Interpretation of lanthanide oxide and hydroxide solubilities based on their bulk and surface properties

The physicochemical properties of an enhanced adsorbent material generated by clays and fungal biomass can be modified systematically. We used spectroscopic techniques to investigate the interaction mechanisms between biomass and clay and how surface properties change with synthesis temperature and clay amounts. Biomass-clay complexes were synthesized and either shock-frozen and freeze-dried or dried at 60 °C in the oven. Surface and bulk properties were analyzed by scanning electron microscopy, attenuated total reflectance-Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and by wettability and surface charge measurements. Interactions of specific biomass-related molecules with clay and changes in physicochemical properties were observed. Higher amounts of clay caused a decrease in particle aggregation while the biomass arranged more evenly. XPS proved interactions due to exchange reactions between Na from the clay and biomass external organic compounds. FTIR, wettability, surface charge, and XPS indicated a less ordered arrangement of the biomass on the clay when drying was performed at 60 °C. The properties of these types of materials define their potential use in future applications. These results indicate the possibility of the selective creation of bioclays: more hydrophobic, with a higher content of organic matter or more specific functional groups on the surface.

Bulk, surface and blood-contacting properties of polyether polyurethanes modified with polydimetnylsiloxane macroglycols

Event Abstract Back to Event Biomedical coatings prepared by magnetron sputtering Sandra Rodil1, Phaedra Silva-Bermudez2, Argelia Almaguer-Flores3 and Rene Olivares-Navarrete4 1 Universidad Nacional Autónoma de México, Instituto de Investigaciones en Materiales, Mexico 2 Instituto Nacional de Rehabilitación, Terapia Celular y Medicina Regenerativa, Mexico 3 Universidad Nacional Autónoma de México, Facultad de Odontología, Mexico 4 Virginia Commonwealth University, 2Department of Biomedical Engineering, United States Introduction: Nowadays, it is generally accepted that surfaces are critically important to determine the degree of tissue interaction between an implanted device and the host. Thus, much more importance has been given to study and modify the biomaterial surfaces to improve biocompatibility, cell adhesion, proliferation and differentiation. During the last years the research has evolved from the improvement of bulk properties and design of the implants to the development of a variety of bio-functional surface modifications, such as surface topography at both micro and nanoscale, adhesion of growth factors or coating deposition. The use of coatings allows the synthesis of hybrid materials, in which surface and bulk properties are de-coupled, so different functionalities (biocompatibility, antibacterial, etc...) could be obtained using the same substrate material. Materials: Metal oxide coatings (TiOx, ZrOx, TaOx and NbOx). Methods: The deposition of the coatings was done by reactive magnetron sputtering on stainless steel or titanium substrates. The coatings structure, composition and surface properties were measured. Electrochemical characterization using different electrolytes that simulate the biological fluids were used to evaluate the corrosion resistance provided by the coatings and the effect of the electrolyte composition on the response. The biological-surface interactions were also evaluated by studying protein-surface (adsorption), bacteria-surface (adhesion and biofilm formation) and cell-surface (adhesion, proliferation and differentiation) interactions. Discussion: The paper will presented a summary of the biological response from the four oxide coatings and the correlation between such response and the surface properties, including the effect of crystallinity or nanoroughness. One important factor to analyze is the fact that by using sputtered deposited coatings, it is possible to evaluate separately the effect of the surface chemical composition and the roughness, not so easily achieved when bulk materials are used. Conclusions: The in vitro results obtained from the different oxide coatings suggested that by using deposition methods, it is possible to create biomedical coatings that mimic the cellular response of the Ti-optimized metallic implants, with the advantage that such coatings could be deposited on hard-polymers or ceramics. UNAM PAPIIT Keywords: corrosion, Surface modification, surface property, Cell response Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: Poster Topic: Composites: polymeric, ceramic and metallic Citation: Rodil S, Silva-Bermudez P, Almaguer-Flores A and Olivares-Navarrete R (2016). Biomedical coatings prepared by magnetron sputtering. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.01672 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Sandra Rodil Phaedra Silva-Bermudez Argelia Almaguer-Flores Rene Olivares-Navarrete Google Sandra Rodil Phaedra Silva-Bermudez Argelia Almaguer-Flores Rene Olivares-Navarrete Google Scholar Sandra Rodil Phaedra Silva-Bermudez Argelia Almaguer-Flores Rene Olivares-Navarrete PubMed Sandra Rodil Phaedra Silva-Bermudez Argelia Almaguer-Flores Rene Olivares-Navarrete Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Many industrial processes involve the modification of surfaces. The semiconductor and microelectronics industries are extremely reliant upon surface processing [1], but other applications include solar cells, MEMS and microfluidics, thermal barrier coatings, and fuel cells. Optical measurements are commonly used to indirectly quantify the surface and bulk properties of materials. Unlike direct imaging methods, in which the local surface topography is visualized, indirect methods provide information on surface and bulk properties which are averaged over the entire area being sampled. Typically, a beam of light is directed at the surface to be measured, and the light interacts with the surface to produce the reflected or diffracted light that is then measured by a photodetector. One advantage of indirect measurement techniques is that they are non-invasive, and therefore can be used in extreme or harsh processing environments such as vacuum chambers and reaction vessels by passing the light through windows. These in situ optical sensors have been used for process control of film thickness and chemical composition. However, many more microscopic and nanoscale surface properties can be measured and potentially controlled using optical sensors. The barriers include the difficulty of modeling the optical response, the difficulty of inverting these relationships to robustly infer surface properties, and the practicality of including windows on the chamber to enable optical access. However, to create precise nanostructures in a high-throughput manufacturing setting, real-time measurement and control will be required, and optical sensors are expected to play a significant role.

Surface tension method is a simple and popular method to study the surface as well as bulk properties of nonionic surfactants, including Brij‐35, which is a poly‐oxyethylated surfactant. In this study, the surface tension of the solutions of Brij‐35 in the presence of sodium nitrate and sodium sulfate in binary mixed media of alcohol–water was measured precisely. The alcohols used in this study were methanol, ethanol, and propan‐1‐ol. The surface properties such as surface excess concentration ( Γ max ) and minimum surface area ( A min ), bulk properties such as critical micelle concentration (CMC) and packing parameter (P), and thermodynamic properties and of micellization of the surfactant were determined using the surface tension data. The presence of inorganic salts is found to decrease the CMC of Brij‐35 in water–alcohol‐mixed media, whereas the presence of short‐chain alcohols separately increases the CMC values of Brij‐35. The alkyl part of the short‐chain alcohol also plays a significant role in the micellization of Brij‐35. The results were explained on the basis of molecular and ionic interactions, including ion–ion, ion–solvent, hydrophobic, and hydrophilic, among the various species in the system.

Properties of extruded poly(tetramethylene oxide) Polyurethane block copolymers for blood-contacting applications

The evolution of shape in finite nuclei shows tremendous changes in nuclear structure properties within the nuclear Segre chart. The neutron-rich nuclei around mass $A\sim100$ are important due to the changing behavior of nuclear shapes across isotopic chains. We have investigated the ground state bulk properties of nuclei for N(Z)=38, 40 and 42 isotonic(isotopic) series within the covariant density functional theory using the DD-ME2 (finite range) and DD-PC1 (zero range) interactions. A search for the shell closure at and around N(Z)$\sim40$ has been done in the chosen isotopic and isotonic series. The impact of shape evolution or deformation on nuclear charge radii and the surface properties has been analyzed in the mass region of about $70\sim100 $. The surface properties such as the symmetry energy, neutron pressure, and symmetry energy curvature have been studied using the coherent density fluctuation model. The study gives the correlation of symmetry energy and its coefficients with the nuclear quadrupole deformation. On ignoring the effects of shape evolution, a good correlation of the surface properties can be obtained with the neutron skin-thickness of nuclei. N(Z)=40 is found to behave as a magic number in the Z(N) = 40 and 42 series, and N(Z) = 38 as a deformed magic in Z(N) = 38 series only. In addition, a deformed magic behavior is obtained at N = 58 across all the isotopic series corresponding to both DD-ME2 and DD-PC1 interactions. While the magicity of N = 70 is suggested by DD-ME2 interaction. The symmetry energy of nuclei is changed by an amount of 1-2 MeV on varying the quadrupole deformation.

The bulk and surface properties of liquid crystals are very important for the performance of liquid crystal displays and devices. The bulk properties of thermotropic liquid crystals depend strongly on the molecular structure and on the molecular interactions. The liquid crystal surface properties, which is of vital importance for the alignment of the liquid crystals and thus for the appearance and operation of these devices, depends, in addition, on the solid surface-liquid crystal interactions. Both liquid crystal physical properties can effectively be controlled by external factors that result in changes of the molecular structure and, hence, of the molecular properties. Here, we report on the reversible changes of bulk and surface liquid crystal properties caused by the photoisomerisation process that takes place in the organic photochromic materials. The photocontrol of these physical properties could be utilized in liquid crystal devices such as all-optical switches, light modulators and optical memories.

Characterization of surface and bulk properties of α-Tocopherol blended and γ irradiated UHMWPE sandwich nanocomposites

Self-assembling and foaming properties of nonionic, cardanol-based surfactants in aqueous solutions

An interatomic potential for simulation of defects and phase change of zirconium

Atmospheric plasma treatment is an effective and economical surface treatment technique. The main advantage of this technique is that the bulk properties of the material remain unchanged while the surface properties and biocompatibility are enhanced. Polymers are used in many biomedical applications; such as implants, because of their variable bulk properties. On the other hand, their surface properties are inadequate which demands certain surface treatments including atmospheric pressure plasma treatment. In biomedical applications, surface treatment is important to promote good cell adhesion, proliferation, and growth. This article aim is to give an overview of different atmospheric pressure plasma treatments of polymer surface, and their influence on cell-material interaction with different cell lines.

ABSTRACTTwo series of polyester and polyether waterborne polyurethanes (WPUs) modified with poly[(3,3,3‐trifluoropropyl)methylsiloxane] (PTFPMS) were synthesized by prepolymerization method and the effect of PTFPMS on surface and bulk properties were investigated by a variety of experimental methods. FTIR and DSC results showed that the polyester WPU has better compatibility between soft segments and hard segments than polyether WPU in bulk and the degree of phase separation increased in polyester WPU but decreased in polyether WPU with increasing PTFPMS. ARXPS analysis revealed the migration of PTFPMS to WPU surface and the migration ability of Si element was better than F element. AFM images demonstrated that the surface of WPU films became rougher as PTFPMS content increased. The enrichment of PTFPMS with low surface energy and roughened surface imparted good hydrophobicity and oleophobicity to WPU films and polyether WPU has better surface properties compared with polyester WPU. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46473.

Soft magnetoactive elastomers (MAEs) are smart materials that respond to external magnetic fields by dynamically altering their mechanical properties. They are composed of magnetically responsive microparticles embedded within a soft polymer matrix, exhibiting an effective shear modulus of up to 100 kPa. In recent decades, MAEs' bulk properties have been successfully exploited for applications such as dynamic vibration damping, vibration sensing, and actuation in soft robotics. Recent research has shifted to their surface properties, revealing promising results on tunable surface features such as roughness, adhesion, and wetting. Even the transport of small solid and fluid objects was demonstrated. The associated surface effects can be significantly enhanced through the precise engineering of surface topography. In this article, an efficient laser micromachining technique, with a resolution of 15 µm, is presented, which enables rapid prototyping of MAE surfaces. It allows the creation of various complex shapes and offers functionality beyond the one achievable with traditional molding techniques. Additionally, the approach is versatile and can be applied to any polymer that sufficiently absorbs the laser light. As an example, a lamellar surface micro-pattern fabrication process and its characterization by optical and scanning electron microscopies are shown. Its response to a magnetic field is demonstrated. The technique provides a flexible and fast solution for optimizing polymer surface design across a wide range of applications.

Is work function a surface or a bulk property?