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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

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

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

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

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

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.

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

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.

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

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.

Ultrasonically initiated, in situ emulsion polymerization was used to prepare multiwalled carbon nanotube/polyaniline composites (MWNTs/PANI). Transmission electron microscopy (TEM) showed that the nanotubes were coated with a PANI layer, with the thickness of this coating varying with the content of carbon nanotubes and polymerization conditions. Whereas polyaniline/carbon nanotube composite particles prepared by the conventional stirring method have a highly structured, nodular morphology, ultrasonic initiation leads to long, thin, polymer-wrapped tubes. In the case of ultrasonically initiated in situ emulsion polymerization, Fourier transform infrared (FTIR) spectra suggested that site-selective interactions between the quinoid ring of the PANI and the MWNTs facilitate charge-transfer between the two components. In such composites, CNT improved the polymer properties, such as thermal stability, as determined by thermogravimetric analysis and conductivity measured using the four-probe method.