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Supplying clean water to fulfill human requirements is one of this century’s priorities. Global water resources are barely aligned with the rising demand, which is further aggravated by rising population, climate change and water quality problems. Consequently, there is a persistent need for innovative technologies to valorize unconventional water resources such as domestic wastewater. Graphene holds promising prospects in developing domestic wastewater treatment to qualitatively enhance treatment efficiency and quantitatively increase water supply. This review highlights the existing wastewater treatment processes along with their challenges according to South Australian wastewater treatment plants (WWTPs) which are representative of many modern WWTPs. The discussion will also cover the current and potential applications of graphene for domestic wastewater treatment, as well as obstacles and research priorities required for commercialization. Refereed/Peer-reviewed

This paper details Australian commercial and academic silicon research. Areas of interest include silicon metal, polysiloxane polymers, copolymers, cyclics, emulsions, microemulsions, silanes, silane coupling agents, sol-gel chemistry and water-treatments, porous silicon, polysiloxane degradation, silicon hydrogel contact lenses, silanolate synthesis, siloxane interfacial polymerisation, hydrosilylation, polysiloxane electrolytes for lithium ion batteries, silanes for PBX materials, octafunctionalized polyhedral oligomeric silsesquioxanes (POSS), POSS hybrids, sol-gel hydrogenation catalysts, silane modification of silica, sol-gel energy storage, silicate grout stabilisation, GeoPolymer concretes, aerogel insulating foams, “Phaco-Ersatz” Accommodating Gel—Intraocular Lens technologies. Strong collaborative opportunities, in silicon, with Asia, exist with organisations such as: 1) The Asian Silicon Society and 2) The Agency for the Assessment and Application of Technology (BPPT) Indonesia. Refereed/Peer-reviewed

Refereed/Peer-reviewed Although forward osmosis (FO) has escalating prospective applications, several key challenges are still facing this technology, such as membrane fouling, concentration polarization and reverse solute flux. This necessitates the development of novel membranes by integrating nanomaterials that possess extraordinary features such as the evolutionary Graphene (Gr) family nanomaterials. Gr-based nanomaterials have promising ability to be integrated with FO membranes, to enhance water flux and overcome the challenges of FO technology, i.e. reverse solute flux and fouling. In this chapter, the fabricated Gr-based membranes for FO application were evaluated, analysed and compared, particularly the performance of different fabrication strategies including surface modification, free standing and bulk fabrication. Accordingly, here we critically review all the studies performed to integrate Gr materials with FO membranes, focusing on membrane efficiency including water flux and reverse solute flux, in addition to antifouling ability. Moreover, the different strategies for Gr materials integration are assessed.

Graphene (Gr)-based materials are a promising nanomaterial for the development of antibacterial surfaces owing to their biocidal activity. However, the effect of the physicochemical features of these materials on their antibacterial activity has yet to be clarified. Gr-based nanomaterials can interact with cellular components, e.g. membranes, proteins and DNA, and initiate a sequence of nanomaterials/bacterial interactions that rely on colloidal energies and active bio-physicochemical interfaces. Analyzing these different interfaces permits the development of anticipated relations between physical/chemical structure and bactericidal activity depending on Gr-based nanomaterial features such as shape, size, hydrophilicity, roughness and functionality. Realizing how nanomaterials are interacting with bacterial cell membranes is correlated to how they affect bactericidal activity and is thus critical for obtaining benign applications. This review analytically discusses specific Gr-based material features related to bacterial interactions, with special focus on the different modes of interaction between Gr-based materials and cell membranes, nucleic acids and lipid bilayers. Refereed/Peer-reviewed

Fouling of reverse osmosis (RO) membrane is a challenging and restricting aspect in membrane filtration performance,therefore new methods are required to enhance membrane antifouling properties. In this study, a novel surface modification technique for commercial brackish water (BW30LE) thin-film composite (TFC) membrane was applied by using graphene oxide (low GO1 and high GO2) functionalized chitosan (GO/f-Cs). All the membranes including the unmodified one were treated with 200 ppm of sodium hypochlorite and were further characterized by contact angle, scanning electron microscope, atomic force microscopy, UV spectrophotometer and ATR-FTIR. The obtained GO/f-Cs/polyamide (PA) composite membranes showed a superior performance compared to the unmodified PA (TFC) membrane in terms of hydrophilicity, surface smoothness, NaCl rejection,water flux and antifouling property. The unmodified membrane, GO1/f-Cs/PA (M1) and GO2/f-Cs/PA (M2), exhibited permeation fluxes of 56.1, 48.5 and 61.5 L/m2 h and salt rejections of 88.7%, 95.4% and 95.6%, respectively,using 1500 mg/L NaCl concentration as a feed solution under 14 bar. To examine the membrane's dynamic fouling resistance, cross-flow filtration tests were conducted using bovine serumalbumin (BSA).M2 membrane had less flux decline than the unmodified one, and achieved 97% water flux recovery ratio by only water cleaning. Refereed/Peer-reviewed

Filtration membrane technologies are used extensively in dairy processing and due to the high quantities of both organic and inorganic foulant, membrane fouling is a significant problem in the industry. To address this issue, a polyzwitterionic antifouling coating was applied to polyethersulfone ultrafiltration membranes for reduction of biofouling in skim milk filtration. The novel polyzwitterion was synthesised from a branched polyethyleneimine-based macroinitiator to allow multidentate binding to polydopamine coated membranes. Attachment of polyzwitterion to the polydopamine was confirmed using FTIR-ATR and XPS and the coating proved effective in increasing the wettability and smoothness of the membrane surface as well as reducing its charge. The reduced strength of binding between proteins and the membrane of the coated membrane compared to the control was demonstrated with its positive influence on fouling coefficient and recovery of the membranes while retaining skim milk flux and the rejection characteristics of the control membrane. The improved filtration characteristics of the coated membranes were generally retained through multiple cleaning cycles, though there was evidence of oxidative degradation after sanitation. Refereed/Peer-reviewed

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (http://creativecommons.org/licenses/by/3.0/), Biofouling is a serious problem for any wetted structure, having a negative influence on applications as diverse as marine transport, implanted medical devices and water treatment. Here, we address this issue by creating a polydopamine-based coating on desalination reverse osmosis membranes incorporating a bromo-macroinitiator for subsequent polymerisation of sulfobetaine monomers into anti-biofouling polymer brushes. Surface characterisation using attenuated total reflectance-Fourier transform infrared spectroscopy and the water contact angle demonstrated the attachment of the polysulfobetaine brushes and that the hydrophilicity increased for the coated membranes. Using a macroinitiator formation time of ten minutes followed by polyzwitterion coating of one hour resulted in a 17% increase in water flux without significant effect on the salt rejection performance. These membranes also exhibited substantial suppression of protein and bacterial attachment of 69% and 88% respectively compared to unmodified membranes.

Inulin isoforms, especially delta inulin, are important biologically as immune activators and clinically asvaccine adjuvants. In exploring action mechanisms, we previously found regular increments in thermalproperties of the seven-member inulin isoform series that suggested regular additions of some energetic structural unit. Because the previous isolates carried additional longer chains that masked definingranges, these were contrasted with new isoform isolates comprising only inulin chain lengths definingthat isoform. The new series began with 19 fructose units per chain (alpha-1 inulin), increasing regularlyby 6 fructose units per isoform. Thus the ‘energetic unit’ equates to 6 fructose residues per chain. Allisoforms showed indistinguishable X-ray diffraction patterns that were also identical with known inulincrystals. We conclude that an ‘energetic unit’ equates to one helix turn of 6 fructose units per chain asfound in one unit cell of the inulin crystal. Each isoform chain comprised progressively more helix turnsplus one additional fructose and glucose residues per chain. Refereed/Peer-reviewed

This paper investigates the effect of polyhedral oligomeric silsesquioxane (POSS) nanoparticle inclusion in cellulose acetate (CA) membranes. The synthesis of a novel CA-anchored nanoparticle additive (CA-POSS) is described. Membranes were fabricated with no additive, or either the POSS or CA-POSS as an additive at different weight percent loadings. Nanoparticle dispersion was investigated using scanning electron microscopy. Dynamic mechanical analysis was used to investigate the mechanical strength of the nanocomposite membranes. The effect of nanoparticle inclusion on the filtration properties and compaction behavior of the membranes was also investigated. Compared to the CA control, nanocomposite membranes exhibited superior flux and compaction resistance, and decreased salt rejection and mechanical strength. Refereed/Peer-reviewed

Polydopamine and related polycatecholamines can be easily deposited onto almost any surface from mild, aqueous solution. This results in durable, nanoscale coatings that exhibit high biocompatibility and have useful chemical and electronic properties. Additionally, these materials can be readily chemically and physically modified, and consequently, they are used extensively for surface modification. This review investigates the formation and modification of polycatecholamines; how they adhere to surfaces; and the chemical, physical, and electronic properties of the resultant materials. There is also an exploration of the extraordinary array of applications in which these fascinating materials are employed. Refereed/Peer-reviewed

The hydrolysis of various carbohydrates was investigated under acidic conditions in real time by 1H NMR spectroscopy, with a focus on the polysaccharide inulin. Sucrose was used as a model compound to illustrate the applicability of this technique. The hydrolysis of sucrose was shown to follow pseudo first order kinetics and have an activation energy of 107.0 kJ.mol−1 (s.d. 1.7 kJ.mol−1). Inulin, pullulan and glycogen also all followed pseudo first order kinetics, but had an initiation phase at least partially generated by the protonation of the glycosidic bonds. It was also demonstrated that polysaccharide chain length has an effect on the hydrolysis of inulin. For short chain inulin (DPn 18, s.d. 0.70) the activation energy calculated for the hydrolytic cleavage of glucose was similar to sucrose at 108.5 kJ.mol−1 (std. dev. 0.60). For long chain inulin (DPn 30, s.d. 1.3) the activation energy for the hydrolytic cleavage of glucose was reduced to 80.5 kJ.mol−1 (s.d. 2.3 kJ.mol−1). This anomaly has been attributed to varied conformations for the two different lengths of inulin chain in solution.

D-Fructose was analysed by NMR spectroscopy and previously unidentified 1H NMR resonances were assigned to the keto and a-pyranose tautomers. The full assignment of shifts for the various fructose tautomers enabled the use of 1H NMR spectroscopy in studies of the mutarotation (5-25 C) and tautomeric composition at equilibrium (5-50 C). The mutarotation of b-pyranose to furanose tautomers in D2O at a concentration of 0.18 M was found to have an activation energy of 62.6 kJ mol 1. At tautomeric equilibrium (20 C in D2O) the distribution of the b-pyranose, b-furanose, a-furanose, a-pyranose and the keto tautomers was found to be 68.23%, 22.35%, 6.24%, 2.67% and 0.50%, respectively. This tautomeric composition was not significantly affected by varying concentrations between 0.089 and 0.36 M or acidification to pH 3. Upon equilibrating at 6 temperatures between 5 and 50 C there was a linear relationship between the change in concentration and temperature for all forms. Refereed/Peer-reviewed

The synthesis, kinetics, and characterization of polystyrene and poly(methyl methacrylate) block copolymers produced by ARGET ATRP are discussed. Halogen exchange is used and the polymerization appears to be living in the generation of the second block. On further investigation, the GPC traces exhibit a shoulder, which suggests poor initiation of the macroinitiator. Previous reports suggest that to increase the initiation effi ciency of the second block, 10% styrene monomer should be added to the mixture. Upon adding the 10% styrene for the second block ARGET ATRP polymerization, the appearance of a well-initiated polymer is observed. However, at greater conversions the results clearly demonstrate the production of a homopolymer/block copolymer mixture. Refereed/Peer-reviewed

Carbon nanotubes are attractive approach for designing of new membranes for advanced molecular separation because of their unique transport properties and ability to mimic biological protein channels. In this work the synthetic approach for fabrication of carbon nanotubes (CNTs) composite membranes is presented. The method is based on growth of multi walled carbon nanotubes (MWCNT) using chemical vapour deposition (CVD) on the template of nanoporous alumina (PA) membranes. The influence of experimental conditions including carbon precursor, temperature, deposition time, and PA template on CNT growth process and quality of fabricated membranes was investigated. The synthesis of CNT/PA composites with controllable nanotube dimensions such as diameters (30-150 nm), and thickness (5-100 μm), was demonstrated. The chemical composition and morphological characteristics of fabricated CNT/PA composite membranes were investigated by various characterisation techniques including scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDXS), high resolution transmission electron microscopy (HRTEM) and x-ray diffraction (XRD). Transport properties of prepared membranes were explored by diffusion of dye (Rose Bengal) used as model of hydrophilic transport molecule. Refereed/Peer-reviewed

The complex cure kinetics of the reaction between oligomeric diphenylmethane diisocyanate (PMDI) and glycerol was characterized through thermal and rheological techniques. Isoconversional analysis of Differential scanning calorimetry (DSC) data resulted in the activation energy varying with conversion. Isothermal analysis gave activation energies ranging from 5 kJ/mol to 33.7 kJ/ mol, whereas nonisothermal data gave values for the activation energy ranging from 49.5 to 55 kJ/mol. Incomplete cure was evident in isothermal DSC, becoming diffusion controlled in the final stages of cure. DMA analysis on the cured material gave a glass transition temperature of 104 ± 3°C, which was evidence for vitrification of the curing system. The primary and secondary hydroxyl group reactivity was dependant on the isothermal cure temperature. Rheological studies of viscosity increase and tan δ changes with time revealed a complex cure process, with primary and secondary hydroxyl reactivity also showing dependence on isothermal cure temperatures, reflecting similar results obtained from isothermal DSC studies. The independence of tan δ on frequency was used to determine the point where the polymer formed an infinite network and was no longer able to flow, providing an overall activation energy attained at the gel point of 77.4 ± 4.4 kJ/mol. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Omeprazole, commonly used in the treatment of various gastrointestinal disorders degrades rapidly in acidic pHs and results in inter-individual variability due to different rates of metabolism amongst patients. Since S-omeprazole shows more predictable bioavailability and excipients have been known to interact with active pharmaceutical ingredients to produce altered bioavailability, it was decided to investigate the compatibility of omeprazole sodium isomers with mannitol, the major excipient in omeprazole formulations using differential scanning calorimetry (DSC) for bulk drug, attenuated total reflectance (ATR) infrared (IR) spectroscopy in a powder mixture and localized thermal analysis (LTA) from a drug disk. DSC results clearly indicate an interaction between mannitol and R-omeprazole sodium due to decreased melting temperatures and broadening peaks. The DSC of S-omeprazole sodium does not show melting temperature although the drug was crystalline. Because of the accelerated temperature conditions during DSC experiments applied in this work, ATR-IR was undertaken to determine whether these results occurred at room temperature for the solid dosage form. The ATR-IR results show a difference between R- and S-omeprazole sodium with mannitol by the appearance of both the amino (N–H) and imino ( N–H) stretching frequencies for R-omeprazole and only the N–H for the S-omeprazole sodium. It may thus be concluded that different ratios for the tautomeric forms for S- and R-omeprazole sodium result in changes in the degree of crystallinity and are responsible for the interaction with mannitol, common excipient in formulation. These interactions may be directly related to the difference in terms of bioavailability.

Carbon nanotubes (CNTs) are of interest in many areas of nanotechnology and used in a number of novel applications. However effective dispersion remains a problem and one solution is to functionalize the nanotubes. Any functionalization that is undertaken must preferably not influence other key properties such as strength and electrical conductivity. In this work, multi-walled CNTs are functionalized for comparison, using a range of oxidative techniques, including thermal treatment, acid reflux, and dry UV-ozonolysis. The effects of these treatments on the multi-walled carbon nanotubes (MWCNTs) and their electrical properties were characterized using a range of surface and compositional techniques. The electrical conductivity of MWCNTs was found to increase with functionalization in all cases, and dry UV-ozonolysis was shown to be the treatment technique which best increased conductivity, whilst at the same time maintaining the structural integrity of the nanotubes, even though the level of modification was less than by the other treatment methods.

Graphene oxide (GO) nanosheets have anti-bacterial properties that have been exploited as a biocidal agent used on desalination membrane surfaces in recent research. Nonetheless, improved strategies for efficient and stable attachment of GO nanosheets onto the membrane surface are still required for this idea to be commercially viable. To address this challenge, we adopted a novel, single-step surface modification approach using tannic acid cross-linked with polyethylene imine as a versatile platform to immobilize GO nanosheets to the surface of polyamide (PA) thin film composite (TFC) forward osmosis (FO) membranes. An experimental design based on Taguchi’s statistical method was applied to optimize the FO processing conditions in terms of water and reverse solute fluxes. Modified membranes were analyzed using water contact angle (WCA), adenosine triphosphate (ATP) bioluminescence, total organic carbon (TOC), Fourier transform infrared spectroscopy (FTIR), zeta potential, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and atomic force microscopy (AFM). These results show that membranes were modified with a nanoscale (< 10 nm), smooth, hydrophilic coating that, compared to pristine membranes, improved filtration and significantly mitigated biofouling by 33% due to its extraordinary, synergistic antibacterial properties (99.9%). Refereed/Peer-reviewed

A homologous series of PEG (various chain length)-substituted octasilsesquioxanes were prepared by the hydrosilylation of unsaturated PEGs (poly(ethylene glycol)s) with both octa(dimethylsiloxy)silsesquioxane (Q8M8H) and octahydridosilsesquioxane (T8H). The silsesquioxane-PEGs materials were produced by the initial synthesis of a series of allyl-modified poly(ethylene glycol)s and subsequent attachment to both (Q8M8H) and (T8H). The products were chemically characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H, 13C, and 29Si NMR) spectroscopy, and the properties of the allyl PEGs and their POSS hybrids were thermally characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The attachment of the PEGs onto the POSS macromonomers (Q8M8H and T8H) clearly demonstrated a chain-length-dependent increase in Tg and a concomitant suppression of crystallization.

In this work multiwalled carbon nanotubes were examined using a combination of thermal annealing followed by chemical treatments with potassium permanganate solution. Functionalization with carboxylic acid moieties through this newly devised process simultaneously purified and cut the nanotubes. A cutting procedure using potassium permanganate that could keep or remove the MnO2 has not been previously reported, making this study a stepping stone to further functionalization/application opportunities. One such further functionalization was explored here with alkyl groups, through the generation of an amide linkage. A very detailed standard suspension test was performed on this material. What was found was an increased suspension stability toward polar solvents for the nanotubes with high concentrations of MnO2 deposits, and in nonpolar solvents the nanotubes with large alkyl chains attached were observed, thus proving it to be a versatile treatment.

This study combined physical data from synchrotron SAXS, FTIR and microscopy with in-silico molecular structure predictions and mathematical modeling to examine inulin adjuvant particle formation and structure. The results show that inulin polymer chains adopt swollen random coil in solution. As precipitation occurs from solution, interactions between the glucose end group of one chain and a fructose group of an adjacent chain help drive organized assembly, initially forming inulin ribbons with helical organization of the chains orthogonal to the long-axis of the ribbon. Subsequent aggregation of the ribbons results in the layered semicrystalline particles previously shown to act as potent vaccine adjuvants. γ-Inulin adjuvant particles consist of crystalline layers 8.5 nm thick comprising helically organized inulin chains orthogonal to the plane of the layer. These crystalline layers alternate with amorphous layers 2.4 nm thick, to give overall particle crystallinity of 78%. Refereed/Peer-reviewed

Modulated temperature DSC was investigated, comparing data found experimentally to that derived from theory. Deviation from theory was found with regard to the amplitude of the modulated heat flow signal when large modulation amplitudes were employed in the experiment. These deviations were determined to be dependent on the absolute temperature and it was concluded that further investigation of the heat flow signal obtained during MTDSC experiments is required.

This study investigates mechanisms of cold rolling oil removal from the surface of low-carbon steel. The removal process has been probed using thermogravimetric analysis techniques. A range of furnace atmospheres, from non-oxidizing through to highly oxidising, have been used to simulate the oil removal conditions in the industrial process. The activation energies of oil removal under each gas atmosphere have been determined by MTG and the Flynn-Wall-Ozawa method. The results show that a reducing atmosphere is the optimal environment for effective oil removal. Steel-oil surface interactions have also been investigated to show that the steel substrate catalyses oil removal.

This paper presents a thermodynamic investigation of the benzene physical and chemical organogels, using differential scanning calorimetry (DSC) and intends to draw an appropriate relationship between the gel network structure and the properties. Physical gels, formed by an aluminium soap of fatty acid, and chemical gels, created by in situ cross-linking of a siloxane copolymer are investigated. The effects of the type and quantity of the gelators and their corresponding network mesh size distribution in the gels on crystallization, melting, and their kinetics are examined. It appears that the kinetics of crystallization of the entrapped solvent is significantly affected by the quality of the gel network scaffolding and can be treated successfully by the Avrami equation of crystallization. From the melting behavior of the entrapped solvent crystallites, quantitative information about the number of solvent molecules bound per molecule of the gelator has been extracted. DSC proves to be a reliable technique to evaluate the population distribution of solvent molecules trapped in the physical and chemical organogel network scaffolding. The state of the solvent may be treated as a probe to understand the structure of the gels. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1253–1264, 2004

Micro-thermal analysis (mTAe) and temperature-modulated differential scanning calorimetry (TMDSC) are emerging as powerful instruments for identifying the existence and quantities of phases in multi-component systems, as well as interfacial properties. In this study, these two complimentary techniques are utilised to probe the interphase behaviour of a polycarbonate/acrylonitrile – styrene – acrylate (PC/ASA) blend as they develop during injection molding. Micro-thermal analysis revealed that parts manufactured at high injection time, pack pressure and melt temperature show a densely packed bulk morphology, a significant amount of particle agglomeration as well as the formation of styrene – acrylonitrile/PC (SAN/PC) interphases. TMDSC qualitatively and quantitatively characterized the PC/ASA’s multiphase morphology and its interfacial properties both before and after injection molding, indicating a greater amount of PC entering the interphase than SAN. q 2003 Elsevier Science Ltd. All rights reserved.

A detailed investigation on the thermodynamic behaviour of the physical and chemical organogels, using differential scanning calorimetry (DSC) and modulated thermogravimetric analysis (MTGA), is presented. Aluminium soap of fatty acid was used as the physical gelator and in situ crosslinking of siloxane copolymer was used for chemical gelation. The effects of the type and concentration of the gelators and the corresponding mesh-size distribution of the gel network scaffolding on the trapped-solvent crystallization, melting and evaporation mechanism, and kinetics are examined. It appears that the kinetics of crystallization of the trapped-solvent are significantly affected by the quality of the gel network scaffolding and can be treated successfully by the Avrami equation of crystallization. From the melting behaviour of the entrapped-solvent crystallites, quantitative information about the number of solvent molecules bound per molecule of the gelator has been extracted. The effect of gelation network structure on the kinetics of evaporation of the solvent from the gel network scaffolding has been evaluated. DSC appears to be the reliable technique to evaluate the population distribution of solvent molecules trapped in the gel network scaffolding. Copyright © 2003 Society of Chemical Industry

Although reverse osmosis technology appears to be maturing, several major challenges remain including membrane fouling. The most problematic type of fouling is biofouling because even small amounts of microorganisms that escape pretreatment processes can colonize the system, multiplying the problem at the membrane surface. To address this issue we have created an industrially attractive process suitable for the grafting of polysulfobetaine onto commercially available reverse osmosis membrane surfaces to create an anti-fouling coating. Attachment of coating components was confirmed using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Water contact angle (WCA) and transmission electron microscopy (TEM) then illustrated that the polysulfobetaine coating increased both the hydrophilicity and smoothness of the membrane surface. This modification resulted in at least 80% reduction in microbial abundance at the surface in both aquaria-based static tests and hydrodynamic cross-flow filtration tests while exhibiting flux and salt rejection comparable to controls. The potential applications of this technology include sea water reverse osmosis membranes and alternative feed water sources Refereed/Peer-reviewed

Graphene oxide (GO) nanosheets were attached to the polyamide selective layer of thin film composite (TFC) forward osmosis (FO) membranes through a poly L-Lysine (PLL) intermediary using either layer-by-layer or hybrid (H) grafting strategies. Fourier transform infrared spectroscopy, zeta potential, and thermogravimetric analysis confirmed the successful attachment of GO/PLL, the surface modification enhancing both the hydrophilicity and smoothness of the membrane’s surface demonstrated by water contact angle, atomic force microscopy, and transmission electron microscopy. The biofouling resistance of the FO membranes determined using an adenosine triphosphate bioluminescence test showed a 99% reduction in surviving bacteria for GO/PLL-H modified membranes compared to pristine membrane. This antibiofouling property of the GO/PLL-H modified membrane was reflected in reduced flux decline compared to all other samples when filtering brackish water under biofouling conditions. Further, the high density and tightly bound GO nanosheets using the hybrid modification reduced the reverse solute flux compared to the pristine, which reflects improved membrane selectivity. These results illustrate that the GO/PLL-H modification is a valuable addition to improve the performance of FO TFC membranes. Refereed/Peer-reviewed

Semi-crystalline microparticles of inulin (MPI) have clinical utility as potent human vaccine adjuvants but their relevant surface structure and crystal assembly remain undefined. We show inulin crystal surfaces to resemble multi-layered, discoid radial spherulites resulting from very rapid formation of complex tertiary structures, implying directed crystal initiation. Physical and in silico molecular modelling of unit cells confirm steric feasibility of initiation by hydrogen-bonded cross-linking of terminal glucose to a fructose of another chain, mimicking bonding in sucrose crystals. A strong, chelate-like dual H-bond is proposed to compel the known antiparallel alignment of inulin chains. Such cross-linking would require one extra fructose per chain in the native inulin crystal, as observed. Completion of five H-bonded internal ring-domains would ‘lock in’ each new 6-fructose structural unit of each antiparallel helix pair to create a new isoform. All known properties of inulin isoforms follow readily from these concepts. Refereed/Peer-reviewed

The present investigation deals with studies on wettability, miscibility, and morphology of the macromolecularly modified EPDM. Two different maleated EPDM rubbers (grafted rubber) were chosen (0.5 and 1% maleation) for such modification and they were used in various proportions. Wettability of the rubber substrate, as observed from dynamic contact angle measurement, was improved using these grafted rubbers. Results of X-ray photoelectron spectroscopy showed an increase in oxygen level with higher levels of grafted rubber in the blends. Morphology study by transmission electron microscopy showed a smaller domain size for the blend with higher maleic anhydride content in the grafted rubber. The viscosity versus blend ratio results showed a negative deviation behavior for blends with 1% grafted rubber, whereas a positive negative deviation behavior was observed in blends with 0.5% grafted EPDM. As the strength of interaction increased, the glass transition shifted to a higher temperature. All blends were heterogeneous, as indicated by different degrees of dispersion. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2647–2661, 2001

The present investigation focuses on matching cure characteristics of EPDM rubber compound and polyurethane (PU) coating using temperature modulated and pressure differential scanning calorimetry (TMDSC, PDSC). TMDSC provides a detailed and better understanding of the curing process of model rubber system as well as complex automotive rubber compounds. The low level of unsaturation present in EPDM, results in the small heat of vulcanization (2–5 J g –1 ), which is difficult to accurately measure using conventional differential scanning calorimetry (DSC). Thus, curing of highly filled EPDM compound was investigated using TMDSC. The kinetics of PU curing was monitored using pressure DSC (PDSC), and heat of curing was determined as 4.2 J g –1 at 10°C min –1 heating rate. It is found that complex automotive compounds and the PU coating are curing simultaneously.

The viscoelastic behaviour of gum and a highly filled ethylene-propylene terpolymer (automotive windowseal component) at 138 parts carbon black loading was investigated using a dynamic mechanical analyser over a wide range of time, temperature, strain and frequency. The tensile stress relaxation and recovery results of the gum system show time-dependent but strain-invariant behaviour, whereas the filled system shows both strain and time dependence. The relaxation time spectrum of the filled system reveals nonlinear viscoelastic behaviour. The networks of carbon black formed at such a high loading contribute significantly to the relaxation process. The 3D plot of tensile modulus as a function of time and temperature for both the systems follow a similar trend, and even for short-time testing the highly filled system appears to be time–temperature superposable.

Polymeric composites for automotive window seal applications are generally exposed to complex service environment conditions. The fundamental physico-chemical processes that control the durability of such composite systems on a micro and macroscopic level were evaluated in the present case using thermal analysis (TA), elemental mapping and microscopy. Five diAerent EPDM rubber compounds (control, three bulk modified and one surface modified), coated with polyurethane coating were exposed to controlled UV irradiation. The higher the adhesion, the less the extent of UV penetration through the interface. The photo-oxidation mainly takes place from the surface, as the energy gets consumed and the intensity of the UV decreases on its passage through the strongly adhered layers to the rubber compound. The coating layer being on the surface, is more aAected and photodegraded by UV irradiation than the rubber compound. The sample P1cc, being multiphasic in nature and with a strong interface, can scatter the UV strongly and hence shows best weatherability among all the systems. # 2000 Elsevier Science Ltd. All rights reserved.

A two-pack polyurethane coating was analyzed using thermoanalytical techniques. The curing reaction, monitored using pressure differential calorimetry (PDSC), rheometry and dynamic mechanical analysis (DMA) shows the temperature dependency of activation energy and hence rate of curing. In-situ ATR-FTIR shows the formation of urethane linkage over time. The decomposition behavior carried out under non-isothermal mode using thermogravimetric analysis (TGA) shows bimodal behavior. The activation energies of the initial step (10% decomposition) from both iso and non-isothermal experiments are in very good agreement with each other. The use of dynamic mechanical analysis (DMA) shows the difference in glass transition behavior (Tg) and elastic modulus (E') due to the different state of cure. Also the coating exhibits a very broad loss modulus peak (E'') indicating higher energy dissipation with deformation.

As rubber formulations are complex mixtures of different additives, many of them often migrate and diffuse to the surface, resulting in poor adhesion of windowseal rubber to coating. The present work was conducted to identify and quantify the diffusion behavior of additives of different rubber samples [masterbatch and final automotive ethylene propylene diene (EPDM) rubber compounds] using different complementary techniques such as contact angle measurements, X-ray photoelectron spectroscopy (XPS), size exclusion chromatography (SEC), and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The influence of different methods of processing (milling and extrusion) on the diffusion behavior and change in rubber surface chemistry was investigated. Contact angle measurements using scanning Wilhelmy and sessile drop methods over prolonged time mainly showed an increase in the polar component of the surface energy for the samples, although the total surface energy did not change signi...

In studying the molecular basis for the potent immune activity of previously described gamma and delta inulin particles and to assist in production of inulin adjuvants under Good Manufacturing Practice, we identified five new inulin isoforms, bringing the total to seven plus the amorphous form. These isoforms comprise the step-wise inulin developmental series amorphous → alpha-1 (AI-1) → alpha-2 (AI-2) → gamma (GI) → delta (DI) → zeta (ZI) → epsilon (EI) → omega (OI) in which each higher isoform can be made either by precipitating dissolved inulin or by direct conversion from its precursor, both cases using regularly increasing temperatures. At higher temperatures, the shorter inulin polymer chains are released from the particle and so the key difference between isoforms is that each higher isoform comprises longer polymer chains than its precursor. An increasing trend of degree of polymerization is confirmed by end-group analysis using (1)H nuclear magnetic resonance spectroscopy. Inulin isoforms were characterized by the critical temperatures of abrupt phase-shifts (solubilizations or precipitations) in water suspensions. Such (aqueous) "melting" or "freezing" points are diagnostic and occur in strikingly periodic steps reflecting quantal increases in noncovalent bonding strength and increments in average polymer lengths. The (dry) melting points as measured by modulated differential scanning calorimetry similarly increase in regular steps. We conclude that the isoforms differ in repeated increments of a precisely repeating structural element. Each isoform has a different spectrum of biological activities and we show the higher inulin isoforms to be more potent alternative complement pathway activators.

We report on a method to preferentially align multiwall carbon nanotubes (MWCNTs) in a liquid crystalline matrix to form stable composite thin films. The liquid crystalline monomeric chains can be crosslinked to form acrylate bridges, thereby retaining the nanotube alignment. Further post-treatment by ozone etching of the composite films leads to an increase in bulk conductivity, leading to higher emission currents when examined under conducting scanning probe microscopy. The described methodology may facilitate device manufacture where electron emission from nanosized tips is important in the creation of new display devices.

To improve biofouling resistance, cellulose acetate (CA) reverse osmosis membranes were modified by reacting surface hydroxyl groups with an atom transfer radical polymerization (ATRP) initiator, 2- bromoisobutyryl bromide, followed by polymeric grafting of 2-hydroxyethyl methacrylate (pHEMA) using activators regenerated by electron transfer (ARGET) ATRP. Thermogravimetric analysis (TGA), atomic force microscopy (AFM) and water contact angle (WCA) measurements of pristine and modified membranes were performed to measure and compare the amount of polymer deposited, the surface morphology and the hydrophilicity of the surfaces, respectively. Roughness and hydrophilicity increased with graft density. The biofouling resistance of pHEMA-modified membranes immersed in seawater aquarium tanks was compared to pristine membranes and the effect of pHEMA coating on water flux and NaCl rejection was measured. Based on stirred-cell and aquaria experiments, pHEMA-modified membranes with low graft density showed just a 6% decrease in salt rejection and water flux relative to pristine CA membranes, and a 24% improvement in resistance to seawater microbial biofouling. Refereed/Peer-reviewed

The synthesis and characterization of multiwalled carbon nanotube (MWCNT) polymer brushes produced by activators regenerated by electron transfer (ARGET) in atom-transfer radical polymerization (ATRP) was discussed. The polymer brushes were synthesized by esterification of the MWCNT carboxylic acid groups with hydroxyethyl-2-bromoisobutyrate and subsequently used in ARGET ATRP. This created a well defined living polymer brush carbon nanotube of comparatively low polydispersity and a polymer layer 10 nm thick. As, ARGET ATRP uses only minute concentrations of copper (II) catalyst, and is less sensitive to air compared to other living polymerization techniques, this process is a more industry-compatible route for the commercialization of such materials. The structural and chemical properties were explored by a range of techniques including high resolution transmission electron microscopy, gel permeation chromatography, elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. In addition, the polymer brush nanotubes were explored for their potential use in films and as fillers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Surfactant modified zeolites (SMZs) have the capacity to target various types of water contaminants at relatively low cost and thus are being increasingly considered for use in improving water quality. It is important to know the surfactant loading performance of a zeolite before it is put into application. In this work we compare the loading capacity of a surfactant, hexadecyltrimethylammonium bromide (HDTMA-Br), onto four natural zeolites obtained from specific locations in the USA, Croatia, China, and Australia. The surfactant loading is examined using thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, and Raman spectroscopy. We then compare the resulting SMZs performance in removing nitrate from water. Results show that TGA is useful to determine the HDTMA loading capacity on natural zeolites. It is also useful to distinguish between a HDTMA bi-layer and a HDTMA mono-layer on the SMZ surface, which has not been previously reported in the literature. TGA results infer that HDTMA (bi-layer) loading decreases in the order of US zeolite>Croatian zeolite>Chinese zeolite>Australian zeolite. This order of loading explains variation in performance of nitrate removal between the four SMZs. The SMZs remove 8-18 times more nitrate than the raw zeolites. SMZs prepared from the selected US and Croatian zeolites were more efficient in nitrate removal than the two zeolites commercially obtained from Australia and China.

The formation of persistent residues by esters used in sheet metal-working lubricant formulations interferes with metal surface cleanliness and impairs the integrity of subsequent surface coatings. Understanding the thermal decomposition and residue formation properties of esters is therefore crucial to minimising residue formation during furnace-based cleaning and will aid in the improvement of coated metal products such as galvanised steel. The thermo-oxidative decomposition profiles of four different methyl esters were studied by Thermogravimetric Analysis (TGA) and Pressure Differential Scanning Calorimetry (PDSC). Chemical characterisation of residues remaining at different stages during the thermo-oxidative decomposition process was achieved by infrared spectroscopic analysis of TGA residue samples. Relationships between ester alkyl chain unsaturation levels and the amount/chemical nature of residue present at high temperature (500 °C) were assessed. In the presence of oxygen, polyunsaturated esters decomposed to leave significantly greater amounts of thermally-stable residue, comprising of metal carboxylate and non-volatile oxygenated compounds, than more saturated esters. Given that the formation of analogous residues by more complex esters used in sheet metal-working lubricants may give rise to metal surface coating defects, the results of this study suggest that polyunsaturated esters should be avoided in lubricant formulations where preventing residue formation is of paramount importance.

Reaction rate and kinetics of cure between PMDI and castor oil, a tri-functional polyol, for stoichiometric and off-stoichiometric mole ratios, were studied through isoconversional analysis of DSC data and through gelation times and viscosity build up obtained through rheological techniques. The cure kinetics of the polyurethane reaction as monitored using different techniques gave similar activation energies for the stoichiometric ratio. Isoconversional analysis of DSC data showed a competitive reaction scheme for the stoichiometric system, suggesting the presence of isocyanate groups with different reactivities in the PMDI, which was further substantiated in rheological investigations.

Exposure of a Au(111) surface to ethynylbenzene in solution leads to the formation of a bound monolayer. A chemisorption process occurs to give a stable layer consisting of oxygen-containing hydrocarbon species. Ethynylbenzene itself does not oxidize under the deposition conditions indicating that the gold surface facilitates the oxidation process. Calculations show that ethynylbenzene and its oxidation products phenylacetic acid and phenyloxirane have positive binding energies to the gold surface. 1,4-Diethynylbenzene also binds to Au(111) and anchors gold nanoparticles deposited from solution to form dense, semiregular arrays. © 2007 American Chemical Society.

The effect of the bulk modification of the EPDM rubber compound on the adhesion performance with polyurethane coating (PU) was studied. Ethylene propylene diene monomer (EPDM) was bulk modified using maleated EPDM, polynorbornene (PNR) or different curatives to improve adhesion to polyurethane coating. The coating-rubber composite adhesion performance was examined by peel, crack and abrasion tests followed by microscopic investigation of fracture surfaces and their chemical nature. The adhesion between the coating and the rubber substrate was improved using maleated EPDM or PNR, as well as different curing systems. The crack stress for the delamination of the polyurethane coating from the flexible bulk-modified rubber surface follows the trend: maleated EPDM > PNR > different curing systems > control.