mixture solution concentration higher than 0.045 g/mL. The proposed approach provides a universally applicable coating technique for the stable hydrophobic surface on various substrates.

Effect of sandblasting combined with femtosecond laser-etching on surface physicochemical properties of pure titanium

The aim of this study was to generate periodic microstructures on pure titanium surface by femtosecond laser-etching after sandblasting, and to assess the physicochemical properties of its surface. Twelve pure titanium discs with diameter of 10 mm and thickness of 4 mm were used and divided into 3 groups according to different surface treatment methods: group S (sandblasting surface), group SA (sandblasting surface with acid-etching), and group SL (sandblasting surface with femtosecond laser-etching). Scanning electron microscopy (SEM) was used to observe the surface morphology. X-ray energy spectrum(EDS) was used to observe the surface chemical compositions. Three dimensional surface topography and surface roughness were evaluated by laser scanning confocal microscope (CLSM). The static contact angle was detected by high temperature wetting angle measuring instrument. SPSS19.0 software package was used for statistical analysis. SEM and CLSM showed well-distributed periodic and cyclic microstructure which formed second-order roughness composite structure in group SL. EDS analysis showed that the Al element on SL surface decreased (group SL 4.37%<group S 5.18%<group SA 7.27%), and the ratio of O/Ti increased (group SL 1.74>group SA 0.32>group S 0). Surface roughness analysis showed that surface roughness significantly increased in group SL [group SL (7.33±0.38)μm>group SA (1.08±0.12)μm>group S (1.05±0.14)μm](P<0.001). Static contact angle analysis showed that the static contact angle of surface was significantly reduced in group SL [group SL (34.4±2.5)°<group SA (65.0±2.9)°<group S (83.7±2.6)°] (P<0.001). Sandblasting combined with femtosecond laser-etching of pure titanium surface has excellent surface physicochemical properties and is a promising surface modification technology for titanium implant.

Hydrophobic surface via coating fluorinated homopolymer: Effects of the surface etching of silicon wafer and coated fluoropolymer amount

Hydrophobic and superhydrophobic surfaces have attracted more and more interests for various potential applications. Surface topography and chemistry are the main determining factors for the superhydrophobic surfaces. In the present work, the effects of the substrate surface etching and the coated fluoropolymer amount on the hydrophobic coatings were investigated with poly(2-(perfluorohexyl)ethyl methacrylate) (PFOL) as a model fluorinated homopolymer and silicon wafer as a model substrate. Based on the static contact angle and atomic force microscopy (AFM) analysis, the structure model was proposed for the hydrophobic coatings fabricated with different PFOL concentrations: the isolated high mountains of PFOL was formed on the etched silicon (e-Si) wafers with less PFOL amounts, while the low PFOL hills on a sprawling PFOL film with more PFOL, regardless of the original surface roughness before coating. Thus, the textured hydrophobic surfaces with nanoscale roughness could be easily obtained by a facile coating method, owing to the surface segregation of the fluorinated homopolymer.

Study on the preparation and corrosion inhibition of Schiff-base self-assembled membranes

Purpose This paper aims to evaluate the inhibitive effect and adsorption behavior of the 2-amino-5-thiol-1,3,4-thiadiazole vanillin (A) on copper in 3 per cent NaCl solution. Design/methodology/approach A thiazole Schiff bases were synthesized, named, 2-amino-5-thiol-1,3,4-thiadiazole vanillin (A), which was fabricated respectively on copper surface by the molecular self-assembled. Evaluation was carried out by electrochemical measurement and surface analysis techniques. Measurement of static friction coefficient scanning electron microscopy and Contact angle analysis were applied, and it is finally confirmed the existence of the adsorbed film. The inhibitive mechanism of A was evaluated by means of quantitative calculation and molecular dynamics simulation. Findings The electrochemical measurement indicated that the self-assembled molecular film can effectively inhibit the corrosion of copper sheet, when the concentration was 15 mmol⋅L−1 and the assembly time was 6 h, the corrosion inhibition effect was the best, reaching as high as 97.5 per cent. Scanning electron microscopy results showed that the Schiff base compound forms a protective film on the surface of the copper, which effectively blocks the transfer of corrosion particles to the metal substrate, thereby inhibiting the occurrence of corrosion. Adsorption behavior of A followed the Langmuir’s adsorption isotherm and attributed to mixed-type adsorption. The results of Quantitative calculation and molecular dynamics simulation showed that A was adsorbed on Cu (111) surface in parallel. Research limitations/implications In this study, the corrosion inhibition properties of Schiff base film were investigated by combining theory with experiment. Theoretical calculation is helpful to guide the synthesis of efficient and environmentally friendly corrosion inhibitors. Practical implications The damage caused by metal corrosion is great. The self-assembled Schiff base membrane synthesized in this paper is simple and compact, and the corrosion inhibition efficiency of copper in 3 per cent NaCl solution is 97.5 per cent. Social implications Inhibition of metal corrosion can better save energy and reduce economic losses. Originality/value The synthesized Schiff base was prepared on the copper surface by the molecular self-assembled. The Schiff base membrane has a good corrosion inhibition effect on copper in 3 per cent NaCl solution, and the corrosion inhibition efficiency is up to 97.5 per cent.

Surface evaluation of reactive plasma-modified microporous polypropylene membrane by static contact angle analysis

The surface modification of micro-porous polypropylene membrane is achieved by low-pressure reactive plasma treatments using Ar and He gases. The reactive plasma modified microporous polypropylene membranes which are used as the battery separators were evaluated by the electrochemical performance and static contact angle analysis. It is found that the plasma modified polypropylene separators obtain the superior property for Lithium-ion battery and the variations in surface wettability and surface free energy were examined by static contact angle measurement. The static water contact angle of the plasma-modified polypropylene membrane separator significantly decreased with rising plasma power input at both glow region and remote region in the reactive plasmas. An obvious increase in the surface energy of microporous polypropylenes because of low molecular weight oxidized materials from Ar and He plasma treatment was observed in the rinsing process by static contact angle analysis. The experimental results show the vital part of low molecular weight oxidized materials in the interaction between reactive plasma and polypropylene membrane, which can be controlled by the surface modification to tailor the hydrophilicity of micro-porous polypropylene membrane.

Enhanced performance of polyvinylidene fluoride ultrafiltration membranes by incorporating TiO2/graphene oxide

Aiming to enhance the water flux and anti-fouling performance of poly(vinylidene fluoride) (PVDF) ultrafiltration membranes, TiO2–GO/PVDF membranes were first fabricated via blending and immersion precipitation phase inversion. Following that, TiO2–GO nanocomposites grafted with different polyethylene glycol (PEG) were employed as the additives to prepare the novel PVDF hybrid membranes. FTIR spectroscope, SEM, zeta potentiometer, and static contact angle analyzer were employed to characterize the structure and surface properties of the hybrid membranes. Ultrafiltration was used to evaluate the membrane performance. Results showed that the interaction between GO and TiO2 led to the good distribution of TiO2–GO in the polymeric membrane, which increased the polarity and porosity of the hybrid membranes, thus increasing their water flux and anti-fouling performance. The maximum flux of hybrid membranes was four times that of the neat PVDF membrane. The PEG grafted on the TiO2–GO nanocomposites did not only act as a pore-forming additive, but also improved the hydrophilicity and porosity of the hybrid membrane due to the enhancement on the distribution and surface polarity of TiO2–GO. Therefore, both the flux and anti-fouling performance of PVDF membranes containing PEG-modified TiO2–GO were significantly higher than those of membranes including unmodified TiO2–GO.

An investigation into the anti-icing properties of fabrics used for the outer layer of firefighter clothing

The anti-icing properties of fabrics can be considered as involving two parts, the super-hydrophobic property and the ease of ice removal property. In this study, a super-hydrophobic surface was built on to the outer layer of firefighter clothing using nano-silica, C13H13F17O3Si, C19H42O3Si and PU-2540 using a coating method. This coating stops water drops from staying on the fabric surface easily. At the same time, an ultra-smooth surface was built on to the super-hydrophobic surface already created on the fabric using perfluoropolyethers (PFPE) oil by a dipping method, which adds an ice removal function to the fabrics. The anti-icing properties of the samples prepared in the research described in this paper have been investigated using field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), ease of ice removal property tests and static water contact angle analysis. At the same time, the thermal protective performance (TPP) of the samples, before and after super-hydrophobic treatment, was studied by a TPP tester. Results show that the super-hydrophobic coating with an ultra-smooth surface can significantly increase the anti-icing properties of the fabrics used for the outer layer of firefighter clothing. C13H13F17O3Si and C19H42O3Si can improve the hydrophobic properties of the coating. The anti-icing coating in this paper can increase the TPP of the fabrics.

Preparation of superhydrophobic glass fiber and interfacially reinforced glass fiber/epoxy composites by grafting polysiloxane nanowires

Ethyltrichlorosilane used as precursor reacted with glass fiber (GF) surface. Then polysiloxane was functionalized onto GF surface to improve GF’s hydrophobicity and interfacial properties of GF reinforced composites. Fourier transform infrared spectroscopy (FTIR) confirmed the successful grafting of polysiloxane onto GF’s surface. Energy dispersive spectroscopy (EDS) characterized the variation of chemical composition of GF surface. Scanning electron microscopy (SEM) images showed that the polysiloxane was grafted onto GF’s surface uniformly and the surface roughness of GF was enhanced obviously. Static contact angle analysis (SCA) revealed the significant improvement of surface hydrophobicity. Compared with the original GF composites, the interfacial shear strength (IFSS) increased by 36.52%. Meanwhile, we discovered a facile way to accomplish the experiment.

Enhancement of char‐forming and water resistance on ABS modified by poly(4‐nitrophenoxy)‐phosphazene

ABSTRACTPoly(4‐nitrophenoxy)‐phosphazene (DPP) was used as charring and water resistance agent in Acrylonitrile–butadiene–styrene (ABS) composites. The char‐forming capability of DPP and combustion behavior of DPP‐based ABS (ABS‐DPP) were studied by thermogravimetric analysis (TGA) and cone calorimeter, respectively. TGA‐coupled Fourier transform infrared (TGA/FTIR) was used to research the releasing intensity of gaseous products during decomposition. Moreover, the char formation morphology of ABS, DPP, and ABS‐DPP were observed by scanning electron microscopy analysis. The water resistance of DPP was measured by the boiled water tests, the FTIR and static water contact angle analysis. The flame properties of samples and the samples treated by boiled water were studied by LOI and UL‐94, and the tensile properties of ABS‐DPP samples were assessed by tensile testing at high temperature. The results showed that the residues yield of ABS‐DPP samples increased from 0 to more than 20% under nitrogen and from 0.7 to 3.9% under air compared with pure ABS. The combustibility of ABS was decreased by DPP; however, the water resistance of ABS was not affected. At high temperature, tensile strength of ABS‐DPP decreased and the elongation at break enhanced with the addition of DPP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45988.

Double positive effect of adding hexaethyelene glycol when optimizing the hybridization efficiency of a microring DNA detection assay

In this paper, a method for detection of DNA molecules using silicon-on-insulator (SOI) microring resonators is described. The influence of temperature and the use of formamide on the hybridization efficiency were studied. It was shown that 50v/v% of formamide in the hybridization buffer can ensure hybridization when working close to physiological temperature. Furthermore, the use of hexaethylene glycol (HEG) as backfilling agent was studied in order to resolve issues of non-specific adsorption to the surface. The results indicated that not only non-specific binding was reduced significantly but also that HEG improves the orientation of the DNA probes on the surface. This led to a 4-fold increase in hybridization efficiency and thus in an equal decrease in the detection limit, compared to hybridization without the use of HEG. An improvement in robustness of the assay was also observed. This DNA reorientation hypothesis was confirmed by studying the thickness and density of the layers by using dual polarization microring sensing. Finally, the different steps in the sensing experiment were characterized in more detail by static contact angle (SCA) and X-ray photoelectron spectroscopy (XPS) analysis. The results showed quantitatively that the surface modifications were successful.

Study on structural, morphological and thermal properties of surface modified polyvinylchloride (PVC) film under air, argon and oxygen discharge plasma

The effect of air, argon, oxygen DC glow discharge plasma on the polyvinylchloride (PVC) film synthesized by solution casting technique, were evaluated via changes in physio-chemical properties such as structural, morphological, crystalline, thermal properties. The PVC film was plasma treated as a function of exposure time and different plasma forming gases, while other operating parameters such as power and pressure remained constant at 100 W and 2 Pa respectively. The plasma treated PVC were characterized by static contact angle, ATR-FTIR, XPS, AFM and T-peel analysis. It was found that various gaseous plasma treatments have improved the polar components, surface roughness on the surface of PVC which was confirmed by XPS, AFM, resulting in highly enhanced wettability and adhesion. X-ray diffraction study showed that plasma treatment does not persuade considerable change, even though it vaguely induces the crystallinity. The thermal properties of plasma treated PVC were evaluated by Differential Scanning Calorimetry and it was observed that O2 plasma treatment gives higher glass transition temperature of 87.21 °C compared with the untreated one. The glass transition temperature slightly increased for Oxygen plasma treated material due to the presence of higher concentration of the polar functional groups on the PVC surface due to strong intramolecular bonding.

Synthesis of a dodecylphenylsiloxane oligomer resin/silica nanocomposite and its application to cotton fabrics

A novel dodecylphenylsiloxane oligomer resin/nanocomposite (PHDESR-SiO2) was prepared by graft copolymerization between dodecyl modified phenylsiloxane resin with pendent epoxy groups (PHDESR) and amino-functionalized silica nanoparticles (BTEPA-SiO2). PHDESR-SiO2 was then used to prepare a super hydrophobic surface on cotton fabric by a facile solution-immersion process method. Chemical structures, chemical compositions, wettability, surface morphology, and thermal properties were investigated by Fourier Transform Infrared Spectrum (FT-IR), 1H-NMR spectrum, X-ray photoelectron spectroscopy (XPS), static contact angle analyzer, scanning electron microscopy (SEM), Particle size distribution (PSD) and thermo-gravimetric analysis (TGA). The results showed that the target product PHDESR-SiO2 has an anticipative structure with many micro/nanostructure tubercles, a cross-linked network hydrophobic organosilicon resin film and many clusters of cylindrical dodecyl molecular brushes. This created super hydrophobic structure on the surface of the treated cotton fabrics. XPS analysis indicated that the long carbon chain groups had a slight tendency to enrich the film-air interface. In addition, PHDESR-SiO2 can provide good hydrophobicity for the treated fabric. As the dose of PHDESR-SiO2 increased, the hydrophobicity of the treated fabric enhanced and consequently the water static contact angle reached 152.5 °. This had little influence on the softness, color, and gas permeability of the fabrics. This makes it slightly stiff at high doses, and the super-hydrophobic cotton fabric also had good launderability.

Fluorinated alkyne-derived monolayers on oxide-free silicon nanowires via one-step hydrosilylation

Passivation of oxide-free silicon nanowires (Si NWs) by the formation of high-quality fluorinated 1-hexadecyne-derived monolayers with varying fluorine content has been investigated. Alkyl chain monolayers (C16H30−xFx) with a varying number of fluorine substituents (x=0, 1, 3, 9, 17) were attached onto hydrogen-terminated silicon (SiH) surfaces with an effective one-step hydrosilylation. This surface chemistry gives well-defined monolayers on nanowires that have a cylindrical core–shell structure, as characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR) and static contact angle (SCA) analysis. The monolayers were stable under acidic and basic conditions, as well as under extreme conditions (such as UV exposure), and provide excellent surface passivation, which opens up applications in the fields of field effect transistors, optoelectronics and especially for disease diagnosis.