Determination of the size distribution of non-spherical nanoparticles by electric birefringence-based methods

The in situ determination of the size distribution of dispersed non-spherical nanoparticles is an essential characterization tool for the investigation and use of colloidal suspensions. In this work, we test a size characterization method based on the measurement of the transient behaviour of the birefringence induced in the dispersions by pulsed electric fields. The specific shape of such relaxations depends on the distribution of the rotational diffusion coefficient of the suspended particles. We analyse the measured transient birefringence with three approaches: the stretched-exponential, Watson-Jennings, and multiexponential methods. These are applied to six different types of rod-like and planar particles: PTFE rods, goethite needles, single- and double-walled carbon nanotubes, sodium montmorillonite particles and gibbsite platelets. The results are compared to electron microscopy and dynamic light scattering measurements. The methods here considered provide good or excellent results in all cases, proving that the analysis of the transient birefringence is a powerful tool to obtain complete size distributions of non-spherical particles in suspension.Financial support of this investigation by Junta de Andalucía, Spain (grant No. PE2012-FQM0694) and University of Granada (Program “Proyectos de investigación precompetitivos”) is gratefully acknowledged

Building Envelope as Surface

ArchitectureArchitectur

Perceptual Automaton

Perceptual Automaton (PA) challenges and disrupts human subjectivity. It attempts to reform architecture that has been for millennia centered on the authority of human subjectivity driven by the whims of architect-personalities. It more crucially interrogates the role of architecture as the material manifestation of human-specific dispositifs and provides a glimpse of posthuman ecology1 where architecture may transcend the vagaries of human body.OLD Public Buidin

Theatrical Performance as Experimental Architecture

This paper discusses by way of the authors' recent projects how improvised livedance performance, architectonic composition, and sensing technology converge and inform new opportunities in architectural experimentation. We first lay out the theoretical basis of technology in architectural experimentation in "new rationalities" of technologically augmented aesthetic work. We then briefly describe two projects, X-Change Room and RaumSubsTANZ and the motives behind them. X-Change Room deals with /non-verbal/ ambient display of information and interaction through envelope threshold. RaumSubsTANZ, a short interactive dance composition that highlights the ephemerality of architectural composition augmented by interaction devices. Through the two small projects we attempt to explore a specific technological milieu and reflect on the potentials and challenges of experimentation in architectural composition. The paper presents design methods and techniques that incorporate theories of perception and semiotics by way of an umbrella concept, "ambient displays" and interactive composition. Ultimately, we explore non-verbal communication and theatrical performance as architectural informant that augments semiosis and cognition that pertains to the role of technology at the intersection of primordial senses, cerebral technology, and place-making.OLD Public Buidin

ColorTracker

With the work-in-progress research project ColorTracker we explore color as a formal design tool. This project-based paper describes a novel software application that processes color composition of a place and transcribes the data into three-dimensional geometries for architectural design. The research comprises two parallel trajectories: a theoretical survey and the software application design. The theoretical survey presents the historical background of color. The project-based research seeks to develop digital methods and techniques that analyze the color compositions of the environment. Subsequently the objective is a novel application software for smart mobile devices in order to demonstrate the potentials of examining the color composition and chromatic parameters of a given environment and how it can contribute to the design.OLD Public Buidin

ColorTracker

With the work-in-progress research project ColorTracker we explore color as a formal design tool. This project-based paper describes a novel software application that processes color composition of a place and transcribes the data into three-dimensional geometries for architectural design. The research comprises two parallel trajectories: a theoretical survey and the software application design. The theoretical survey presents the historical background of color. The project-based research seeks to develop digital methods and techniques that analyze the color compositions of the environment. Subsequently the objective is a novel application software for smart mobile devices in order to demonstrate the potentials of examining the color composition and chromatic parameters of a given environment and how it can contribute to the design

Synthesis of New Polyether Ether Ketone Derivatives with Silver Binding Site and Coordination Compounds of Their Monomers with Different Silver Salts

Polyether ether ketone (PEEK) is a well-known polymer used for implants and devices, especially spinal ones. To overcome the biomaterial related infection risks, 4-4′-difluorobenzophenone, the famous PEEK monomer, was modified in order to introduce binding sites for silver ions, which are well known for their antimicrobial activity. The complexation of these new monomers with different silver salts was studied. Crystal structures of different intermediates were obtained with a linear coordination between two pyridine groups and the silver ions in all cases. The mechanical and thermal properties of different new polymers were characterized. The synthesized PEEKN5 polymers showed similar properties than the PEEK ones whereas the PEEKN7 polymers showed similar thermal properties but the mechanical properties are not as good as the ones of PEEK. To improve these properties, these polymers were complexed with silver nitrate in order to “cross-link” with silver ions. The presence of ionic silver in the polymer was then confirmed by thermogravimetric analysis (TGA) and X-ray powder diffraction (XRPD). Finally, a silver-based antimicrobial compound was successfully coated on the surface of PEEKN5