Title

Nano-imaging For Dialysis Membrane Surface Characterization Using (AFM)

1.Proposal Summary

2.Introduction

3.Research Problem (300 words)

4.Objectives (50 words)

:::have it already just to help you :::

1. Image the surface topography of membrane surfaces to calculate surface roughness and nanomechanical properties before and after use in dialysis process.
2. Image the surface topography of re-usable dialysis membrane to find if blood particles including proteins are adsorbed on the surfaces giving rise to increased surface roughness.

Image the surface topography of dialysis hollow-fibers for mapping surface electrostatic potential and how it is affected with multiuse.

5.Importance of research (175 words)

6.Literature Review (500 words)

7.Research Project Design & Methodology (250 words)

::: have it already just to help you :::

Characterization Methods:

1. Physical:

• AFM

Nanomechanical Property Determination:

Young’s Modulus Determination Using Atomic Force Microscopy (AFM): Topography and force spectroscopy images of the samples prepared from specific aim, will be obtained in constant-force mode using an AFM (Dimension ICON, Bruker (available in the department)) and Silicon AFM probe (Tap300, resonant frequency 300 kHz and spring constant 40 N/m). The scan size will be 5 μm at various locations over a larger area of the nanocomposite/ nanofibers.  The Young’s Modulus for each site will be measured using the Hertz model. A dissection of sample Force curve is shown in figure.

The deflection of the cantilever through approach and retract cycle is used to create a force-distance plot. At point (1) in the plot, the probe and substrate are far apart and no interaction occurs. As the probe and substrate are brought closer together, a force arises between the two inducing a deflection of the cantilever, which can be measured. At point (2) an attractive force is shown driving the probe and substrate together. At point (3) the probe and substrate have come into contact. Point (4) illustrates the probe and the surface moving together while in contact, with the slope of this line being a measure of the compliance of the substrate. The direction of the z ramp is reversed and the probe and substrate are slowly separated, shown at point (5). The additional force that is seen is due to adhesive contact. At some point, shown here as point (6), the force induced by deformation of the cantilever is sufficient to overcome the adhesive force and the probe and the substrate come out of contact. For a biological system, this is the ligand-receptor interaction force.

The water contactangle will be measured using Attension Optical Tensiometer Theta 200 (Biolin Scientific, Stockholm, Sweden) following a standardized protocol in the biomaterials and tissue engineering laboratory,

1. Statistics

All quantification values including Young’s Modulus, water contact angle will be presented as mean ± standard deviation (SD). After the assessment of significant differences by one-way analysis of variance (ANOVA), differences among groups will be established with t-test analysis by a two population comparison. P-values <0.05 will be considered statistically significant.

These references have to be in the proposal, also you have full permission to add what you need

8.References

[1][2][3][4][5]

[1]         K. Yamamoto et al., “Membrane potential and charge density of hollow-fiber dialysis membranes,” J. Memb. Sci., vol. 355, no. 1–2, pp. 182–185, 2010.

[2]         K. Yamazaki, M. Matsuda, K. Yamamoto, T. Yakushiji, and K. Sakai, “Internal and surface structure characterization of cellulose triacetate hollow-fiber dialysis membranes,” J. Memb. Sci., vol. 368, no. 1–2, pp. 34–40, 2011.

[3]         M. Hayama, F. Kohori, and K. Sakai, “AFM observation of small surface pores of hollow-fiber dialysis membrane using highly sharpened probe,” vol. 197, pp. 243–249, 2002.

[4]         M. Holzweber et al., “Surface characterization of dialyzer polymer membranes by imaging ToF-SIMS and quantitative XPS line scans Surface characterization of dialyzer polymer membranes by imaging ToF-SIMS and quantitative XPS line scans,” vol. 019011, no. 2015, 2016.

[5]         J. Barzin, C. Feng, K. C. Khulbe, T. Matsuura, S. S. Madaeni, and H. Mirzadeh, “Characterization of polyethersulfone hemodialysis membrane by ultrafiltration and atomic force microscopy,” vol. 237, pp. 77–85, 2004.