The Effect Of Polymer Membrane On The Engineering And Science Disciplines

Diffusion occurs as passive transport in cells through a selectively permeable membrane. In this experiment, the membrane that was used was dialysis tubing. The questions this experiment modeled were, which solutions would diffuse and what molecules were small enough to diffuse through the selected membranes. When the experiment concluded, the data supported which solutions diffused and at what rate they diffused. It is discussed that the permeability of a solute across a membrane is affected differently from method to method. Each process has comparable variables that will affect the rate or ability to diffuse, but some require more work, energy, or other substances needed to allow diffusion to occur.

The objective of this experiment was to test the effect of a specialized type of diffusion called osmosis, “which involves in selective transport of water molecules across a selectively permeable membrane” (Lab Manual 2nd edition). It was hypothesized that osmosis will occur when there is an uneven distribution of solute in a solvent. The more abundant the solute is in solvent, the higher the rate of osmosis through the diffusion gradient forming a hypertonic or hypotonic solution. Solvent with equal or no solute forms an isotonic solution. Throughout this lab, data was collected and compiled to analyze these effects across selectively permeable membranes. The results indicated that the water molecules indeed move from

I obtained the results from the experiment supported my predictions because as the the concentration Na+ Cl- was increased from 5 mM to 10 mM (by adding more Na+ Cl-), the osmotic pressure also increased. However, after the membrane was changed to 50 MWCO, the Na+ Cl- molecules could diffuse easily through the membrane and did not caused an increase in osmotic pressure.

The purpose of these experiments is to examine the driving force behind the movement of substances across a selective or semiperpeable plasma membrane. Experiment simulations examine substances that move passively through a semipermeable membrane, and those that require active transport. Those that move passively through the membrane will do so in these simulations by facilitated diffusion and filtration. The plasma membrane’s structure is composed in such a way that it can discriminate as to which substances can pass into the cell. This enables nutrients to enter the cell, while keeping unwanted substances out. Active

The dialysis membrane’s permeability was tested with four substances. Starch, sulfate ion, chloride ion, and albumin are all substances of different sizes. Albumin is a protein that is fairly large so it cannot diffuse through a semi-permeable membrane. Ions such as the sulfate and chloride ion are small enough that they can go through the microscopic pores of the dialysis tubing.

In this experiment, we will investigate the effect of solute concentration on osmosis. A semi‐permeable membrane (dialysis tubing) and sucrose will create an osmotic environment similar to that of a cell. Using different concentrations of sucrose (which is unable to cross the membrane) will allow us to examine the net movement of water across the membrane.

The objective of this experiment is to develop an understanding of the molecular basis of diffusion and osmosis and its physiological importance. Students will analyze how solute size and concentration affect diffusion across semi-permeable membranes and how these processes affect water potential. Students will also calculate water potential of plant cells.

In order to assimilate diffusion through a permeable membrane potassium permanganate and methylene blue were used in experiment. The objective was to compare the rates at which the liquid compound of different molecular weight diffused through agar. This was achieved by obtaining agar in a petri dish with two wells to hold the liquid compounds. The rate was measured by time and diameter distance diffused. This process was observed for 60 minutes at 15 minute intervals.

In which two of the dialysis bag contain tap water. The three other Bags were 20% sucrose 40% sucrose and 60% sucrose. To perform this lab we prepare each of 5 bags with their designated sucrose solution. In this experiment the dialysis tubing acted as selectively permeable membrane. The dialysis bag allows the passage of water molecule only because the sucrose molecule are too large to pass through the membranes. After filling those bags ,we then placed the bags into five separate beakers. Four of this beakers contained only tap waters, and the fifth beakers contains solution of 60% sucrose. We filled the first dialysis bag with 10 ml of tap water, next we filled the second bag with 10ml of 20% sucrose, the third bag was filled with 10 ml of 40% sucrose solution while the fourth bag was filled with 10ml of Tap water (H2O). We made sure that when filling this bags that we removed as much air as possible before clamping of the end of each bag. We also made sure that all of the bags rest soft and floppy instead of firm to ensure that experiment will work properly. Next we placed dialysis bag ,one through four in their own separate beakers which was filled with tap water (H2O), and our fifth bag was full of tap water was placed in beaker filled with just enough of the 60% sucrose solution to cover the bag. All of these bags remained in their designated solutions for 45 minutes. However, all of this bags were quickly removed every

*Purpose-How does the molarity of the solution affect the diffusion and osmosis across a semi-permeable membrane?

Performing this experiment provides evidence and example of how various stresses effect this membrane and to what extent will they remain intact.

Initially known amount of zeolite was uniformly dispersed in N-Methyl-2-pyrrolidone (NMP) using ultrasonication for 2 h at 30°C. 3 g of PVC polymer was then added to the solution with stirring at ambient temperature for 1-2 hours and left undisturbed for few hours to result bubble free homogenous polymer solution. This solution was further cast on a glass plate and kept in oven maintained at60°C for 48h to produce dense membrane. This method of producing dense membrane is termed as “solution casting and solvent evaporative

The diffusion lab required the class to explore the concept of diffusion, using dialysis tubing as a model of a selectively permeable membrane. We were able to observe the random kinetic energy of glucose, IKI, and water molecules through the dialysis tubing as the molecules moved themselves between the solutions in the beaker and the dialysis bag. After 30 minutes, the solution in the beaker tested positive for the presence of glucose, proving that the glucose molecules had diffused from the bag to the beaker. The IKI solution must have also diffused across the membrane because although initially only the solution in the beaker contained IKI, the solution within the dialysis bag turned purple-black by the end of 30 minutes, indicating that

Gel-Filtration Chromatography is a commonly used method used in order purify a protein from a mixture, by means of separations. Different biomolecules differ in size, or their molecular weight. In the gel matrix inside the chromatography column, there are gel beads which are porous to allow certain sized molecules to enter. The molecules that are able to enter the pores of the gel, are held in stationary phase and will elute from the column later on, these are usually smaller, to medium sized molecules. Larger molecules that are not able to fit in the pores will elute out of the column first, they are involved in mobile phase where they just go straight through the column without interacting with the gel beads. Smaller molecules will have a higher elution volume, while the larger molecules will have a lower elution volume. The volume to elute the protein is inversely proportional to the molecules size.

The PDMS, PTMSP, zeolite and composite membranes have been reported to have separation factors of 4.4–10.8, 9–26, 7–59, 12–106, respectively. However, in some cases, the separation factor gets way higher than expected, such as a separation factor of 218 during the separation of ethanol (98.2% permeate) over water-ethanol solution (20% by weight ethanol), using a silicate zeolite membrane (Nomura et al., 2002). In general, separation factors are ranked in the following order: PDMS < PTMSP < composite membranes < zeolite