scholarly journals Polystyrene/calcium phosphate nanocomposites: Contact angle studies based on water and methylene iodide

2008 ◽  
Vol 2 (7) ◽  
pp. 528-538 ◽  
Author(s):  
S. P. Thomas ◽  
S. Thomas ◽  
R. Abraham ◽  
S. Bandyopadhyay
Keyword(s):  
Contact Angle ◽  
Calcium Phosphate ◽  
Methylene Iodide

The influence of proteins on calcium phosphate deposition over titanium implants studied by dynamic contact angle analysis and XPS

1997 ◽  
Vol 10 (2) ◽  
pp. 95-104 ◽  
Author(s):  
Ana Paula Valagão Amadeu do Serro ◽  
Anabela Catarino Fernandes ◽  
Benilde de Jesus ◽  
Vieira Saramago
Keyword(s):  
Contact Angle ◽  
Calcium Phosphate ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Titanium Implants ◽  
Contact Angle Analysis

Effect of Calcium Titanate and/or Titanium-Phosphides in the Properties of Titanium Composites for Implant Materials

2014 ◽  
Vol 906 ◽  
pp. 226-231
Author(s):  
Enori Gemelli ◽  
Patrícia Borges da Silva Maia ◽  
Fabio Nery ◽  
Nelson Heriberto Almeida Camargo ◽  
Vinícius André Rodrigues Henriques ◽  
...  
Keyword(s):  
Contact Angle ◽  
Compressive Strength ◽  
Calcium Phosphate ◽  
Phosphoric Acid ◽  
Conventional Method ◽  
Pure Titanium ◽  
Calcium Titanate ◽  
Molar Concentration ◽  
Implant Materials ◽  
Lower Contact

Titanium-based composites containing TixPy phase (s) or CaTiO3 and TixPy phase (s) were produced by a non conventional method using suitable mixtures of TiH2 powder and phosphoric acid (TiH2/P), or TiH2 and 10 vol.% of calcium phosphate (TiH2/CP), respectively. The composites were produced with the same phosphor molar concentration. The mixtures were prepared by ultrasound in water, dried in a rotary evaporator, pressed at 600 MPa and vacuum-sintered at 1200 °C for 2 hours. The mixtures were well dispersed by ultrasound and agglomerate-free. The analyses show that titanium particles were coated with TixPy phase (s) for the TiH2/P composite or with an intermediary layer of TixPy phase (s) and an external deposit of calcium titanate for the TiH2/CP composite. The TiH2/P composite presented higher compressive strength and about the same contact angle compared to the TiH2/CP composite. However, both materials displayed lower contact angle than that of pure titanium.

scholarly journals Bioactive Cellulose Nanocrystal-Poly(ε-Caprolactone) Nanocomposites for Bone Tissue Engineering Applications

2021 ◽  
Vol 9 ◽  
Author(s):  
Jung Ki Hong ◽  
Shelley L. Cooke ◽  
Abby R. Whittington ◽  
Maren Roman
Keyword(s):  
Contact Angle ◽  
Tensile Strength ◽  
Calcium Phosphate ◽  
Ultimate Tensile Strength ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Mineral Formation ◽  
Water Contact ◽  
Bone Scaffolds ◽  
The Matrix

3D-printed bone scaffolds hold great promise for the individualized treatment of critical-size bone defects. Among the resorbable polymers available for use as 3D-printable scaffold materials, poly(ε-caprolactone) (PCL) has many benefits. However, its relatively low stiffness and lack of bioactivity limit its use in load-bearing bone scaffolds. This study tests the hypothesis that surface-oxidized cellulose nanocrystals (SO-CNCs), decorated with carboxyl groups, can act as multi-functional scaffold additives that (1) improve the mechanical properties of PCL and (2) induce biomineral formation upon PCL resorption. To this end, an in vitro biomineralization study was performed to assess the ability of SO-CNCs to induce the formation of calcium phosphate minerals. In addition, PCL nanocomposites containing different amounts of SO-CNCs (1, 2, 3, 5, and 10 wt%) were prepared using melt compounding extrusion and characterized in terms of Young's modulus, ultimate tensile strength, crystallinity, thermal transitions, and water contact angle. Neither sulfuric acid-hydrolyzed CNCs (SH-CNCs) nor SO-CNCs were toxic to MC3T3 preosteoblasts during a 24 h exposure at concentrations ranging from 0.25 to 3.0 mg/mL. SO-CNCs were more effective at inducing mineral formation than SH-CNCs in simulated body fluid (1x). An SO-CNC content of 10 wt% in the PCL matrix caused a more than 2-fold increase in Young's modulus (stiffness) and a more than 60% increase in ultimate tensile strength. The matrix glass transition and melting temperatures were not affected by the SO-CNCs but the crystallization temperature increased by about 5.5°C upon addition of 10 wt% SO-CNCs, the matrix crystallinity decreased from about 43 to about 40%, and the water contact angle decreased from 87 to 82.6°. The abilities of SO-CNCs to induce calcium phosphate mineral formation and increase the Young's modulus of PCL render them attractive for applications as multi-functional nanoscale additives in PCL-based bone scaffolds.

Poly(ethylene-co-vinyl acetate)/calcium phosphate nanocomposites: contact angle, diffusion and gas permeability studies

2010 ◽  
Vol 18 (6) ◽  
pp. 1277-1285 ◽  
Author(s):  
Selvin Thomas Palakattukunnel ◽  
Sabu Thomas ◽  
P. A. Sreekumar ◽  
Sri Bandyopadhyay
Keyword(s):  
Contact Angle ◽  
Calcium Phosphate ◽  
Vinyl Acetate ◽  
Gas Permeability ◽  
Poly Ethylene ◽  
Permeability Studies

Investigation of behavior of the dynamic contact angle in a problem of convective flows

2017 ◽  
Vol 5 (4) ◽  
pp. 27-42
Author(s):  
O.N Goncharova ◽  
◽  
I.V. Marchuk ◽  
A.V. Zakurdaeva ◽  
◽  
...  
Keyword(s):  
Contact Angle ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Convective Flows

Controlling porosity and density of nanocellulose aerogels for superhydrophobic light materials

TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 145-153 ◽  
Author(s):  
Chengua Yu ◽  
Feng Wang ◽  
Shiyu Fu ◽  
Lucian Lucia
Keyword(s):  
Contact Angle ◽  
Freeze Drying ◽  
Engine Oil ◽  
High Porosity ◽  
Water Mixture ◽  
Waste Engine Oil ◽  
Hydrophobically Modified ◽  
Static Contact ◽  
Oil Water ◽  
Hydrophobic Material

A very low-density oil-absorbing hydrophobic material was fabricated from cellulose nanofiber aerogels–coated silane substances. Nanocellulose aerogels (NCA) superabsorbents were prepared by freeze drying cellulose nanofibril dispersions at 0.2%, 0.5%, 0.8%, 1.0%, and 1.5% w/w. The NCA were hydrophobically modified with methyltrimethoxysilane. The surface morphology and wettability were characterized by scanning electron microscopy and static contact angle. The aerogels displayed an ultralow density (2.0–16.7 mg·cm-3), high porosity (99.9%–98.9%), and superhydrophobicity as evidenced by the contact angle of ~150° that enabled the aerogels to effectively absorb oil from an oil/water mixture. The absorption capacities of hydrophobic nanocellulose aerogels for waste engine oil and olive oil could be up to 140 g·g-1 and 179.1 g·g-1, respectively.

High Resolution Displacement of Functional Groups onto Fluorocarbon Resin Surface by Using ArF Excimer Laser

1996 ◽  
Vol 451 ◽  
Author(s):  
T. Shimizu ◽  
M. Murahara
Keyword(s):  
Contact Angle ◽  
High Resolution ◽  
Laser Beam ◽  
Thin Layer ◽  
Functional Groups ◽  
Excimer Laser ◽  
Laser Fluence ◽  
Large Area ◽  
Three Solutions ◽  
Arf Excimer Laser

ABSTRACTA Fluorocarbon resin surface was selectively modified by irradiation with a ArF laser beam through a thin layer of NaAlO2, B(OH)3, or H2O solution to give a hydrophilic property. As a result, with low fluence, the surface was most effectively modified with the NaAlO2 solution among the three solutions. However, the contact angle in this case changed by 10 degrees as the fluence changed only 1mJ/cm2. When modifying a large area of the surface, high resolution displacement could not be achieved because the laser beam was not uniform in displacing functional groups. Thus, the laser fluence was successfully made uniform by homogenizing the laser beam; the functional groups were replaced on the fluorocarbon resin surface with high resolution, which was successfully modified to be hydrophilic by distributing the laser fluence uniformly.

Electron Holographic Nano-Characterization of Gold Catalyst at Interface

2002 ◽  
Vol 727 ◽  
Author(s):  
S. Ichikawa ◽  
T. Akita ◽  
M. Okumura ◽  
M. Haruta ◽  
K. Tanaka
Keyword(s):  
Contact Angle ◽  
Titanium Oxide ◽  
Gold Catalyst ◽  
Three Dimensional ◽  
High Resolution Electron Microscopy ◽  
Electron Holography ◽  
Gold Particles ◽  
Oxide Support ◽  
The Mean ◽  
A Charge

AbstractThe catalytic properties of nanostructured gold catalyst are known to depend on the size of the gold particles and to be activated when the size decreases to a few nanometers. We investigated the size dependence of the three-dimensional nanostructure on the mean inner potential of gold catalysts supported on titanium oxide using electron holography and high-resolution electron microscopy (HREM). The contact angle of the gold particles on the titanium oxide tended to be over 90° for gold particles with a size of over 5 nm, and below 90° for a size of below 2 nm. This decreasing change in the contact angle (morphology) acts to increase the perimeter and hence the area of the interface between the gold and titanium oxide support, which is considered to be an active site for CO oxidation. The mean inner potential of the gold particles also changed as their size decreased. The value of the inner potential of gold, which is approximately 25 V in bulk state, rose to over 40 V when the size of the gold particles was less than 2 nm. This phenomenon indicates the existence of a charge transfer at the interface between gold and titanium oxide. The 3-D structure change and the inner potential change should be attributed to the specific electronic structure at the interface, owing to both the “nano size effect” and the “hetero-interface effect.”

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