A5062669671- Graphene research and applications
- Molecular Junctions and Nanostructures
- Force Microscopy Techniques and Applications
- 2D Materials and Applications
- Nanowire Synthesis and Applications
- Advanced Sensor and Energy Harvesting Materials
- Bone Tissue Engineering Materials
- Advanced Materials and Mechanics
- Chemical Synthesis and Characterization
- Polymer Surface Interaction Studies
- Origins and Evolution of Life
- Thermal and Kinetic Analysis
- Porphyrin and Phthalocyanine Chemistry
- MXene and MAX Phase Materials
- Dental materials and restorations
- Analytical Chemistry and Sensors
- Surface and Thin Film Phenomena
- Photonic Crystals and Applications
- Electrospun Nanofibers in Biomedical Applications
- Nanopore and Nanochannel Transport Studies
- Electronic and Structural Properties of Oxides
- Calcium Carbonate Crystallization and Inhibition
- Collagen: Extraction and Characterization
- Semiconductor materials and devices
- Graphene and Nanomaterials Applications
Universidade Federal de Ouro Preto
2021-2024
Universidade Federal de Minas Gerais
2009-2015
Phyllosilicate minerals are an emerging class of naturally occurring layered insulators with large bandgap energy that have gained attention from the scientific community. This lamellar materials has been recently explored at ultrathin two-dimensional level due to their specific mechanical, electrical, magnetic, and optoelectronic properties, which crucial for engineering novel devices (including heterostructures). Due these phyllosilicates can be considered promising low-cost nanomaterials...
The synthesis and characterization of two-dimensional (2D) molecular crystals composed long linear phosphonic acids atop graphene is reported. Using scanning probe microscopy in combination with first-principles calculations, we show that these true 2D are oriented along the armchair direction only, thereby enabling an easy determination flake orientation. We have also compared doping level flakes via Raman spectroscopy. presence crystal induces a well-defined shift Fermi level,...
Single-layer graphene structures and devices are commonly defined using reactive ion etching plasma with O2 or Ar as the gaseous etchants. Although optical microscopy Raman spectroscopy widely used to determine appropriate duration of dry etching, additional characterization atomic force (AFM) reveals that residual and/or byproducts persist beyond point where aforementioned methods suggest complete etching. Recognizing incomplete may have deleterious effects on downstream processing, AFM is...
Studies concerning the impact of nanomaterials, especially fullerene (C(60) ), in fresh water environments and their effects on physiology aquatic organisms are still scarce conflicting. We aimed to assess vitro brain gill homogenates carp Cyprinus carpio, evaluating redox parameters. A suspension was prepared by continued stirring under fluorescent light during two months. The concentration measured total carbon content ultraviolet-visible spectroscopy nephelometry. Characterization C(60)...
Long-range order evolution of self-assembled phosphonic acid multilayers as a function temperature is studied here for two molecules with different alkyl chain length. By using synchrotron conventional diffraction, distinct configurations are retrieved on and their thermodynamic behavior monitored by energy-dispersive diffraction. This later technique allows us to observe the system near order-disorder temperatures, well determine most stable in range from room up 120 °C. Planar also...
Self-assembled monolayers, bilayers, and other structures of mixed phosphonic acids were investigated using atomic force microscopy. Octadecylphosphonic acid (OPA, 18 carbon atoms in the alkyl chain) was solution, with different ratios, octylphosphonic (OcPA, 8 deposited onto mica substrates. monolayers formed, no evidence phase separation, from pure OPA up to 5:10 OPA/OcPA ratio (despite large chain length difference). It found that water plays a crucial role morphology self-assembled their...
In this paper, we address the challenge of identifying grain boundaries on molybdenum disulphide (MoS2) surface at nanometre scale using a simple self-assembled monolayer (SAM) decoration method. Combined with atomic force microscopy, octadecylphosphonic acid monolayers readily reveal in MoS2 ambient conditions, without need resolution measurements under vacuum. Additional ab initio calculations allow us to obtain preferred orientation SAM structure relative beneath, and therefore, together...
Industrial applications of nanomaterials require large-scale production methods, such as liquid phase exfoliation (LPE). Regarding this, it is imperative to characterize the obtained materials tailor parameters medium, duration, and mechanical energy source desired applications. This work presents results statistical analyses talc flakes by LPE in four different media. Talc a phyllosilicate that can be exfoliated into nanoflakes with great properties. Sodium cholate at two concentrations...
Abstract The production of 2D material flakes in large quantities is a rapidly evolving field and cornerstone for their industrial applicability. Although flake has advanced fast pace, its statistical characterization somewhat slower, with few examples the literature which may lack either modelling uniformity and/or physical equivalence to actual dimensions. present work brings methodology threefold target: (i) propose set morphological shape parameters that correctly map relevant...
In this work, we make use of an atomic layer deposition (ALD) surface reaction based on trimethyl-aluminum (TMA) and water to modify O-H terminated self-assembled layers octadecylphosphonic acid (OPA). The structural modifications were investigated by X-ray reflectivity, diffraction, force microscopy. We observed a significant improvement in the thermal stability ALD-modified molecules, with existence supramolecular packing structure up 500 °C. Following experimental observations, density...
Combined microscopy techniques are used to establish the usability of phosphonic acid layers as promoters hydroxyapatite (HAp) growth. Using spread coating, octadecylphosphonic (OPA) self-assembled bilayers delivered thin natural oxide layer a titanium film surface with no prior treatment. These aggregate two major advantages moieties surfaces: nucleation crystals from ionic solution and affinity for both HAp crystals. The functionalized substrates bare (control) samples immersed in an...