Nonbiofouling surface based on amphiphilic alkanethiol self‐assembled monolayers

A series of novel amphiphilic alkanethiols used for preparation of nonbiofouling surfaces have been synthesized and characterized. Surface properties of the resultant self assembled layers have been studied by multiple characterization techniques, such as XPS, Grazing angle infrared spectroscopy (GA‐FTIR) and contact angle measurements. The antifouling performance of surfaces grafted with terminally fluorinated alkanethiols were assayed employing the fouling diatom Nitzschia and ubiquitous Staphylococcus aureus. The results indicated that amphiphilic alkanethiol‐grafted surfaces could effectively reduce the bacterial adhesion and settlement of the fouling diatom. Copyright © 2010 John Wiley & Sons, Ltd.     

Optical behavior of antibiofouling additives in environment‐friendly coverglass materials for bio‐sensors and solar panels

Solar panels and bio‐optical sensors play a significant and growing role in a number of applications that are of importance to many organizations. Many of these instruments require a high transmission of radiation into the device for it to work properly. A major issue faced is that harsh marine environments often aid in the growth or development of fouling on the coverglass used to protect the instruments. Over a period of time in an ocean environment, some plant or animal may attach itself to the coverglass, ultimately obscuring the glass and rendering the instrument useless. As such, an antifouling mechanism is needed for these instruments that is inexpensive, long‐lasting, and environment friendly. The approach discussed herein involves the use of known antifouling chemicals which have been incorporated into the polymer matrix. Polymethylmethacrylate (PMMA), bisphenol A polycarbonate (Bis A PC), and a co‐polyterephthalate (CPTE) were examined. The plaques are optically transparent and previous work has shown that, for most samples, the materials display a minimal decrease in mechanical behavior upon the addition of the algaecides. This paper will discuss the effects on the materials' optical properties when exposed to both harsh marine conditions as well as high intensity UV light. Specifically, the decrease in transmission of visible light was examined over a 6 month period of time. Copyright © 2008 John Wiley & Sons, Ltd.     

Silver nanoparticles immobilized on thin film composite polyamide membrane: characterization,nanofiltration, antifouling properties

Microbial biofouling is one of the major obstacles for reaching the ultimate goal of realizing a high permeability over a prolonged period of nanofiltration operation. In this study, the hybrid nanocomposite membranes consisting of silver (Ag) nanoparticles with antibiofouling capability on microorganism and polyamide (PA) were prepared by in situ interfacial polymerization and characterized by X‐ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). The hybrid membranes were shown to possess the dramatic antibiofouling effect on Pseudomonas. In addition, Ag nanocomposite membranes had little influence on the performances of the membrane such as on water flux and salt rejection. SEM analysis results showed that all Pseudomonas were dead on the PA/Ag nanocomposite membrane, indicating the effectiveness of silver nanoparticles. This investigation offers a strong potential for possible use as a new type of antibiofouling membrane. Copyright © 2007 John Wiley & Sons, Ltd.     

Amphiphilic pentablock copolymers and their blends with PDMS for antibiofouling coatings

Well‐defined amphiphilic pentablock copolymers Siy‐(EGx‐FAz)₂ composed of polysiloxane (Si), polyethylene glycol (EG), and perfluorohexylethyl polyacrylate (FA) blocks are synthesized by ATRP of FA monomer starting from a difunctional bromo‐terminated macroinitiator. Diblock copolymers EGx‐FAz are also synthesized as model systems. The block copolymers are used, either alone or blended with a PDMS matrix in varied loadings, to prepare antibiofouling coatings. Angle‐resolved XPS and contact angle measurements show that the coating surface is highly enriched in fluorine content but undergoes reconstruction after contact with water. Protein adsorption experiments with human serum albumin and calf serum highlight that diblock copolymers resist protein adhesion better than do pentablock copolymers. Blending of the pentablock copolymer with PDMS results in increased protein adsorption. By contrast, the PDMS‐matrix coatings show high removal percentages of sporelings of the green fouling alga Ulva linza. © 2015 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 2015 , 53, 1213–1225     

Grafting of polyaniline by a dynamic inverse emulsion polymerization technique onto reverse osmosis membranes as an antibiofouling agent

This study reports on the benefits of an in situ interfacial dynamic inverse emulsion polymerization process under sonication of aniline in the presence of a commercial reverse osmosis (RO) membrane. This polymerization method is simple and much faster (5‐15 min) than systems reported in the literature. During polymerization, the membranes are coated with polyaniline (PANI) as verified by high‐resolution scanning electron microscopy (HRSEM) images and Fourier‐transform‐infrared (FTIR) measurements. A colony‐counting antimicrobial activity test showed that whereas the reference RO membrane developed a large bacterial colony, the polyaniline‐coated RO membrane had no colonies at all. Surface resistivity was the lowest when the pH levels were below 6, which corresponded to the polyaniline‐grafted conductive layer. The membrane flow properties were only modified slightly as a result of the polyaniline grafting, compared with a pristine reference membrane.     

Photoinduced Multiple Effects to Enhance Uranium Extraction from Natural Seawater by Black Phosphorus Nanosheets

Based on the photoinduced photothermal, photoelectric, and photocatalytic effects of black phosphorus (BP) nanosheets, a BP‐PAO fiber with enhanced uranium extraction capacity and high antibiofouling activity is fabricated by compositing BP nanosheets into polyacrylamidoxime (PAO). The photothermal effect increases the coordination interaction between UO₂²⁺ and the functional amidoxime group, and the photoelectric effect produces the surface positive electric field that exhibits electrostatic attraction to the negative [UO₂(CO₃)₃]^4?, which all increase the capacity for uranium adsorption. The photocatalytic effect endows the adsorbent with high antibiofouling activity by producing biotoxic reactive oxygen species. Owing to these three photoinduced effects, the photoinduced BP‐PAO fiber shows a high uranium adsorption capacity of 11.76 mg g^?1, which is 1.50 times of the PAO fiber, in bacteria‐containing natural seawater.     

Effect of polydopamine on quaternized poly(ether ether ketone) for antibiofouling anion exchange membrane in microbial fuel cell

Biofouling of anion exchange membranes is a matter of concern in microbial fuel cell. In the present study, we have attempted to improve the antibiofouling potential of anion exchange membrane by using quaternized poly(ether ether ketone) (QPEEK) with surface modification by polydopamine. It is well known that the antiadhesion test tops the list in measuring the antibiofouling potential of the membrane and hence studied. In addition, the effect of dopamine concentration on membrane hydrophilicity and surface roughness was also discussed. From the data, it was clear that power density in all microbial fuel cells showed the highest in the sixth batch and thereafter declined, although at a varying rate. As predicted, QPEEK‐1.0 registered the least. The power density suffered a loss of 918 to 897 mW m⁻² in the case of QPEEK‐1.0, which is the minimum and the same for QPEEK; QPEEK‐0.5 and AMI‐7001 were 918 to 869 mW m⁻², 917 to 885 mW m⁻², and 578 to 537 mW m⁻², respectively. A least value of protein content was obtained for QPEEK‐1.0 (0.21 ± 0.05 g cm⁻²), and the same for QPEEK‐0.5, QPEEK, and AMI 7001 were found to be 0.37 ± 0.05 g cm⁻², 0.78 ± 0.09 g cm⁻², and 1.4 ± 0.11 g cm⁻², respectively. In comparison, the antibiofouling potential of modified membranes was found to be higher than that of unmodified QPEEK and commercially available AMI 7001. The internal resistance values also confirmed that modification with PDA prevents bacteria adhesion leading to high antibiofouling potential.