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In this work, two series of PDMS-modified poly(styrene-alt-maleic anhydride)s (PSMA) were prepared by the partial imidization of their anhydride groups with mono-functional, amine-terminated polydimethyl siloxanes (PDMS-NH2) with two different molecular weights. Subsequently, surfactant-free artificial latexes were prepared and characterized and applied onto cotton fabric. The water contact angle values of the coated cotton fabric indicate the formation of hydrophobic surfaces, with static contact angles varying from 119° to 142° depending on the PDMS loading and PDMS molecular weight. Coatings of the prepared copolymers on cotton fabric are highly durable, as shown by washing studies with a standard soap solution. The properties of these water-based surfactant-free latexes can be tuned easily by changing the composition of the polymers, i.e. mol% of imidization, ammonolysis and cross-linking. © 2013 Elsevier B.V. All rights reserved.

The effect of cerium-based corrosion inhibitors on the pH front between the alkaline cathode and acidic anode in corrosion cells has been studied. The cerium component of these inhibitors can affect the pH front since it precipitates in an alkaline environment as cerium hydroxide, which is important since the corrosion inhibition mechanism of the cerium component is a result of its deposition as a highly electrical resistive (passivation) layer on the cathode. It is studied whether the cerium can reach the cathode when fed into the corrosion cell from an external source after the onset of corrosion. To this end a simulation model was set up that includes the Poisson-Nernst-Planck theory to describe ion transport and the Frumkin-Butler-Volmer equation to describe charge transfer at the electrodes. In this model both the self-dissociation of water and the formation of cerium hydroxide are taken into account. To support our findings experimentally a corrosion cell consisting of an aluminum and copper electrode was used, in which the pH fronts were visualized using a pH-indicator. Two types of inhibitors were used; namely, highly soluble CeCl3 and sparsely soluble cerium dibutylphosphate, Ce(dbp)3. The results show that CeCl3 can reduce the size of the alkaline region and reach the cathode to form a passivation layer, whereas the solubility in case of Ce(dbp)3 is too low to supply sufficient amounts of trivalent cerium cations to penetrate the alkaline region. This behavior can be explained by the simulation results, which reveal a threshold for the corrosion inhibitor solubility below which no passivation of the cathode occurs. © 2013 Elsevier Ltd. All rights reserved.

In order to prevent a liquid epoxy cross-linker from premature, Arrhenius-law predicted, reaction with an acid-functional polyester resin, the liquid cross-linker has been physically separated from the resin by encapsulation while release is only possible by a temperature-controlled trigger. The glass transition temperature Tg of the polymeric encapsulant was used to trigger the softening of the polymeric capsule. Epoxidized linseed oil (ELO) cross-linker was encapsulated as 0.1 μm diameter droplets in 16 μm diameter microparticles (poly(N-vinyl)pyrrolidone) (PVP) by means of spray-drying. The resulting nano-composite microparticles were used to cross-link the acid functional polyester in a powder coating. It was found that below Tg the encapsulation considerably slows down the (premature) cross-link reaction. Beyond Tg also a slowdown was found but in this case it was caused by the mere presence of PVP rather than by the state of encapsulation of the cross-linker: PVP as a strong hydron bond acceptor slows down the reaction of epoxy with the acid groups of the polyester. In conclusion, the Tg of the encapsulant was successfully used as a temperature trigger for realizing the controlled release of a liquid reactant in a reactive polymer matrix. © 2012 Elsevier Ltd. All rights reserved.

An upscalable, self-aligned patterning technique for manufacturing high- performance, flexible organic thin-film transistors is presented. The structures are self-aligned using a single-step, multi-level hot embossing process. In combination with defect-free anodized aluminum oxide as a gate dielectric, transistors on foil with channel lengths down to 5 μm are realized with high reproducibility. Resulting on-off ratios of 4 × 10 6 and mobilities as high as 0.5 cm 2 V -1 s -1 are achieved, indicating a stable process with potential to large-area production with even much smaller structures.

In this article, we report the modification of poly(styrene-alt-maleic anhydride) (PSMA) with monofunctional amine-terminated poly(dimethyl siloxane) (PDMS-NH2) by thermal imidization, followed by the preparation and characterization of a surfactant-free artificial latex thereof and application of this latex onto cotton fabric. The imidization reaction was monitored by NMR and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. 1,2-Cyclohexyldicarboxylic anhydride was chosen as a model compound for the PSMA copolymer; this allowed a more detailed characterization by NMR and ATR-FTIR spectroscopy. After the PSMA/PDMS-NH2 imidization reached completion, a fraction of the anhydrides were ammonolyzed. In this way, a self-emulsifying latex with an average particle diameter of approximately 145 nm and a ζ potential of -56 mV was obtained. It was found that the PDMS-modified PSMA latex in which 30 mol% of the initial amount of anhydride groups were previously imidized by using PDMS-NH2 and a fraction of the anhydrides were ammonolyzed with 0.3 eq. of NH3 (PSMA30) was stable in the pH range 4-10. The water contact angle values of the latex-coated cotton textile fabric indicated a hydrophobized surface, with a static contact angle of 135.7°Â± 1.2°. The washing studies with a standard soap solution of the cotton samples with or without crosslinker showed that the crosslinked PSMA30 offered a good coating durability to the cotton. This waterborne resin based on surfactant-free latices displayed promising properties for coating applications and seemed to be very suitable for the hydrophobization of polar surfaces. © 2012 Wiley Periodicals, Inc.

Scratch resistant sol-gel metal oxide coatings typically require a thermal post-treatment step (curing process) at temperatures between 400 and 700 C. In this report, we demonstrate that the in situ generation of amines within sol-gel films facilitates the preparation of scratch resistant metal oxide coatings at a curing temperature of 250 C. A selected series of carbamates was added to sol-gel formulations and included in the resulting xerogel films. During the curing process, the carbamates decomposed to liberate primary amines. These catalysed the curing process, finally leading to scratch resistant metal oxide coatings at low cure temperature.

The increasing request for higher data speeds in the information and communication technology leads to continuously increasing performance of microprocessors. This has led to the introduction of optical data transmission as a replacement of electronic data transmission in most transmission applications longer than 10 meters. However, a need remains for optical data transmission for shorter distances inside the computer. This paper gives an overview of the Joint European project FIREFLY, in which new polymer based single mode waveguides are developed for integration with VCSELs, splitters and fibers that will be manufactured using multi-layer nanoimprint lithography (NIL). Innovative polymers, new applications of nano-technology, new methods for optical coupling between components, and the integration of all these new components are the technical ingredients of this ambitious project. New polymers: developments in siloxane based polymers will be discussed to reduce the optical loss at datacom and telecom wavelengths. These new polymers can already be processed using processes such as direct laser writing. New production processes: the implementation of the new polymers in multi-layer NIL will be assessed. The polymer cladding and core is structured at micrometer scale to create dense networks of single mode waveguides. The NIL process is a suitable technique for mass production. Integration: new concepts will be presented that will optimize the coupling of the components and reduce the optical losses that arise in coupling the lasers to waveguides, waveguides to fibres, and in 45° or 90° bends.

Scratch resistant sol-gel metal oxide coatings typically require a thermal post-treatment step (curing process) at temperatures between 400 and 700 C. In this report, we demonstrate that the in situ generation of amines within sol-gel films facilitates the preparation of scratch resistant metal oxide coatings at a curing temperature of 250 C. A selected series of carbamates was added to sol-gel formulations and included in the resulting xerogel films. During the curing process, the carbamates decomposed to liberate primary amines. These catalysed the curing process, finally leading to scratch resistant metal oxide coatings at low cure temperature.

The effect of cerium-based corrosion inhibitors on the pH front between the alkaline cathode and acidic anode in corrosion cells has been studied. The cerium component of these inhibitors can affect the pH front since it precipitates in an alkaline environment as cerium hydroxide, which is important since the corrosion inhibition mechanism of the cerium component is a result of its deposition as a highly electrical resistive (passivation) layer on the cathode. It is studied whether the cerium can reach the cathode when fed into the corrosion cell from an external source after the onset of corrosion. To this end a simulation model was set up that includes the Poisson-Nernst-Planck theory to describe ion transport and the Frumkin-Butler-Volmer equation to describe charge transfer at the electrodes. In this model both the self-dissociation of water and the formation of cerium hydroxide are taken into account. To support our findings experimentally a corrosion cell consisting of an aluminum and copper electrode was used, in which the pH fronts were visualized using a pH-indicator. Two types of inhibitors were used; namely, highly soluble CeCl3 and sparsely soluble cerium dibutylphosphate, Ce(dbp)3. The results show that CeCl3 can reduce the size of the alkaline region and reach the cathode to form a passivation layer, whereas the solubility in case of Ce(dbp)3 is too low to supply sufficient amounts of trivalent cerium cations to penetrate the alkaline region. This behavior can be explained by the simulation results, which reveal a threshold for the corrosion inhibitor solubility below which no passivation of the cathode occurs. © 2013 Elsevier Ltd. All rights reserved.

In this work, two series of PDMS-modified poly(styrene-alt-maleic anhydride)s (PSMA) were prepared by the partial imidization of their anhydride groups with mono-functional, amine-terminated polydimethyl siloxanes (PDMS-NH2) with two different molecular weights. Subsequently, surfactant-free artificial latexes were prepared and characterized and applied onto cotton fabric. The water contact angle values of the coated cotton fabric indicate the formation of hydrophobic surfaces, with static contact angles varying from 119° to 142° depending on the PDMS loading and PDMS molecular weight. Coatings of the prepared copolymers on cotton fabric are highly durable, as shown by washing studies with a standard soap solution. The properties of these water-based surfactant-free latexes can be tuned easily by changing the composition of the polymers, i.e. mol% of imidization, ammonolysis and cross-linking. © 2013 Elsevier B.V. All rights reserved.

In this contribution, we present the silica microencapsulation of hydrophilic compounds by templating Pickering emulsion droplets without contamination of the dispersed phase by either the catalyst or the silica precursor. This is accomplished by the use of an amphiphilic catalyst, which situates around the Pickering emulsion droplets and directs the reaction to the interface. Both the silica precursor and the amphiphilic catalyst are soluble in the oil phase and therefore initially do not reside in the hydrophilic microcapsule templates. The thickness of the capsules can be tuned by adjusting the amount of precursor. Thus, the permeability of the capsules can in principle be controlled. The possibility of tuning the permeability holds promise for a variety of applications of the microcapsules. Because of the straightforward synthesis method and minimized mixing of the core with contaminants, the technique is potentially suitable for the encapsulation of delicate matter including live organisms, drugs, enzymes or bacteria. © 2013 The Royal Society of Chemistry.

Exposure to water is a key issue in the performance of multilayer coatings. It may take place in different forms, i.e. as rainfall, dew and humidity variation. Consequently, coatings will experience time-dependent water activity fluctuations. In industrial practice, coatings are subjected to artificial water activity fluctuations in weathering tests. Little is known about the connection between these tests and the reality experience by a coating. This article presents a theoretical investigation of the response of multilayer coatings to water activity fluctuations. This investigation is performed on the basis of a validated model for water transport in hydrophilic base coat/hydrophobic top coat systems. The study aims to understand how permeability and sorption properties determine the overall coating response to fluctuations. It is concluded that present accelerated weathering tests do not mimic natural weathering due to the response time of the considered systems, which are insensitive to rapid fluctuations. © 2013 Elsevier B.V. © 2013 Elsevier B.V. All rights reserved.

A gelatinase-based device for fast detection of wound infection was developed. Collective gelatinolytic activity in infected wounds was 23 times higher (p ≤ 0.001) than in noninfected wounds and blisters according to the clinical and microbiological description of the wounds. Enzyme activities of critical wounds showed 12-fold elevated enzyme activities compared with noninfected wounds and blisters. Upon incubation of gelatin-based devices with infected wound fluids, an incubation time of 30 minutes led to a clearly visible dye release. A 32-fold color increase was measured after 60 minutes. Both matrix metalloproteinases and elastases contributed to collective gelatinolytic enzyme activity as shown by zymography and inhibition experiments. The metalloproteinase inhibitor 1,10-phenanthroline (targeting matrix metalloproteinases) and the serine protease inhibitor phenylmethlysulfonyl fluoride (targeting human neutrophil elastase) inhibited gelatinolytic activity in infected wound fluid samples by 11-37% and 60-95%, respectively. Staphylococcus aureus and Pseudomonas aeruginosa, both known for gelatinase production, were isolated in infected wound samples. © 2013 by the Wound Healing Society.

In this contribution, we present the silica microencapsulation of hydrophilic compounds by templating Pickering emulsion droplets without contamination of the dispersed phase by either the catalyst or the silica precursor. This is accomplished by the use of an amphiphilic catalyst, which situates around the Pickering emulsion droplets and directs the reaction to the interface. Both the silica precursor and the amphiphilic catalyst are soluble in the oil phase and therefore initially do not reside in the hydrophilic microcapsule templates. The thickness of the capsules can be tuned by adjusting the amount of precursor. Thus, the permeability of the capsules can in principle be controlled. The possibility of tuning the permeability holds promise for a variety of applications of the microcapsules. Because of the straightforward synthesis method and minimized mixing of the core with contaminants, the technique is potentially suitable for the encapsulation of delicate matter including live organisms, drugs, enzymes or bacteria. © 2013 The Royal Society of Chemistry.

The increasing request for higher data speeds in the information and communication technology leads to continuously increasing performance of microprocessors. This has led to the introduction of optical data transmission as a replacement of electronic data transmission in most transmission applications longer than 10 meters. However, a need remains for optical data transmission for shorter distances inside the computer. This paper gives an overview of the Joint European project FIREFLY, in which new polymer based single mode waveguides are developed for integration with VCSELs, splitters and fibers that will be manufactured using multi-layer nanoimprint lithography (NIL). Innovative polymers, new applications of nano-technology, new methods for optical coupling between components, and the integration of all these new components are the technical ingredients of this ambitious project. New polymers: developments in siloxane based polymers will be discussed to reduce the optical loss at datacom and telecom wavelengths. These new polymers can already be processed using processes such as direct laser writing. New production processes: the implementation of the new polymers in multi-layer NIL will be assessed. The polymer cladding and core is structured at micrometer scale to create dense networks of single mode waveguides. The NIL process is a suitable technique for mass production. Integration: new concepts will be presented that will optimize the coupling of the components and reduce the optical losses that arise in coupling the lasers to waveguides, waveguides to fibres, and in 45° or 90° bends.

In order to prevent a liquid epoxy cross-linker from premature, Arrhenius-law predicted, reaction with an acid-functional polyester resin, the liquid cross-linker has been physically separated from the resin by encapsulation while release is only possible by a temperature-controlled trigger. The glass transition temperature Tg of the polymeric encapsulant was used to trigger the softening of the polymeric capsule. Epoxidized linseed oil (ELO) cross-linker was encapsulated as 0.1 μm diameter droplets in 16 μm diameter microparticles (poly(N-vinyl)pyrrolidone) (PVP) by means of spray-drying. The resulting nano-composite microparticles were used to cross-link the acid functional polyester in a powder coating. It was found that below Tg the encapsulation considerably slows down the (premature) cross-link reaction. Beyond Tg also a slowdown was found but in this case it was caused by the mere presence of PVP rather than by the state of encapsulation of the cross-linker: PVP as a strong hydron bond acceptor slows down the reaction of epoxy with the acid groups of the polyester. In conclusion, the Tg of the encapsulant was successfully used as a temperature trigger for realizing the controlled release of a liquid reactant in a reactive polymer matrix. © 2012 Elsevier Ltd. All rights reserved.

Exposure to water is a key issue in the performance of multilayer coatings. It may take place in different forms, i.e. as rainfall, dew and humidity variation. Consequently, coatings will experience time-dependent water activity fluctuations. In industrial practice, coatings are subjected to artificial water activity fluctuations in weathering tests. Little is known about the connection between these tests and the reality experience by a coating. This article presents a theoretical investigation of the response of multilayer coatings to water activity fluctuations. This investigation is performed on the basis of a validated model for water transport in hydrophilic base coat/hydrophobic top coat systems. The study aims to understand how permeability and sorption properties determine the overall coating response to fluctuations. It is concluded that present accelerated weathering tests do not mimic natural weathering due to the response time of the considered systems, which are insensitive to rapid fluctuations. © 2013 Elsevier B.V. © 2013 Elsevier B.V. All rights reserved.

A gelatinase-based device for fast detection of wound infection was developed. Collective gelatinolytic activity in infected wounds was 23 times higher (p ≤ 0.001) than in noninfected wounds and blisters according to the clinical and microbiological description of the wounds. Enzyme activities of critical wounds showed 12-fold elevated enzyme activities compared with noninfected wounds and blisters. Upon incubation of gelatin-based devices with infected wound fluids, an incubation time of 30 minutes led to a clearly visible dye release. A 32-fold color increase was measured after 60 minutes. Both matrix metalloproteinases and elastases contributed to collective gelatinolytic enzyme activity as shown by zymography and inhibition experiments. The metalloproteinase inhibitor 1,10-phenanthroline (targeting matrix metalloproteinases) and the serine protease inhibitor phenylmethlysulfonyl fluoride (targeting human neutrophil elastase) inhibited gelatinolytic activity in infected wound fluid samples by 11-37% and 60-95%, respectively. Staphylococcus aureus and Pseudomonas aeruginosa, both known for gelatinase production, were isolated in infected wound samples. © 2013 by the Wound Healing Society.

Solar cookers supply clean and sustainable energy for cooking and so limit the use of wood or charcoal. A new type of solar cooker is developed with a hot plate. The hot plate offers comfortable access to the food under preparation. The hot plate opens up the opportunity to generate small amounts of electricity with the help of a thermo electric generator (TEG). The cooker uses a parabolic trough mirror, a Sidney Tube and a heat pipe to transport energy to the hot plate. The energy losses in the conversion steps and so the effectiveness of the whole system are verified with experiments. A comparison of the Tube Solar Cooker with a conventional parabolic solar cookers shows that the new solar cooker outperforms the state of the art on several aspects. The hot plate provides easy access to the pot without the risk of exposure to intense radiation. The high temperature of the hot plate increases the number of cooking techniques compared to conventional solar cookers. The avoidance of heat loss at elevated temperatures of the system is an important issue for further improvement. © 2012 IEEE.

We describe a water dispersed nano sensor cocktail based on InP/ZnS quantum dots (QDs) and atomic silver clusters with a bright and visible luminescence combined with optimized sensor functionalities for the water flooding process. The QDs and Ag nano sensors were tested in simulated reservoir conditions (high salinity, Ca2+, pH, high temperature, oil and solids). The nano sensors showed enhanced sensor functionalities towards pH, temperature, sub-terrain chemistry and reservoir solids like clay or calcium carbonate. Copyright 2012, Society of Petroleum Engineers.

We describe a water dispersed nano sensor cocktail based on InP/ZnS quantum dots (QDs) and atomic silver clusters with a bright and visible luminescence combined with optimized sensor functionalities for the water flooding process. The QDs and Ag nano sensors were tested in simulated reservoir conditions (high salinity, Ca2+, pH, high temperature, oil and solids). The nano sensors showed enhanced sensor functionalities towards pH, temperature, sub-terrain chemistry and reservoir solids like clay or calcium carbonate. Copyright 2012, Society of Petroleum Engineers.

In this article, we report the modification of poly(styrene-alt-maleic anhydride) (PSMA) with monofunctional amine-terminated poly(dimethyl siloxane) (PDMS-NH2) by thermal imidization, followed by the preparation and characterization of a surfactant-free artificial latex thereof and application of this latex onto cotton fabric. The imidization reaction was monitored by NMR and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. 1,2-Cyclohexyldicarboxylic anhydride was chosen as a model compound for the PSMA copolymer; this allowed a more detailed characterization by NMR and ATR-FTIR spectroscopy. After the PSMA/PDMS-NH2 imidization reached completion, a fraction of the anhydrides were ammonolyzed. In this way, a self-emulsifying latex with an average particle diameter of approximately 145 nm and a ζ potential of -56 mV was obtained. It was found that the PDMS-modified PSMA latex in which 30 mol% of the initial amount of anhydride groups were previously imidized by using PDMS-NH2 and a fraction of the anhydrides were ammonolyzed with 0.3 eq. of NH3 (PSMA30) was stable in the pH range 4-10. The water contact angle values of the latex-coated cotton textile fabric indicated a hydrophobized surface, with a static contact angle of 135.7°Â± 1.2°. The washing studies with a standard soap solution of the cotton samples with or without crosslinker showed that the crosslinked PSMA30 offered a good coating durability to the cotton. This waterborne resin based on surfactant-free latices displayed promising properties for coating applications and seemed to be very suitable for the hydrophobization of polar surfaces. © 2012 Wiley Periodicals, Inc.

Solar cookers supply clean and sustainable energy for cooking and so limit the use of wood or charcoal. A new type of solar cooker is developed with a hot plate. The hot plate offers comfortable access to the food under preparation. The hot plate opens up the opportunity to generate small amounts of electricity with the help of a thermo electric generator (TEG). The cooker uses a parabolic trough mirror, a Sidney Tube and a heat pipe to transport energy to the hot plate. The energy losses in the conversion steps and so the effectiveness of the whole system are verified with experiments. A comparison of the Tube Solar Cooker with a conventional parabolic solar cookers shows that the new solar cooker outperforms the state of the art on several aspects. The hot plate provides easy access to the pot without the risk of exposure to intense radiation. The high temperature of the hot plate increases the number of cooking techniques compared to conventional solar cookers. The avoidance of heat loss at elevated temperatures of the system is an important issue for further improvement. © 2012 IEEE.

This paper reports on manufacturing and characterization of an all-solid-state potentiometric sensor aimed at monitoring pH in dialysate or blood plasma for patients who undergo dialysis. The sensing polymer-based membrane, coated on top of the Au working electrodes, contains a polymer matrix - poly(vinyl chloride), octadecyl isonicotinate as sensor molecule, plasticizer bis(2-ethyl hexyl) sebacate, and potassium-tetrakis(4-chlorophenyl) borate. The sensor was first calibrated over a wider pH interval, i.e. 5.0 - 9.0, and then for a pH interval which overlaps with the physiological pH, i.e. 7.0 - 8.0, followed by tests in human blood plasma. The response of the sensor is linear over the studied pH range, with a lifetime of two weeks and an accuracy of ∼ 0.08 pH. The response of the sensor is influenced by the storage conditions, and tests with sensors stored dry prior to potential measurements in buffers show that the sensor needs a few hours to reach an equilibrium, as opposed to seconds for the sensors stored in pH buffers prior to data collection. Monitoring the potential for 18 h continuously shows that the sensor does not drift. Toxicity and leaching of components from the sensor membrane into the liquid environment around it were studied, and determined which components were selected to further develop the pH sensor. © 2011 IEEE.

This paper reports on manufacturing and characterization of an all-solid-state potentiometric sensor aimed at monitoring pH in dialysate or blood plasma for patients who undergo dialysis. The sensing polymer-based membrane, coated on top of the Au working electrodes, contains a polymer matrix - poly(vinyl chloride), octadecyl isonicotinate as sensor molecule, plasticizer bis(2-ethyl hexyl) sebacate, and potassium-tetrakis(4-chlorophenyl) borate. The sensor was first calibrated over a wider pH interval, i.e. 5.0 - 9.0, and then for a pH interval which overlaps with the physiological pH, i.e. 7.0 - 8.0, followed by tests in human blood plasma. The response of the sensor is linear over the studied pH range, with a lifetime of two weeks and an accuracy of ∼ 0.08 pH. The response of the sensor is influenced by the storage conditions, and tests with sensors stored dry prior to potential measurements in buffers show that the sensor needs a few hours to reach an equilibrium, as opposed to seconds for the sensors stored in pH buffers prior to data collection. Monitoring the potential for 18 h continuously shows that the sensor does not drift. Toxicity and leaching of components from the sensor membrane into the liquid environment around it were studied, and determined which components were selected to further develop the pH sensor. © 2011 IEEE.

In this paper we present the use of Photonic Crystals as chemical sensors. These 2D nanostructured sensors were prepared by nano-imprint lithography during which a nanostructure is transferred from a nickel template into a responsive polymer, that is be specifically tuned to interact with the chemical compound that must be detected. By creating a Photonic Crystal in a responsive polymer, the sensitivity of such a sensor can be greatly enhanced with respect to nanophotonic sensors that are only functionalized by a surface treatment. We have shown the functionality of an imprinted sensor by exposing the nanostructures to various liquids and vapours and monitor the change in reflected signal. Depending on the interactions and refractive index contrasts, the maximum wavelength of the reflected light can decrease (when exposed to toluene) or increase (when exposed to acetone). © 2011 Published by Elsevier Ltd.

TNO en VVVF zetten een stevige ambitie neer in de Roadmap Hernieuwbare Materialen. In 2030 is het merendeel van alle verven gebaseerd op biogrondstoffen. Dat is kort samengevat de ambitie die spreekt uit de Roadmap Biobased Coatings van TNO en VVVF. Een lastige, maar haalbare ambitie, vindt projectleider Corné Rentrop van TNO, want de verfbranche heeft een voorsprong op andere sectoren als het gaat om de toepassing van biobased grondstoffen. Er is de komende twintig jaar wél werk aan de winkel, waarschuwt VVVF-directeur Terpstra.

In this paper we present the use of Photonic Crystals as chemical sensors. These 2D nanostructured sensors were prepared by nano-imprint lithography during which a nanostructure is transferred from a nickel template into a responsive polymer, that is be specifically tuned to interact with the chemical compound that must be detected. By creating a Photonic Crystal in a responsive polymer, the sensitivity of such a sensor can be greatly enhanced with respect to nanophotonic sensors that are only functionalized by a surface treatment. We have shown the functionality of an imprinted sensor by exposing the nanostructures to various liquids and vapours and monitor the change in reflected signal. Depending on the interactions and refractive index contrasts, the maximum wavelength of the reflected light can decrease (when exposed to toluene) or increase (when exposed to acetone). © 2011 Published by Elsevier Ltd.

A reversible crosslinking mechanism enabling bonding and debonding of adhesives and coatings based on Diels-Alder chemistry is described. The Diels-Alder compounds form a covalently crosslinked network at low temperatures that break at elevated temperatures. As a result, the adhesive exhibits good solvent resistance, adhesion, and mechanical properties at temperatures of use, and additionally it can debond at elevated temperatures for optimal positioning, adjustments or total debonding. Upon cooling the covalent crosslinks are formed again and the properties of the original bond are re-obtained.The choice of crosslinker and binder material allows tailoring of the properties of the adhesive joint for different applications and processing conditions. At TNO, we have developed various Diels-Alder based binders for coatings and adhesives. This paper focuses on the design of a carrier adhesive for the semi-conductor industry. © 2010 Elsevier B.V. All rights reserved.

A reversible crosslinking mechanism enabling bonding and debonding of adhesives and coatings based on Diels-Alder chemistry is described. The Diels-Alder compounds form a covalently crosslinked network at low temperatures that break at elevated temperatures. As a result, the adhesive exhibits good solvent resistance, adhesion, and mechanical properties at temperatures of use, and additionally it can debond at elevated temperatures for optimal positioning, adjustments or total debonding. Upon cooling the covalent crosslinks are formed again and the properties of the original bond are re-obtained.The choice of crosslinker and binder material allows tailoring of the properties of the adhesive joint for different applications and processing conditions. At TNO, we have developed various Diels-Alder based binders for coatings and adhesives. This paper focuses on the design of a carrier adhesive for the semi-conductor industry. © 2010 Elsevier B.V. All rights reserved.

A distributed chemical sensor is developed by coating multiple Bragg gratings in a fibre with chemical selective responsive coatings. The optical response of the coated grating is optimised and the recoat process is very reproducible.

The effect of binding decamethyl-cyclopentasiloxane (silicone oil) to polymeric coating structures based on polyacrylic acid grafted with poly(ethylene glycol), Wacker 1100, Wacker 1650 or poly(dimethylsiloxane) is discussed and compared with the tribological test results for the water or dodecane lubricated situation. Friction was measured at low velocity sliding for a flat-on-flat configuration. A specific silicone rubber is used as counter surface based on a FIFA test to measure skin / surface friction in quality assessments of artificial turf. The results show promising combinations for which friction was reduced with 92% compared to dry conditions.

A study on the effect of a brush coating of polyacrylic 20 acid (PAA) grafted with poly(ethylene glycol) (PEG) (PAAQ1 g-PEG) on friction was done for a sliding system that involves silicone skin L7350: a silicone rubber used by the Fédération Internationale de Football Association (FIFA) for the determination of skin–surface friction in combination with artificial 25 grass. Friction experiments were carried out using a reciprocating flat-on-flat test setup with the selected brush coating and compared with PAA-coated and fluoroalkane-coated samples. The experiments were focused on the effect of water. Results for the coatings tested at dry conditions showed a coefficient 30 of friction above 1. Effective lubrication by water was able to reduce friction to a coefficient of friction below 0.01 at low sliding velocities. The results are currently used to further develop low-friction products for sliding interactions with human skin; for example, artificial grass and possibly medical textiles.

The success of nanomaterials in PV applications depends for a large part on their availability and procesability. Processes for large scale applications of these nanostructures are evaluated, with respect to antireflection and up/down conversion. © 2010 Optical Society of America.

The success of nanomaterials in PV applications depends for a large part on their availability and procesability. Processes for large scale applications of these nanostructures are evaluated, with respect to antireflection and up/down conversion. © 2010 Optical Society of America.

Dr Herman Lenting describes the latest developments in treating the growing problem of bedsores and explains how the LIDWINE team’s latest technologies could help to ease the pressure. The LIDWINE project seeks to develop new technologies which will prevent and alleviate the problems associated with Decubitus wounds.

In this work piezoelectric composite charge based sensors are developed, aimed at quasi-static pressure sensor or switch type applications. The use of piezoelectric composite materials allows for manufacturing robust devices which can easily be integrated with conventional polymer processing. Piezoelectric composites of lead zirconate titanate (PZT) and two types of polymers, polyamide-6 (PA6) and a liquid crystalline thermosetting polymer (LCT) were used to manufacture sensor devices. The behavior of the output signal of different types of sensors was studied with focus on both temperature dependence of the output signal and the drift of the signal with time. The properties of the PA6 based composites and devices are highly temperature dependent while the output signal of LCT based composites and devices has a very low temperature dependence and drift, even outperforming the PZT reference device. The temperature dependence of the output signal of the composite devices is dependent on the device configuration as well as the material properties, such as polymer permittivity. The drift of the signal is strongly dependent on the resistivity of the PZT-polymer composite material used in the sensor. © 2010 Elsevier B.V. All rights reserved.

A study on the effect of a brush coating of polyacrylic 20 acid (PAA) grafted with poly(ethylene glycol) (PEG) (PAAQ1 g-PEG) on friction was done for a sliding system that involves silicone skin L7350: a silicone rubber used by the Fédération Internationale de Football Association (FIFA) for the determination of skin–surface friction in combination with artificial 25 grass. Friction experiments were carried out using a reciprocating flat-on-flat test setup with the selected brush coating and compared with PAA-coated and fluoroalkane-coated samples. The experiments were focused on the effect of water. Results for the coatings tested at dry conditions showed a coefficient 30 of friction above 1. Effective lubrication by water was able to reduce friction to a coefficient of friction below 0.01 at low sliding velocities. The results are currently used to further develop low-friction products for sliding interactions with human skin; for example, artificial grass and possibly medical textiles.

In this work piezoelectric composite charge based sensors are developed, aimed at quasi-static pressure sensor or switch type applications. The use of piezoelectric composite materials allows for manufacturing robust devices which can easily be integrated with conventional polymer processing. Piezoelectric composites of lead zirconate titanate (PZT) and two types of polymers, polyamide-6 (PA6) and a liquid crystalline thermosetting polymer (LCT) were used to manufacture sensor devices. The behavior of the output signal of different types of sensors was studied with focus on both temperature dependence of the output signal and the drift of the signal with time. The properties of the PA6 based composites and devices are highly temperature dependent while the output signal of LCT based composites and devices has a very low temperature dependence and drift, even outperforming the PZT reference device. The temperature dependence of the output signal of the composite devices is dependent on the device configuration as well as the material properties, such as polymer permittivity. The drift of the signal is strongly dependent on the resistivity of the PZT-polymer composite material used in the sensor. © 2010 Elsevier B.V. All rights reserved.

Dr Herman Lenting describes the latest developments in treating the growing problem of bedsores and explains how the LIDWINE team’s latest technologies could help to ease the pressure. The LIDWINE project seeks to develop new technologies which will prevent and alleviate the problems associated with Decubitus wounds.