Glow discharge oxygen plasma surface modification of electrospun polylactic acid-cellulose acetate composite fiber
Joanna Abigael Dasecoa,b*, Juvy J. Monserateb.c, Gerardo V. Ilaganc, Henry J. Ramosa a Plasma Physics Laboratory, National Institute of Physics, University of the Philippines, Diliman Quezon City 1101, Philippines b Materials Science and Engineering Program, University of the Philippines, Diliman Quezon City 1101, Philippines c Physical, Inorganic and Materials Science Laboratory, Central Luzon State University, Science City of Munoz, Nueva Ecija, Philippines
Corresponding author: jdaseco@nip.upd.edu.ph
Abstract. Oxygen plasma treatment of electrospun fibers mats was conducted using a low pressure DC parallel plate plasma device
…show more content…
It can be fabricated as films, fibers, and other packaging material.
However, some disadvantages of polylactic acid are its inherent hydrophobic nature which makes it difficult for adhesion and its weak thermal properties compared to synthetic polymers [1-3]. The hydrophobic nature of polylactic acid also can elicit inflammatory response in the tissue when used as scaffolds for tissue engineering [3].
Hence, there is still a need to modify the properties of polylactic acid fibers. One type of modification technique is matrix polymer modification wherein the PLA fibers are mechanically or chemically reinforce. Natural fibers have been widely used as reinforcements for biodegradable polymer fibers and are called natural fiber composites. Cellulosic fibers from plants such as jute, coconut coir, hemp, flax have been utilized as reinforcements
…show more content…
The droplet was photographed using a Dino-Lite Pro digital microscope and water contact angle was measured using DinoCapture 2.0 Three Points Arc function. Contact angle of the untreated and plasma treated samples were obtained as an average of ten drops.
2.3.2 Vertical Wicking Test
Vertical wicking test was conducted to determine the wicking rate of untreated and plasma treated samples. A strip of the fiber mats with dimensions 25 mm x 10 mm was attached to a ruler and its bottom end is brought into contact with deionized water contained in a small petri dish. A digital camera was used to record the whole process of the wicking test through video. Still snapshots were extracted from the video for every second of the process and the height of the liquid front was subsequently recorded. The wicking kinetics was then described using the modified Washburn equation discussed by Chatterjee [9]:
h^2= W_c t where: W_c=(R_e γ
The reaction was repeated 3 times and average rate noted. From these rates a graph was plotted which describes the relationship of the pressure produced and number of drops added. The reaction rates were measured by Kpa/min and were written to 4 figures for precise results. Time was measured by stop watch. Table 4 shows a summary of all the groups which participated in the lab session.
Genetic engineering is changing the DNA code to express different traits. A plasmid is a circular piece of DNA that contains important genetic information. Recombinant DNA is the product after inserting your desired genes. The genes we hoped to insert in the pGLO lab were the GFP gene and the ampicillin resistance gene. GFP was needed so that we would tell if the ampicillin resistance gene had been properly placed when the bacteria glowed under a UV light.
The purpose of this lab is to observe the reaction between hydrochloric acid and magnesium metal. When the substances are reacted over water, the products produced are a salt in aqueous solution and a gas. While the salt remains in the water as part of a solution, the gas produced will float to the top. Though water vapor pressure will affect the pressure of the gas in the eudiometer, it is possible to apply Dalton’s law of partial pursues to find the dry pressure of the gas. When the dry pressure is determined, the volume of the gas at STP can then be determined and what the experimental volume of one mole of the gas would be at STP.
In this lab, the water molecules stick strongly together and
Identification of Unknown Solutions and Ammonium Salts preAice Chemistry Lab Report Descriptions of unknown solutions: Unknown Descriptions A Clear, colorless, odorless liquid. B Clear, colorless, odorless liquid. C Clear, red-brown, odorless liquid D Clear, yellow-orange, odorless liquid.
Lab Report 5: Acetylsalicylic Acid (Aspirin) Synthesis Name: Divya Mehta Student #: 139006548 Date Conducted: November 19th 2014 Date Submitted: November 26th 2014 Partner’s Name: Kirsten Matthews Lab Section: Wednesday 2:30 L9 IAs Name: Brittany Doerr Procedure: For the procedure, see lab manual (CH110 Lab Manual, Fall 2014) pages 96-98. Wilfrid Laurier University Chemistry Department. Fall 2014. Acetylsalicylic Acid (Aspirin) Synthesis.
In the second lab “Water down a String”, when I had first attempted to pour the water down the string, which was dry, it had failed and did not form into beads at first. After I had dampened it, and did a second trial, the water formed into beads and rolled easily down the string and into the second beaker. This again goes back to water’s high surface tension,
Modeling of Contact Angle for a Liquid in Contact with a Rough Surface When a solid is in contact with liquid, the molecular attraction will reduce the energy of the system below that for the two separated surfaces. This is expressed by the Dupré equation Figure-1 2.1 Wenzel Model: The Wenzel model (Robert N. Wenzel 1936) describes the homogeneous wetting regime, as seen in Figure 2, and is defined by the following equation for the contact angle on a rough surface. where is the apparent contact angle which corresponds to the stable equilibrium state (i.e. minimum free energy state for the system). The roughness ratio, r, is a measure of how surface roughness affects a homogeneous surface.
Soap disrupts the hydrogen bonds in water, which are the building blocks that keep water molecules together, so when soap severs those bonds, soap causes the water to overflow and the surface tension breaks. By adding more soapy water to the penny, the soapy water’s surface tension will break faster than the tap water. The average number of drops with tap water was higher than the number of drops with soapy water, once again proving my hypothesis right. The highest number of drops I counted with the soapy water was much less than my lowest number of drops with tap water. The highest number of drops I recorded for tap water was more than double the lowest number of soapy water drops.
The results of the phenol-sulfuric acid analysis conducted in this experiment suggest that the data acquired was relatively precise but inaccurate with respect to the given carbohydrate concentrations of the soda and Gatorade samples. Using a standard curve generated from a glucose solution with a known concentration, the carbohydrate concentration of the samples was determined (in terms of glucose) and a low coefficient of variation was calculated. However, a high percent relative error was apparent in the analysis of both samples. This may have been due to the fact that the analysis was conducted assuming glucose was the carbohydrate of interest, while, in fact, a significant portion of the monosaccharides would have existed as fructose (a
Properties of Substances Express Lab 1)The purpose of this lab was to compare the physical properties of different types of solids and how the properties of solids are determined by their intermolecular forces and their intramolecular bonds. Then we were to classify each type of solid as either ionic, metallic, non-polar molecular, polar molecular, or network. Paraffin wax classified as a non-polar molecular, Silicon dioxide was classifies as a network, Sodium chloride was classified as ionic, Sucrose was classified as polar molecular and Tin was classified as metallic. (2)The intermolecular forces that are present in Paraffin wax are dispersion forces, because it is non-polar and carries a negative charge. Followed by Sucrose that has
Acids are proton donors in chemical reactions which increase the number of hydrogen ions in a solution while bases are proton acceptors in reactions which reduce the number of hydrogen ions in a solution. Therefore, an acidic solution has more hydrogen ions than a basic solution; and basic solution has more hydroxide ions than an acidic solution. Acid substances taste sour. They have a pH lower than 7 and turns blue litmus paper into red. Meanwhile, bases are slippery and taste bitter.
Introduction The goal of the experiment is to examine how the rate of reaction between Hydrochloric acid and Sodium thiosulphate is affected by altering the concentrations. The concentration of Sodium thiosulfate will be altered by adding deionised water and decreasing the amount of Sodium thiosulphate. Once the Sodium thiosulphate has been tested several times. The effect of concentration on the rate of reaction can be examined in this experiment.
Abstract The unknown concentration of benzoic acid used when titrated with standardized 0.1031M NaOH and the solubility was calculated at two different temperatures (20◦C and 30◦C). With the aid of the Van’t Hoff equation, the enthalpy of solution of benzoic acid at those temperatures was determined as 10.82 KJ. This compares well with the value of 10.27KJ found in the literature.
Fix or replace damaged tissue; biology has always been the main concern for scientists. Today, the most important instrument for tissue engineering scientists to produce replacement tissues and implants to repair or replace damaged tissue. Tissue engineering is generating a new field of study in which the principles of engineering and biology to correct the damaged tissue, uses and can renewal, operation and maintenance of tissue healing. In order to use an ideal scaffold Tissue engineering should have features such as non-toxic Cell and tissue properties to be fit.