Search results for "SURFACE MODIFICATION"
showing 10 items of 417 documents
Design of siliceous lignins – Novel organic/inorganic hybrid sorbent materials
2009
Novel nanoporous lignin(lignocellulose)/SiO2 hybrid materials were designed using the sol–gel process. X-ray photoelectronic spectroscopy, Fourier transform infrared spectroscopy and 29Si and 13C nuclear magnetic resonance spectroscopy were applied to characterize the hybrids’ surface and bulk structure. Nitrogen and water vapor sorption were used for assessment of porous structure parameters and hydrophobization of matrices, respectively. The efficiency of the hybrid materials obtained was proved by adsorption tests with potential inorganic (Cu2+) and organic (2,4-dichlorophenoxyacetic acid) pollutants.
Reversible guest-induced gate-opening with multiplex spin crossover responses in two-dimensional Hofmann clathrates.
2021
Spin crossover (SCO) compounds are very attractive types of switchable materials due to their potential applications in memory devices, actuators or chemical sensors. Rational chemical tailoring of these switchable compounds is key for achieving new functionalities in synergy with the spin state change. However, the lack of precise structural information required to understand the chemical principles that control the SCO response with external stimuli may eventually hinder further development of spin switching-based applications. In this work, the functionalization with an amine group in the two-dimensional (2D) SCO compound {Fe(5-NH2Pym)2[MII(CN)4]} (1M, 5-NH2Pym = 5-aminopyrimidine, MII =…
Influence of alkylphosphonic acid grafting on the electronic and magnetic properties of La2/3Sr1/3MnO3 surfaces
2015
Self-assembled monolayers (SAMs) are highly promising materials for molecular engineering of electronic and spintronics devices thanks to their surface functionalization properties. In this direction, alkylphosphonic acids have been used to functionalize the most common ferromagnetic electrode in organic spintronics: La2/3Sr1/3MnO3 (LSMO). However, a study on the influence of SAMs grafting on LSMO electronic and magnetic properties is still missing. In this letter, we probe the influence of alkylphosphonic acids-based SAMs on the electronic and magnetic properties of the LSMO surface using different spectroscopies. We observe by X-ray photoemission and X-ray absorption that the grafting of …
How Electrical Heterogeneity Parameters of Ion-Exchange Membrane Surface Affect the Mass Transfer and Water Splitting Rate in Electrodialysis
2020
Electrodialysis (ED) has been demonstrated as an effective membrane method for desalination, concentration, and separation. Electroconvection (EC) is a phenomenon which can essentially increase the mass transfer rate and reduce the undesirable water splitting effect. Efforts by a number of researchers are ongoing to create conditions for developing EC, in particular, through the formation of electrical heterogeneity on the membrane surface. We attempt, for the first time, to optimize the parameters of surface electrical heterogeneity for ion-exchange membranes used in a laboratory ED cell. Thirteen different patterns on the surface of two Neosepta anion-exchange membranes, AMX and AMX-Sb, w…
The role of angiogenesis in implant dentistry part I: Review of titanium alloys, surface characteristics and treatments
2015
Background: Angiogenesis plays an important role in osseointegration process by contributing to inflammatory and regenerative phases of surrounding alveolar bone. The present review evaluated the effect of titanium alloys and their surface characteristics including: surface topography (macro, micro, and nano), surface wettability/ energy, surface hydrophilicity or hydrophobicity, surface charge, and surface treatments of dental implants on angiogenesis events, which occur during osseointegration period. Material and Methods: An electronic search was performed in PubMed, MEDLINE, and EMBASE databases via OVID using the keywords mentioned in the PubMed and MeSH headings regarding the role of …
Toxicity of gold-nanoparticles: Synergistic effects of shape and surface functionalization on micromotility of epithelial cells
2010
Nanoparticle exposure is monitored by a combination of two label-free and non-invasive biosensor devices which detect cellular shape and viscoelasticity (quartz crystal microbalance), cell motility and the dynamics of epithelial cell-cell contacts (electric cell-substrate impedance sensing). With these tools we have studied the impact of nanoparticle shape on cellular physiology. Gold (Au) nanoparticles coated with CTAB were synthesized and studied in two distinct shapes: Spheres with a diameter of (43 ± 4) nm and rods with a size of (38 ± 7) nm × (17 ± 3) nm. Dose-response experiments were accompanied by conventional cytotoxicity tests as well as fluorescence and dark-field microscopy to v…
Surface functionalization of metal-organic frameworks for improved moisture resistance
2018
Metal-organic frameworks (MOFs) are a class of porous inorganic materials with promising properties in gas storage and separation, catalysis and sensing. However, the main issue limiting their applicability is their poor stability in humid conditions. The common methods to overcome this problem involve the formation of strong metal-linker bonds by using highly charged metals, which is limited to a number of structures, the introduction of alkylic groups to the framework by post-synthetic modification (PSM) or chemical vapour deposition (CVD) to enhance overall hydrophobicity of the framework. These last two usually provoke a drastic reduction of the porosity of the material. These strategie…
Biomaterial Surface Hydrophobicity-Mediated Serum Protein Adsorption and Immune Responses.
2019
The nature of the protein corona forming on biomaterial surfaces can affect the performance of implanted devices. This study investigated the role of surface chemistry and wettability on human serum-derived protein corona formation on biomaterial surfaces and the subsequent effects on the cellular innate immune response. Plasma polymerization, a substrate-independent technique, was employed to create nanothin coatings with four specific chemical functionalities and a spectrum of surface charges and wettability. The amount and type of protein adsorbed was strongly influenced by surface chemistry and wettability but did not show any dependence on surface charge. An enhanced adsorption of the …
Shifting the Photoresponse of ZnO Nanowires into the Visible Spectral Range by Surface Functionalization with Tailor-Made Carbon Nanodots
2018
We report on the surface functionalization of ZnO nanowires (NWs) with specifically synthesized carbon nanodots (C-dots, CDs) that allows us to shift the photoresponse of the NWs far into the visib...
XPS and SIMS study of aluminium native oxide modifications induced by Q-switched Nd:YAG laser treatment
2006
Publié suite au congrès ECASIA: 11th European Conference on Applications of Surface and Interface Analysis, 25-30 September 2005, Vienna, Austria; International audience; During laser cleaning of aluminium in ambient atmosphere, modifications of the metal surface can be induced by transient thermal effects. This work aims to characterize the modification of the aluminium oxide layer on pure aluminium for a wide range of power per area using a Q-switched Nd :YAG (1064 nm) laser with two pulse durations, 10 and 180 ns. Experiments were carried out with single laser shots in ambient air at fluences (e.g. energy per area) below the ablation regime. For 10-ns pulses with fluences between 0.7 and…