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Renz van Ee

Bio: Renz van Ee is an academic researcher from Netherlands Organisation for Applied Scientific Research. The author has contributed to research in topics: Nanoparticle & Particle size. The author has an hindex of 4, co-authored 6 publications receiving 70 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, a percolated network of Ag-modified cellulose nanocrystals (CNCs) is formed upon solvent evaporation, and the resulting coatings are electrically conductive with an unprecedented high conductivity of 2.9 × 104 S cm−1.
Abstract: For the preparation of electrically conductive composites, various combinations of cellulose and conducting materials such as polymers, metals, metal oxides and carbon have been reported. The conductivity of these cellulose composites reported to date ranges from 10−6 to 103 S cm−1. Cellulose nanocrystals (CNCs) are excellent building blocks for the production of high added value coatings. The essential process steps for preparing such coatings, i.e. surface modification of CNCs dispersed in water and/or alcohol followed by application of the dispersion to substrate samples using dip coating, are low cost and easily scalable. Here, we present coatings consisting of Ag modified CNCs that form a percolated network upon solvent evaporation. After photonic sintering, the resulting coatings are electrically conductive with an unprecedented high conductivity of 2.9 × 104 S cm−1. Furthermore, we report the first colloidal synthesis that yields CNCs with a high degree of Ag coverage on the surface, which is a prerequisite for obtaining coatings with high electrical conductivity.

27 citations

Journal ArticleDOI
TL;DR: In this article, a set-up that allows accurate measurements in real-time on flowing dispersions using a dynamic light scattering (DLS) technique based on modulated 3D cross-correlation is presented.
Abstract: To tailor the properties of nanoparticles and nanocomposites, precise control over particle size is of vital importance. Real-time monitoring of particle size during bottom-up synthesis in liquids would allow a detailed study of particle nucleation and growth, which provides valuable insights in the mechanism of formation of the nanoparticles. Furthermore, it facilitates a rational scale-up, and would enable adequate intervention in the production process of nanoparticle dispersions to minimize the number of off-spec batches. Since real-time monitoring requires particle size measurements on dispersions in flow, conventional dynamic light scattering (DLS) techniques are not suited: they rely on single scattering and measure the Brownian motion of particles dispersed in a liquid. Here, we present a set-up that allows accurate measurements in real-time on flowing dispersions using a DLS technique based on modulated 3D cross-correlation. This technique uses two simultaneous light scattering experiments performed at the same scattering vector on the same sample volume in order to extract only the single scattering information common to both. We connected the reactor to a flow-cell in the DLS equipment using a tailor-made analysis loop, and successfully demonstrated the complete set-up through monitoring of the size of spherical silica nanoparticles during Stober synthesis in a water-alcohol mixture starting from the molecular precursor tetraethyl orthosilicate.

23 citations

Journal ArticleDOI
TL;DR: In this paper, the authors demonstrate that randompacking of silicated CNCs can also yield materials with interesting optical properties, i.e., highly porous,ultra-low refractive index coatings.

18 citations

Proceedings ArticleDOI
TL;DR: In this article, the authors describe experimental measurement results for photonic crystal sensor devices which have been functionalized for gas sensing applications, and discuss details of chemical functionalization of the PC sensor.
Abstract: This paper describes experimental measurement results for photonic crystal sensor devices which have been functionalized for gas sensing applications. The sensor consists of a two dimensional photonic crystal etched into a slab waveguide having a refractive index of 1.7-1.9. Test devices were fabricated from SiON material on silicon/ silicon dioxide platform, and also in polymer materials on silicon platform. The inorganic photonic crystals were made using direct write electron-beam lithography and reactive ion etching. The polymeric devices were made by nano-imprint lithography using the SiON structure as the imprint master. The high refractive index polymer was composed of a TiO 2- UV resin nanocomposite having a nanoparticle fraction between 50 and 60 wt%. This resulted in a tunable refractive index between 1.7 and 1.85. Devices were functionalized for gas sensing applications by coating the surface with a chemical receptor. This responsive layer reacts with the target gas and changes its refractive index. This change causes the angle of out-coupling to change slightly. In this paper we report successful detection of formaldehyde in air at sub ppm levels, and discuss details of chemical functionalization of the PC sensor. cop. 2014 SPIE.

5 citations

Journal ArticleDOI
TL;DR: In this article, an ultrasound nanoparticle sizer (UNPS) is used for real-time monitoring of particle size and concentration during bottom-up synthesis in liquids, which provides valuable insights into the formation of nanoparticles that can be used for process optimization and scale up.
Abstract: Both in design and production of nanoparticles and nanocomposites it is of vital importance to have information about their size and concentration. During the formation of nanoparticles, real-time monitoring of particle size and concentration during bottom-up synthesis in liquids allows for a detailed study of nucleation and growth. This provides valuable insights into the formation of nanoparticles that can be used for process optimization and scale up. In the production of nanoparticles, real-time monitoring enables intervention to minimize the number of off-spec batches. In this paper we will qualify an ultrasound nanoparticle sizer (UNPS) as a real-time monitor for the growth of nanoparticles (or sub-micro particles) in the 100 nm-1 μm range. Nanoparticles affect the speed and attenuation of ultrasonic waves in the dispersion. The size of the change depends, amongst other things, on the size and concentration of the nanoparticles. This dependency is used in the UNPS method. The qualification of the UNPS was undertaken in two successful experiments. The first experiment consisted of static measurements on commercially available silica particles, and the second experiment was real-time monitoring of the size and concentration during the growth of silica nanoparticles in Stober synthesis in a water-alcohol mixture starting from the molecular precursor tetraethyl orthosilicate. The results of the UNPS were verified by measurements of a dynamic light scattering device and a transmission electron microscope. © 2018 by the authors.

3 citations


Cited by
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Journal ArticleDOI
TL;DR: This work discusses the main areas of nanocellulose research: photonics, films and foams, surface modifications, nanocomposites, and medical devices.

659 citations

Journal ArticleDOI
TL;DR: In this article, different conductive metal nanomaterials are introduced, and the challenges facing methods of thin film deposition and applications of thin films as conductive coatings are investigated, as well as the application of conductive materials in thin-film applications.
Abstract: With ever-increasing demand for lightweight, small, and portable devices, the rate of production of electronic and optoelectronic devices is constantly increasing, and alternatives to the current heavy, voluminous, fragile, conductive and transparent materials will inevitably be needed in the future. Conductive metal nanomaterials (such as silver, gold, copper, zinc oxide, aluminum, and tin) and carbon-based conductive materials (carbon nanotubes and graphene) exhibit great promise as alternatives to conventional conductive materials. Successfully incorporating conductive nanomaterials into thin films would combine their excellent electrical and optical properties with versatile mechanical characteristics superior to those of conventional conductive materials. In this review, the different conductive metal nanomaterials are introduced, and the challenges facing methods of thin film deposition and applications of thin films as conductive coatings are investigated.

139 citations

Journal ArticleDOI
17 May 2016-Langmuir
TL;DR: This work discusses the four routes for introducing porosity in quarter-wave coatings through the use of colloidal particles, which have the highest potential for application and addresses the remaining challenges in the field of ARCs.
Abstract: Antireflective coatings (ARCs) are applied to reduce surface reflections. We review coatings that reduce the reflection of the surface of the transparent substrates float glass, polyethylene terephthalate, poly(methyl methacrylate), and polycarbonate. Three main coating concepts exist to lower the reflection at the interface of a transparent substrate and air: multilayer interference coatings, graded index coatings, and quarter-wave coatings. We introduce and discuss these three concepts, and zoom in on porous quarter-wave coatings comprising colloidal particles. We extensively discuss the four routes for introducing porosity in quarter-wave coatings through the use of colloidal particles, which have the highest potential for application: (1) packing of dense nanospheres, (2) integration of voids through hollow nanospheres, (3) integration of voids through sacrificial particle templates, and (4) packing of nonspherical nanoparticles. Finally, we address the remaining challenges in the field of ARCs, and elaborate on potential strategies for future research in this area.

97 citations

Journal ArticleDOI
TL;DR: In this paper, a study aimed at identifying industry 4.0 neologisms and illustrating the convergence of 12 disruptive technologies including 3D printing, artificial intelligence, augmented reality, big data, blockchain, cloud computing, drones, Internet of Things, nanotechnology, robotics, simulation, and synthetic biology in agriculture, healthcare, and logistics industries was illustrated.
Abstract: Very well into the dawn of the fourth industrial revolution (industry 4.0), humankind can hardly distinguish between what is artificial and what is natural (e.g., man-made virus and natural virus). Thus, the level of discombobulation among people, companies, or countries is indeed unprecedented. The fact that industry 4.0 is explosively disrupting or retrofitting each and every industrial sector makes industry 4.0 the famous buzzword amongst researchers today. However, the insight of industry 4.0 disruption into the industrial sectors remains ill-defined in both academic and nonacademic literature. The present study aimed at identifying industry 4.0 neologisms, understanding the industry 4.0 disruption and illustrating the disruptive technology convergence in the major industrial sectors. A total of 99 neologisms of industry 4.0 were identified. Industry 4.0 disruption in the education industry (education 4.0), energy industry (energy 4.0), agriculture industry (agriculture 4.0), healthcare industry (healthcare 4.0), and logistics industry (logistics 4.0) was described. The convergence of 12 disruptive technologies including 3D printing, artificial intelligence, augmented reality, big data, blockchain, cloud computing, drones, Internet of Things, nanotechnology, robotics, simulation, and synthetic biology in agriculture, healthcare, and logistics industries was illustrated. The study divulged the need for extensive research to expand the application areas of the disruptive technologies in the industrial sectors.

77 citations