Contact angle Research Papers - Academia.edu (original) (raw)

Fabrication of microfluidic systems capable of extracting and isolating nucleic acids from biological samples and preparing them for downstream applications within the same device is of interest as on-chip sample preparation reduces the... more

Fabrication of microfluidic systems capable of extracting and isolating nucleic acids from biological samples and preparing them for downstream applications within the same device is of interest as on-chip sample preparation reduces the time and effort expended on multi-step benchtop procedures. A microfluidic chip capable of cell lysis, nucleic acid extraction and immobilization has been developed in our laboratory. This report focuses on substrate development and chip integration of the nucleic acid immobilization platform. The immobilization region was initially developed using poly-adenylated mRNA released from normal human lymphoblastoid cells. After immobilization, the mRNA remains functional for amplification by the reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR (qPCR) gene expression analyses. Detailed surface functionalization, chemical modification, and covalent oligonucleotide immobilization methods are described. Vapor and liquid ...

This work explores the methodology for micron-scale water droplet contact angle derivation for the warty surface of octocoral sclerites. The calcite-made sclerites of the Red Sea octocoral Dendronephthya hemprichi have been chosen as a... more

This work explores the methodology for micron-scale water droplet contact angle derivation for the warty surface of octocoral sclerites. The calcite-made sclerites of the Red Sea octocoral Dendronephthya hemprichi have been chosen as a model for this study. Water droplet condensation on the sclerites has been in-situ investigated using Quanta 200 FEG (field emission gun) ESEM (environmental scanning electron microscope) under wet environmental conditions. Two different analysis methods of droplet top and side views have been applied to determine the contact angle based on the secondary electron images. The ESEM image analysis for the sclerites indicates that their surface is hydrophilic. The microscopic contact angle is measured to be 45.3 ± 6.3. The macroscopic contact angle has been calculated by using the Wenzel model for the surface texturing of the sclerites.

This study focuses on the surface modification of the commercial aromatic polyamide (PA) thin-film composite (TFC) reverse osmosis (RO) membranes with thermo-responsive copolymers poly(N-isopropylacrylamide-co-acrylamide) (P(NIPAM-co-Am))... more

This study focuses on the surface modification of the commercial aromatic polyamide (PA) thin-film composite (TFC) reverse osmosis (RO) membranes with thermo-responsive copolymers poly(N-isopropylacrylamide-co-acrylamide) (P(NIPAM-co-Am)) for improved membrane properties. Firstly, thermo-responsive copolymers P(NIPAM-co-Am) with certain lower critical solution temperature (LCST) were synthesized by free radical copolymerization in aqueous solution. The resultant copolymers were then used to modify the commercial TFC

Polymer fiber can be formed by pulling a thread of polymeric liquid if the fiber solidifies before it breaks up by capillary thinning. Fiber diameter is well correlated with a processing parameter that is a simple function of viscosity,... more

Polymer fiber can be formed by pulling a thread of polymeric liquid if the fiber solidifies before it breaks up by capillary thinning. Fiber diameter is well correlated with a processing parameter that is a simple function of viscosity, surface tension and evaporation rate. The ...

Inkjet printing is the emerging technology for the deposition of a variety of particles. The reliable printing of nano-silver inks shows the possibilities of digital fabrication of microelectronic circuits and raises the question for... more

Inkjet printing is the emerging technology for the deposition of a variety of particles. The reliable printing of nano-silver inks shows the possibilities of digital fabrication of microelectronic circuits and raises the question for further use with other particles. To compete with common thick-film screen printing as a production method it is consequential and necessary to investigate the inkjet printing of all passive electronic thick-film components. Inductors are frequently required in electronic circuits, yet they represent a main challenge for thick-film printing. With the development of new materials, which are suitable for low-temperature cofired ceramic processes, the integration of passive components promises new applications. In a first step, different ferrite particle compositions are dispersed to stabilized inks that can be used with a commercial inkjet print head. The stability of the ink is fundamental for reliable drop formation. In addition, the viscosity must fit ...

This work presents a study of superficial properties of polyacrylonitrile (PAN) films obtained by extrusion process. This innovative material was submitted to microwave plasma treatment generated at low pressure. The contact angle was... more

This work presents a study of superficial properties of polyacrylonitrile (PAN) films obtained by extrusion process. This innovative material was submitted to microwave plasma treatment generated at low pressure. The contact angle was measured with and without treatment in nitrogen and argon plasma, by the pendant drop technique. The work of adhesion was calculated by the Young–Dupré equation. The surface

This paper reports on the wettability and aging behaviors of the silicon wafers that had been cleaned using a piranha (3:1 mixture of sulfuric acid (H 2 SO 4 , 96%) and hydrogen peroxide (H 2 O 2 , 30%), 120 1C), SC1 (1:1:5 mixture of NH... more

This paper reports on the wettability and aging behaviors of the silicon wafers that had been cleaned using a piranha (3:1 mixture of sulfuric acid (H 2 SO 4 , 96%) and hydrogen peroxide (H 2 O 2 , 30%), 120 1C), SC1 (1:1:5 mixture of NH 4 OH, H 2 O 2 and H 2 O, at 80 1C) or HF solution (6 parts of 40% NH 4 F and 1 part of 49% HF, at room temperature) solution, and treated with gaseous plasma. The silicon wafers cleaned using the piranha or SC1 solution were hydrophilic, and the water contact angles on the surfaces would increase along with aging time, until they reached the saturated points of around 701. The contact angle increase rate of these wafers in a vacuum was much faster than that in the open air, because of loss of water, which was physically adsorbed on the wafer surfaces. The silicon wafers cleaned with the HF solution were hydrophobic. Their contact angle decreased in the atmosphere, while it increased in the vacuum up to 951. Gold thin films deposited on the hydrophilic wafers were smoother than that deposited on the hydrophobic wafers, because the numerous oxygen groups formed on the hydrophilic surfaces would react with gold adatoms in the sputtering process to form a continuous thin film at the nucleation stage. The argon, nitrogen, oxygen gas plasma treatments could change the silicon wafer surfaces from hydrophobic to hydrophilic by creating a thin (around 2.5 nm) silicon dioxide film, which could be utilized to improve the roughness and adhesion of the gold thin film.

Siloxane–polyurethane paints were formulated and characterized for coating properties and performance as fouling-release (FR) marine coatings. Paints were formulated at 20 and 30 pigment volume concentrations with titanium dioxide, and... more

Siloxane–polyurethane paints were formulated and characterized for coating properties and performance as fouling-release (FR) marine coatings. Paints were formulated at 20 and 30 pigment volume concentrations with titanium dioxide, and aminopropyl-terminated poly(dimethylsiloxane) (APT-PDMS) loadings were varied from 0 to 30% based on binder mass. The coatings were characterized for water contact angle, surface energy (SE), gloss, and pseudobarnacle (PB) adhesion. The assessment of the FR performance compared with polyurethane (PU) and silicone standards through the use of laboratory biological assays was also performed. Biofilm retention and adhesion were conducted with the marine bacterium Cellulophaga lytica, and the microalgae diatom Navicula incerta. Live adult barnacle reattachment using Amphibalanus amphitrite was also performed. The pigmented coatings were found to have properties and FR performance similar to those prepared without pigment. However, a higher loading of PDMS was required, in some cases, to obtain the same properties as coatings prepared without pigment. These coatings rely on a self-stratification mechanism to bring the PDMS to the coating surface. The slight reduction in water contact angle (WCA) and increase in pseudobarnacle release force with pigmentation suggests that pigmentation slowed or interfered with the self-stratification mechanism. However, increasing the PDMS loading is an apparent method for overcoming this issue, allowing for coatings having similar properties as those of clear coatings and FR performance similar to those of silicone standard coatings.