Day 3 :
Keynote Forum
Dr. Borja Sepulveda
ICN2, Spain
Keynote: Multifunctional magneto-plasmonic nanostructures for nanotherapies and imaging
Biography:
Borja Sepulveda received his PhD degree in Physics from the Complutense University of Madrid in 2005. His Post-graduate research was carried out at the Microelectronics Institute of Madrid (CSIC). In 2006 he started a two years Postoctoral stay at the Bionanophotonics and Bioimaging group in Chalmers University of Technology (Göteborg, Sweden). In 2008 he joined the Catalan Institute of Nanoscience and Nanotechnology (ICN2) of Barcelona as Research Fellow, where he got a Ramon y Cajal grant in 2009. From 2012, he holds a permanent research position at the ICN2. During his scientific career, he has acquired a highly multidisciplinary experience, focused on the development of photonic and magnetic nanostructures for biomedical and environmental control applications. In particular, he has acquired experience in very diverse fields such as: photonics and nano-photonics, magneto-optics and magneto-plasmonics, nano-fabrication, surface chemistry and microfluidics. He is co-author of more than 50 publications, and the first author of three patents.
Abstract:
Magnetic nanostructures have demonstrated their enormous potential as biomedical nanodevices with both therapeutic and diagnostic activities. One of the most promising application is their use as heat mediators for magnetic fluid hyperthermia, where the nanostructures dissipate heat in the presence of alternating magnetic fields. Similarly, plasmonic nanostructures also exhibit encouraging properties in plasmonic absorption hyperthermia, where plasmonic nanostructures generate heat when irradiated with laser light. Thus, combining both properties in a single entity, i.e., magnetoplasmonic nanostructures, may open new avenues in the design of biomedical nanoplatfoms. Here we present two approaches for the design of magnetoplasmonic nanostructures for biomedical applications using bottom-up and top-down approaches. Magnetic-plasmonic nanoparticles of different sizes and morphologies based on Fe3O4 and Au were synthesized by thermal decomposition (bottom-up). This method allows the synthesis of particles with high crystallinity, defined shape and narrow size distribution. Colloidal lithography (top-down) was used to develop magnetoplasmonic nanodomes based on Au and Fe. Both types of structures exhibit appealing magnetic properties at room temperature and clear plasmonic resonances. Hyperthermia measurements show that these nanostructures can be used as heat mediators in magnetic and plasmonic modes. Moreover, the combination or magnetic and plasmonic moieties confers the system additional functionalities like the capability to act as contrast agent for X-Ray Computed Tomography and optical imaging (Au) or as magnetic resonance imaging, MRI (Fe and Fe3O4). This combination of properties paves the way to use these hybrid nanostructures as potential theranostic (therapy-diagnostic) agents.
Keynote Forum
Jordi Arbiol
ICREA & Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC & BIST, Spain
Keynote: Free-standing nanostructures at atomic scale: from growth mechanisms to local properties at the nanoscale
Biography:
Jordi Arbiol graduated in Physics at Universitat de Barcelona (UB) in 1997, where he also obtained his PhD (European Doctorate and PhD Extraordinary Award) in 2001 in the field of transmission electron microscopy (TEM) applied to nanostructured materials. He was Assistant Professor at UB. From 2009 to 2015, he was Group Leader at Institut de Ciència de Materials de Barcelona, ICMAB-CSIC. He is President of the Spanish Microscopy Society (SME), was the Vice-President from 2013 to 2017. Since 2015 he is the Leader of the Group of Advanced Electron Nanoscopy at Institut Català de Nanociència i Nanotecnologia (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST). He has been awarded with the 2014 EMS Outstanding Paper Award, the EU40 Materials Prize 2014 (E-MRS), listed in the Top 40 under 40 Power List (2014) by The Analytical Scientist and the PhD Extraordinary Award in 2001 (UB).
Abstract:
Technology at the nanoscale has become one of the main challenges in science as new physical effects appear and can be modulated at will. Superconductors, materials for spintronics, electronics, optoelectronics, sensing, energy applications and new generations of functionalized materials are taking advantage of the low dimensionality, improving their properties and opening a new range of applications. As developments in materials science are pushing to the size limits of physics and chemistry, there is a critical need for understanding the origin of these unique physical properties (optical and electronic) and relate them to the changes originated at the atomic scale, e.g.: linked to changes in (electronic) structure of the material. In the present work, I will show how combining advanced electron microscopy imaging with electron spectroscopy, as well as cathodoluminescence in an aberration corrected STEM will allow us to probe the elemental composition and electronic structure simultaneously with the optical properties in unprecedented spatial detail. The talk will focus on several examples in advanced nanomaterials for optical, plasmonic and energy applications. In this way the latest results obtained by my group on direct Visualizing and modeling materials at atomic scale will help to understand their growth mechanisms (sometimes complex) and also correlate their physical properties (electronic and photonic) at sub-nanometer with their atomic scale structure. The examples will cover a wide range of nanomaterials: quantum structures self-assembled in a nanowire: quantum wires (1D) and quantum dots (0D) and other complex nanowire-like morphologies for photonic and energy applications (LEDs, lasers, quantum computing, single photon emitters, water splitting cells, batteries), nanomembranes and 2D sheets; as well as metal multiwall nanoboxes and nanoframes for 3D plasmonics.
Keynote Forum
Heiko Jacobs
Nanotechnology group TU Iimenau, Germany
Keynote: Localized Programmable Gas Phase Electrodeposition; A new Transport Process with Applications Ranging from the Deposition of Functional Nanostructures to the Collection and Identification of Airborne Species for Sensing Applications
Biography:
Heiko O. Jacobs has his expertise in nanotechnology and heterogeneous integration of electronics over different length scales. His new deposition and assembling strategies established new integration strategies in solid, liquid and gas phase, which create new pathways for improving assembly techniques. He has built the ideas for this research during his Postdoc time at Whitesides in Harvard (99-01) and developed them during his time as a professor in Minnesota. Nowadays, these ideas are used in applications based on Nanoxerography, Gas Phase Electrodeposition and Fluidic Self-Assembly.
Abstract:
This talk describes a recently discovered transport approach that enables the localized deposition and collection of microscopic, nanoscopic, and molecular sized particles at high rates and in 3D. The localized gas phase deposition and collection process is based on the interplay of high mobility gas ions and lower mobility nanoparticles and molecules in the presence of a pre-patterned substrate. The first half of the talk will discuss an application where the approach is used to grow functional 3D nanostructures which are composed of metallic and semiconducting particles, including nanostructured electrodes for bulk heterojunction photovoltaics, multifunctional nanomaterial based sensors, plasmonic structures, and nanowire interconnects.[1,2] The second half will discuss an extension to an application in the field of sensing of airborn analytes where the method is applied to locally collect molecules at collection rates that exceed diffusion-only-transport.[3,4,5] Specifically we will demonstrate localized collection of analytes over a wide range of molecular weights ranging from 3×10^17 to 1×10^2 Daltons, including (i) microscopic analyte particles, (ii) inorganic nanoparticles, all the way down to (iii) small organic molecules. Implications: In all cases we find that the collection rate is several orders of magnitudes higher than in the case where our advanced collection schemes is turned off and where collection is driven by diffusion only. The collection scheme is integrated on an existing surface-enhanced Raman spectroscopy based sensor. In terms of response time, the process is able to detect analytes at 9 parts per million within 1 second. As a comparison, 1 hour is required to reach the same signal level when diffusion-only-transport is used.
Keynote Forum
Valery Pavlov
CIC BiomaGUNE, Spain
Keynote: Effect of biocatalytic reactions on growth of semiconductor nanoparticles: Application to biosensing
Biography:
V. Pavlov obtained his PhD degree in Chemical Engineering in January 2005 from the University Rovira I Virgili (Spain). He worked in the Hebrew University of Jerusalem (Israel) in the group of professor Itamar Willner as a postdoctoral researcher. Since October he continued his postdoctoral study at the Chemistry Department of the University of Heidelberg (Germany). In February 2007 he joined the new research institute CIC BiomaGUNE in San Sebastian as a group leader. His research interests include enzymatic generation of metal and semiconductor nanoparticles, production of new recombinant mutated enzymes, and optical bioanalytical assays.
Abstract:
Our laboratory discovered for the first time that products of enzymatic reactions are able to modulate growth of semiconductor fluorescent CdS nanoparticles (NPs) grown in situ. Emission spectra of these NPs depend on their size and capping agents which stabilize them in aqueous solutions. We found out experimental conditions under which the growth of CdS NPs is very rapid and takes 10 min or less. The biocatalytic growth of CdS NPs has been applied to optical determination of enzymatic activities of enzymes such as acetylcholine esterase,1 horseradish peroxidase,2 glucose oxidase3 etc. We also reported novel sensitive selective electrochemical assays based on generation of CdS NPs in situ which is modulated by affinity interactions and oxidative activity of metal ions. For example, our immunoassay employs antibody-alkaline phosphatase conjugate which catalyzes generation of CdS detected with disposable carbon electrodes premodified with the electroconductive polymer Os-PVP.4 We demonstrated a new electrochemical assay employing microbead linked enzymatic generation of CdS QDs (Microbead QD-ELISA)5 for cancer marker superoxide dismutase. In the presence of this analyte, CdS NPs were formed on the surface of microbeads modified with antibodies for superoxide dismutase (Fugure 1). Formed in situ CdS NPs were followed with fluorescence spectroscopy, microscopy, and square-wave voltammetry. Our latest assays use cysteine (CSH) which stabilizes CdS NPs growing during the biorecognition event in aqueous buffered solutions. Oxidation of CSH with hydrogen peroxide (H2O2) results in formation of cystine (CSSC) which does not stabilize CdS NPs. A number of chemical and biochemical reactions involving copper ions, glucose6 and methanol yield hydrogen peroxide, modulating the quantity of CdS NPs produced in situ.
- Young Researchers Forum
Location: Frankfurt
Chair
Borja Sepulveda
ICN2, Spain
Session Introduction
Alireza Kavand
Université de Strasbourg, CNRS, France
Title: Preparation of ultrasmall monodisperse upconversion nanocrystals and their size control using an intensified heat treatment process
Biography:
Alireza Kavand obtained his BS degree in Chemistry from the University of Zanjan and his Master’s degree in Polymer Chemistry from the University of Tehran (Iran). Currently, he is a member of the CMP group as PhD student at Institute Charles Sadron (France). His current research interests are polymer synthesis based on peptide, microfluidic system and upconversion nanoparticles for drug delivery application.
Abstract:
This presentation will show a simple and efficient method to produce ultrasmall hexagonal-phase upconversion nanocrystals (UCNCs) to be used as luminescent labels for biomedical applications. Preparation of nanosized hexagonal-phase UCNCs is a great challenge but many methods have been reported to synthesize efficiently UCNCs in the size range 15 to 50 nm. One of the easiest and most convenient approach is the co-precipitation method that involves nucleation (precipitation step) and growth of particles (heat treatment step). In the case of the synthesis of ultrasmall UCNCs (sub-10 nm), some researchers have used lanthanide dopant while others have changed some operating parameters to achieve a rapid nucleation rate such as different mixed ligands, shorten heat treatment time etc. But these strategies induced the undesired effect of increasing the energy barrier between cubic phase and hexagonal phases. Herein we report on a modified heat treatment procedure to achieve monodisperse ultrasmall UCNCs in good yields. We used stainless steel microtubes with different inner diameters and lengths for the heat treatment step and compared the results with the standard batch method using a simple flask. Microtubes filled with the UCNCS nuclei solution were placed in a thermoregulated oven at (300°C) for 120 min. It was found that the sizes and properties of UCNCs were influenced by the type of heat treatment device (flask or microtube) which was never reported until now. Nanoparticles produced with the bigger tube (ID: 4083 µm) showed ultrasmall size (around 7 nm) and narrower size distribution (PDI 0.2), while the nanoparticles obtained using a smaller tube (ID: 876 µm) or produced with the flask showed bigger sizes about 700 nm and 50 nm respectively (PDI: 0.5 and 0.3). The length of the microtube was found not to affect significantly the particle size which is an important factor for future scale up. However, for the same formulation, the volume of the flask (5 and 21 mL) did affect quite noticeably the size of the UCNCs obtained (50 and 190 nm respectively). The presentation will aim also at introducing our latest results regarding the continuous-flow heat treatment in microtubes.
Jie Sun
Centre of Electrochemical Surface Technology GmbH (CEST), Austria
Title: Antibacterial surface modification of Ti based material for implants
Biography:
Jie Sun is a PhD student at the Technical University of Vienna working at the Institute of Chemical Technologies and Analytics. He obtained Master of Science degree in Chemistry. His research focuses on electrochemical surface modification of medical implants based on titanium.
Abstract:
Statement of the Problem: Titanium and its alloys are widely used as implant material due to their tensile strength, flexibility, corrosion resistance, high hemo- and biocompatibility. A defined surface nanotopology offers guidance of the implant vs. cell interaction and at the same time gives opportunities for further modifications; promoting the bone growth, providing nano-containers for antibacterial agents, etc.
Methodology & Theoretical Orientation: Different strategies are applied to modify titanium and titanium alloy implant material, aiming at better antibacterial properties and biocompatibility. Pure titanium and titanium alloy Ti7Al are anodized to create titanium nanotubes. Subsequently, the nanotubes are annealed in order to transform the obtained TiO2 into TiO2 anatase phase (XRD and Raman spectroscopy). In a following step, the surface is electrochemically modified.
Findings: It is shown that addition of phosphate to the ethylene glycol based bath has certain influence on the titanium nanotubes topology. Nanotubes (pTNT) with a diameter of 100 nm are produced in ethylene glycol containing fluoride and phosphate, as additives. By electrochemical deposition the pTNT are uniformly filled with Se and coated with Cu2Se or Ag2Se. The composition and the structure of the layers are confirmed by EDX, FIB, SEM and XRD. A positive effect of Se on the nucleation of hydroxyapatite (HAp) during the electrodeposition was established. The quality and adhesion of the HAp coating is found to strongly depend on the structure of the substrate, the pH value of the bath, the applied voltage and the temperature.
Conclusion & Significance: Uniform and circular pTNT with a diameter of 100 nm are produced and regularly filled with antibacterial agent. A bone like substance HAp with nano-crystalline structure is successfully electrodeposited on the pTNT surface. The as-prepared coatings will be further examined in medical in-vitro and in-vivo experiments and undergo clinical tests.
Biography:
Torsten Walbert has his expertise in template-assisted electroless metal plating. After he received his Master’s degree in Chemistry from Technische Universität Darmstadt, he decided to change disciplines within the university and started a PhD in the field of Materials Science. Therein, he works on the template-assisted fabrication of complex metal nanostructures for the application as catalyst in fuel cells or as electrode in battery systems. He presented his work at scientific conferences in Lisbon (SMMIB) as well as Lausanne (Junior Euromat) where he received the award for best poster presentation in the area of functional materials. This template-assisted approach represents a highly flexible and promising method, enabling the independent modification of numerous material parameters.
Abstract:
In recent years, unsupported noble-metal nanocatalysts received increased attention in consideration of various potential application fields. However, due to high material costs and structure-dependency of catalytic performance, a precise control of nanostructure fabrication is required. A highly suitable and scalable approach is represented by template-assisted synthesis methods, which enable the direct adjustment of structural parameters and thus facilitate tailoring the catalytic performance. One of the most flexible routes implies the employment of ion track-etched polymer membranes. Therefore, a certain polymer (e.g. PC, PET, PI) is irradiated with swift heavy ions, leading to the formation of latent damage tracks. Selective etching of the tracks produces high aspect ratio nanochannels with adjustable dimensions. These can be used as templates for the fabrication of nanotubes. The tubes are formed by redox-chemical deposition of the desired material onto the pore walls. After dissolution of the template, freestanding nanotubes are obtained. Depending on the angle of incidence and the ion fluence during irradiation, even interconnected nanotubes can be generated, resulting in mechanically stabilized nanotube networks (NTNWs). As an example, the synthesis of Pt NTNWs is shown in Figure 1. Due to the template-assisted approach, nanotube composition, size and morphology can be easily controlled and tailored regarding potential applications. In case of methanol oxidation reaction (MOR), a partially porous Pt NTNW is applied as catalyst, showing increased durability as well as mass activity compared to a commercial Pt nanoparticle catalyst. Thus, the use of 3D nanostructured materials can increase specific surface area while retaining structural stability, resulting in a better catalytic performance. Besides, utilization as a support with high surface area and thermal, chemical as well as mechanical stability, e.g. as current collector in battery systems, is feasible.
Pegah Esmaeilzadeh
Martin Luther University Halle Wittenberg, Germany
Title: A Smart Cell Carrier Nanosystem made from Thiolated Polysaccharides
Biography:
Pegah Esmaeilzadeh’s M.S. researches in the field of synthesis and characterization of single-walled natural protein nanotubes, and their byproduct architectures such as protein nanofibers, nanospheres, and nanoparticles have been successfully developed in nanotechnology section of RIPI of Tehran (Research Institute of Petroleum Industry). She was also active in different research projects on ZnO quantum dots as novel antibacterial, antifungal, or anticancer drugs. She is currently PhD student in institute of pharmacy in Martin Luther University Halle Wittenberg in Germany, and receiving new experiences in medical nanocoatings/interfaces/thin films and particularly cell studies.
Abstract:
Mimicking the functions of macromolecules, nanotechnology approaches have made great efforts to synthesize adaptive and stimuli-responsive biointerfaces for new therapeutic functions in medical implants or supporters for tissue growth/regeneration. Here, we introduce a switchable medical coating system made of 5 bilayers of thiolated- chitosan and thiolated-chondroitin sulfate biopolymers. This synthesized foundation were structured by bottom-up layer by layer technique. The idea of this study is a new cyclical methodology that enables forward and reverse surface reconstructions of cell-adhesive properties of multilayers by switching from oxidation to reduction direction (Oxi-to- Re) [figure 1] and in opposite from reduction to oxidation direction (Re-to-Oxi). While the rearrangements of surface charge, content of free thiol-groups and wettability characteristics after cyclical manipulations were tested by zeta potential, UV–Vis, and water contact angle techniques, monitoring the human dermal fibroblast cell– coating interactions confirms the smart multifunctionality of this novel coating model towards switchable protein adsorption/desorption and cell attachment/detachment rules.
Shivaji M Sonawane
Savitribai Phule Pune University, India
Title: Electrochemical Synthesis of ZnTe and Cu-ZnTe thin films for low resistive ohmic back contact for CdS/CdTe solar cells.
Biography:
Shivaji M Sonawane is currently an Assistant Professor of Physics at B J S Arts Science and Commerce College in Pune, India. He is working as Research Fellow in Department of Physics, Savitribai Phule Pune University for pursuing his PhD. He has published more than 15 papers in reputed journals and presented at international conferences. His main research interests are development of semiconductor thin films for CdS/CdTe solar cell.
Abstract:
CdTe thin film photovoltaic solar cells are amongst the promising technology for large scale solar electricity production. ZnTe are intensively studied as an interface layer for CdTe absorber in CdS/CdTe thin film photovoltaic devices. ZnTe is direct band gap; P-type semiconductor with high absorption coefficient of the order of 104 cm-1 is suitable for solar cell development. It can be used as a low resistive ohmic contact to CdS/CdTe or tandem solar cell application. ZnTe and Cu-ZnTe thin film have been electrochemically synthesized on to fluorine-doped tin oxide coated glass substrates using three electrode systems containing Ag/AgCl, graphite and FTO as reference, counter and working electrode respectively was used to deposit the thin films. The aqueous electrolytic solution consist of 0.5M TeO2, 0.2M ZnSO4, and 0.1M Na3C6H5O7:2H2O, 0.1MC6H8O7:H2O and 0.1mMCuSO4 with PH 2.5 at room temperature was used. The reaction mechanism is studied in the cyclic voltammetry to identify the deposition potentials of ZnTe and Cu-ZnTe.The potential was optimized in the range -0.9 to -1.1 V vs. Ag/AgCl reference electrode. The effect of depositon potential on the structural properties was studied by using X-ray diffraction. The X-ray diffraction result reveled cubic crystal structure of ZnTe with preferential (111) orientation with cubic structure. The surface morphology and film composition were analyzed by means of Scanning Electron Microscopy (SEM) and Energy Dispersive Analysis of X- Rays (EDAX). The optical absorption measurement has been analyzed for the band gap determination of deposited layers about 2.26 eV by UV-Visible spectroscopy. The drastic change in resistivity has been observed due to incorporation of copper probably due to the diffusion of Cu in to grain boundaries.
Ganesh R. Bhand
Savitribai Phule Pune University, India
Title: Investigation of doping of CdSe QDs in organic semiconductor for solar cell application
Biography:
Ganesh R Bhand is a Senior Research Fellow (UGC-BSR) in the Department of Physics of Savitribai Phule Pune University, Pune (India). He is pursuing his PhD under the supervision of Dr. N B Chaure, Department of Physics, Savitribai Phule Pune University. He has completed his MPhil from the same university. His field of research is “Metal and semiconductor nanostructure for hybrid organic – inorganic solar cell”. Presently, he is working on the synthesis and characterization of Au, Ag, CdSe, and CdTe nanostructures through wet chemical and solvothermal routes for solar cell applications.
Abstract:
Cadmium selenide (CdSe) quantum dots (QDs) were prepared by solvothermal route. Subsequently an inorganic QDs-organic semiconductor (copper phthalocyanine) nanocomposite (i.e CuPc:CdSe nanocomposites) were produced by different concentrations of QDs varied in CuPc. The nanocomposite thin films have been prepared by means of spin coating technique. The optical, structural and morphological properties of nanocomposite films have been investigated. The transmission electron microscopy (TEM) confirmed the formation of QDs having average size of ~ 4 nm. The X-ray diffraction pattern exhibits cubic crystal structure of CdSe with reflection to (111), (220) and (311) at 25.4áµ’, 42.2áµ’ and 49.6áµ’ respectively. The additional peak observed at lower angle at 6.9áµ’ in nanocomposite thin films are associated to CuPc. The field emission scanning electron microscopy (FESEM) observed that surface morphology varied with increasing concentration of CdSe QDs. The obtained nanocomposite show significant improvement in the thermal stability as compared to the pure CuPc indicated by thermo-gravimetric analysis (TGA) in thermograph. The effect in the Raman spectra of composite samples gives a confirm evidence of homogenous dispersion of CdSe in the CuPc matrix and their strong interaction between them to promote charge transfer property. The success of reaction between composite was confirmed by Fourier transform infrared spectroscopy (FTIR). The photo physical properties were studied using UV - visible spectroscopy. The enhancement of the optical absorption in visible region for nanocomposite layer was observed with increasing the concentration of CdSe in CuPc. This composite may obtain the maximized interface between QDs and polymer for efficient charge separation and enhance the charge transport. Such nanocomposite films for potential application in fabrication of hybrid solar cell with improved power conversion efficiency.
Mpho P Ngoepe
Rhodes University, South Africa
Title: Control of Mesoporous Silica Nanoparticles physicochemical properties through control of synthetic parameter using Box-Behnken design
Biography:
Mpho Phehello Ngoepe has experience in pharmaceutical formulation and design for drug delivery system. Obtained an MSc(Med) in Pharmaceutics at the University of the Witwatersrand (South Africa). Currently doing a PhD in Chemistry at Rhodes University (South Africa), to better understand and gain experience in nanomaterial chemistry. Using experimental design, various synthetic parameters can be used to improve the performance of currently utilized drug delivery carriers. The understanding of material chemistry and physics can aid in improving drug delivery systems.
Abstract:
Statement of the Problem: Mesoporous silica nanoparticles (MSN) have been utilized in drug delivery due to their controllable release kinetics. The control of the physicochemical properties of nanoparticles for applications is stated to be complex despite the use of computational model. The pH, molar ratio of silica source and water and calcination temperature impact in drug delivery have not been studied before. Understanding of these critical synthetic parameters can aid in controlling the particle size, pore structure and size, surface chemistry and drug loading capacity. Methodology & Theoretical Orientation: Box-Behnken design was utilized for evaluation of these parameters. Whereby, post-grafting of amine, surface chemistry post calcination, drug loading particle size and pore structure were studied. For application in drug delivery, rifampicin was loaded into the particles followed by capping with pH responsive chitosan. Findings: Based on the surface response plot from the experimental design, the size of the particle indicates to be dependent on the amount of water available for hydrolysis and dissolution to occur at a near neutral pH. The highest size obtained was 609±44.44 (n=3), whereby pH 8 and molar ratio of 126 was used. The smallest size was observed was observed at pH 12. The calcination temperature played a role in condensation of the free silanols which lead to changes in the grafting potential of the silica surface to (3-Aminopropyl) triethoxysilane. The amount of drug entrapped indicates can be improve though increase in particle size and increase in the porous particle structure. Conclusion & Significance: This works adds to previous work that indicate that TEOS: water ratio plays a role in particle size, pH plays a role in the control of the network structure, whilst calcination temperature affects the degree of post synthesis silanol condensation.