Isoelectric Point Determination of Functionalized CVD Coatings

Graduate Student Mentor: Ramya Kumar Undergraduate Student: Aymen Maktari

• Chemical Vapor Deposition polymerization (CVD)

• Objective

• Streaming Potential

• Results

• Conclusion and Future Work

Overview

Figure 1Image adopted from Bally and Lahann Laboratory (2013)

CVD

• Surface charge influences protein adsorption and the degree of adsorption

• Apply Streaming Potential to determine the isoelectric point of selected polymers

Figure 2Functional groups examined circled in red (Gleason, 2015)

Objective

Streaming Potential

0 2 4 6 8 1 0 1 2 1 4

-4

-2

0

2

4

6

8

1 0

1 2

pH

Mv

Figure 4Image adopted from Barz, D., Garg, A., & Saini, R (2014)

Figure 3 Image adopted from Anton Paar (2012)

Figure 5

Results: Aminomethyl and Amine

Polymer Coating IEPPPX-Aminomethyl (Thick) (Yellow) 4.285PPX-Aminomethyl (Thin) (Blue) 4.7PPX-Amine (Dark Green) 3.7

2.5 3 3.5 4 4.5 5 5.5 6 6.5

-80

-60

-40

-20

0

20

40

60

80

100

pH

MV

Results: Aldehydes Polymer Coating IEP

PPX-Aldehyde (Vacuum) (Red) 3.82

PPX-Aldehyde (Non-Vacuum) (Grey) 3.629

2.5 3 3.5 4 4.5 5 5.5 6 6.5

-100

-80

-60

-40

-20

0

20

40

60

80

pH

Mv

Results: Alcohol and Aminomehtyl

Polymer Coating IEPPPX-Alcohol (Green) 3.80PPX-Aminomethyl (Thick) (Yellow) 4.285

PPX-Aminomethyl (Thin) (Blue) 4.7

2.5 3 3.5 4 4.5 5 5.5 6 6.5

-80

-60

-40

-20

0

20

40

60

80

100

pH

Mv

Results: Halogens

Polymer Coating IEP

PPX-Trifluoride (Purple) 3.78

PPX-Dichloro (Brown) 3.42

2.5 3 3.5 4 4.5 5 5.5 6

-80

-60

-40

-20

0

20

40

60

pH

Mv

Conclusion and Future Work

• The PPX backbone is highly electronegative and thus when compared to the functional groups exerts a proportionally greater impact on the charge• Future Work: Compare PPX to functionalized pyridinophane (or other

mono/di-substituted rings)