Marine antifouling efficacy of amphiphilic poly(coacrylate) grafted PDMSe: effect of graft molecular weight Cary A. Kuliasha a , John A. Finlay b , Sofia C. Franco b , Anthony S. Clare b , Shane J. Stafslien c , and Anthony B. Brennan a a Department of Materials Science and Engineering, University of Florida, Gainesville, FL, USA; b School of Marine Science and Technology, Newcastle University, Newcastle upon Tyne, UK; c Office of Research and Creative Activity, North Dakota State University, Fargo, ND, USA Supplemental Information Bulk Copolymer Characterization GPC analysis was performed on bulk copolymer samples collected from grafting solutions and purified via dialysis. The M w of the bulk copolymer was used to estimate the graft molecular weight as a function of changing the concentration of the chain transfer agent, TGA (Figure S1). These results indicate that the TGA mediated chain growth polymerization could produce a wide range of M w ’s; however, the precise control of M w was lacking as indicated by high deviations in M w obtained batch-batch. Better M w control is possible utilizing living polymerization 1
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Amazon S3€¦ · Web viewPCAgPDMS coatings adsorbed water due to the hydrophilic nature of the surface grafts in a fashion not seen for PDMSe coatings, and this swelling resulted
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Marine antifouling efficacy of amphiphilic poly(coacrylate) grafted PDMSe: effect of graft
molecular weight
Cary A. Kuliashaa, John A. Finlayb, Sofia C. Francob, Anthony S. Clareb, Shane J. Stafslienc, and
Anthony B. Brennana
aDepartment of Materials Science and Engineering, University of Florida, Gainesville, FL, USA;
bSchool of Marine Science and Technology, Newcastle University, Newcastle upon Tyne, UK;
cOffice of Research and Creative Activity, North Dakota State University, Fargo, ND, USA
Supplemental Information
Bulk Copolymer Characterization
GPC analysis was performed on bulk copolymer samples collected from grafting
solutions and purified via dialysis. The Mw of the bulk copolymer was used to estimate the graft
molecular weight as a function of changing the concentration of the chain transfer agent, TGA
(Figure S1). These results indicate that the TGA mediated chain growth polymerization could
produce a wide range of Mw’s; however, the precise control of Mw was lacking as indicated by
high deviations in Mw obtained batch-batch. Better Mw control is possible utilizing living
polymerization techniques; however, it is unlikely that the large range of overall Mw’s produced
utilizing TGA would be possible with living techniques.
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Figure S1. (a) Effect of increasing [TGA] on the MW of bulk copolymer purified from solution
and (b) representative GPC chromatograms of copolymers with different MW values produced by
varying [TGA]. Data points represent the arithmetic mean with error bars representing one
standard deviation, n=4
ATR-FTIR analysis of homopolymers was performed to identify distinguishable peaks
that could be used for copolymer analysis (Figure S2). Copolymer composition was estimated by
performing peak fitting analysis of the carbonyl region (Figure S3) and fitting the respective
heights of each of the three carbonyls normalized by the -CH2 bend to a Beer’s law type relation.
This relation was derived by performing IR analysis of blends of PAA conjugated with Na+
(neutral dialyzed) and PAAm at different ratios (Figure S4). Blends were made by solvating the
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homopolymers in water (pH=7.5), allowing them to mix thoroughly, and drying them to a
homogenous film. The Beer’s law relationships for AA and AAm content show good linear
relationships (Figure S5). PMA was not incorporated into these blends due to its insolubility in
water, and PMA composition was estimated by subtracting the calculated composition of AA
and AAm from 100%. These relationships were validated by performing the same peak fitting
procedure on poly(AA Na+-c-AAm-c-MA) blended with varying concentrations of either PAA or
PAAm.
Figure S2. ATR-FTIR spectra of poly(acrylate) homopolymers. All polymers were synthesized
in lab, purified by dialysis, and dried by rotary evaporation. The 1452 cm-1 peak is the -CH2 bend
attributed to the polymer backbone. Carbonyl designations are as follows: 1732 cm-1 PMA, 1704
cm-1 PAA, 1664 cm-1 PAAm, and 1556 cm-1 PAA Na+.
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Figure S3. ATR-FTIR spectra of a ternary poly(co-acrylate) bulk sample showing the fitted
peaks utilized for copolymer composition analysis.
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Figure S4. ATR-FTIR spectra of a homopolymers, homopolymer blends, and ternary copolymer
utilized to calculate the Beer-Lambert law relationship.
Figure S5. Beer’s law type of relation used for copolymer compositional analysis. The carbonyl
peak height (either 1556 cm-1 for PAA or 1664 cm-1 for PAAm) was normalized with the -CH2
bend at 1452 cm-1.
PCAgPDMS Characterization
The Owens-Wendt method was used to calculate the surface free energy (SFE), γS
(mN/m), of test surfaces using W-MI and MI-GL probe liquid pairs. Equation S1 was used to
calculate the surface’s polar and dispersive (γSp and γS
d) components using the measured contact
angle (θ) of each liquid and polar/dispersive values found in Table S1. The overall SFE, γS, was
determined by averaging the values of the probe liquid pairs obtained using Equation S2.
γ L (1+cos (θ ) )2
=√γ Sd γ L
d+√γ Sp γ L
p (S1)
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γ=γ p+γ d (S2)
Table S1. SFE values for probe liquids used for SFE calculations of PDMSe surfaces.
IS 1100SR 53.0 ± 4.6 88.3 ± 1.2 IS 1100SR 26.3 ± 9.9 77.2 ± 3.0*Percentage removal is reported by comparing each count of diatom biomass remaining post-removal to the mean
diatom initial biomass pre-removal per coating type. Arithmetic average ± 95% confidence interval, n=4. IS 700 was
excluded from bioassay 6 due to issues with coating adherence to well plates.
Table S3. Percentage removal values of N. incerta diatoms performed on coated glass slides for