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Study of synthesis parameters on the physical properties and morphology of smart PNIPAAm hydrogels Cover

Study of synthesis parameters on the physical properties and morphology of smart PNIPAAm hydrogels

Open Access
|Sep 2022

Figures & Tables

Fig. 1

Sample H1.0 after gelation
Sample H1.0 after gelation

Fig. 2

Swelling ratios of the hydrogels at room temperature and 37°C in (a) stirred samples and (b) unstirred samples
Swelling ratios of the hydrogels at room temperature and 37°C in (a) stirred samples and (b) unstirred samples

Fig. 3

1H NMR spectra of Nipam, H1.0, H2.0, H3.0, and H4.0 (500 MHz, D2O).
1H NMR spectra of Nipam, H1.0, H2.0, H3.0, and H4.0 (500 MHz, D2O).

Fig. 4

FTIR-ATR spectra of all hydrogel samples
FTIR-ATR spectra of all hydrogel samples

Fig. 5

(a) EDS spectrum of hydrogel H1.A and (b) image of the region analyzed by EDS
(a) EDS spectrum of hydrogel H1.A and (b) image of the region analyzed by EDS

Fig. 6

XRD patterns of the hydrogels.
XRD patterns of the hydrogels.

Fig. 7

SEM morphologies of the samples of H2.0, H3.0, and H4.0. Magnification of the sample of H2.0: (a) 600 ×; (b) 2,500 ×; (c) 8,000 ×. Magnification of the sample of H3.0: (d) 600 ×; (e) 2,500 ×; (f) 5,000 ×. Magnification of the sample of H4.0: (g) 600 ×; (h) 2,400 ×; (i) 10,000 ×
SEM morphologies of the samples of H2.0, H3.0, and H4.0. Magnification of the sample of H2.0: (a) 600 ×; (b) 2,500 ×; (c) 8,000 ×. Magnification of the sample of H3.0: (d) 600 ×; (e) 2,500 ×; (f) 5,000 ×. Magnification of the sample of H4.0: (g) 600 ×; (h) 2,400 ×; (i) 10,000 ×

Fig. 8

Morphologies of the sample of H1.0. Magnifications: (a) 600 ×; (b) 2,500 ×; (c) 10,000 ×.
Morphologies of the sample of H1.0. Magnifications: (a) 600 ×; (b) 2,500 ×; (c) 10,000 ×.

Fig. 9

Morphologies of the samples of H1.A, H2.A, and H3.A. Magnification of the sample of H1.A: (a) 600 ×; (b) 2,500 ×; (c) 5,000 ×. Magnification of the sample of H2.A: (d) 600 ×; (e) 2,500 ×; (f) 10,000 ×. Magnification of the sample of H3.A: (g) 600 ×; (h) 2,500 ×; (i) 8,000 ×
Morphologies of the samples of H1.A, H2.A, and H3.A. Magnification of the sample of H1.A: (a) 600 ×; (b) 2,500 ×; (c) 5,000 ×. Magnification of the sample of H2.A: (d) 600 ×; (e) 2,500 ×; (f) 10,000 ×. Magnification of the sample of H3.A: (g) 600 ×; (h) 2,500 ×; (i) 8,000 ×

Fig. 10

PNIPAAm hydrogels’ thermogravimetric analysis (TGA)
PNIPAAm hydrogels’ thermogravimetric analysis (TGA)

NMR 1H Spectra results

GroupsChemical dislocation (ppm)Integration ratio/number of hydrogens involved
H1.01.226.04 / 6
1.661.89 / 2
2.091.17 / 1
3.981.00 / 1
H2.01.086.00 / 6
1.642.19 / 2
1.961.17 / 1
3.831.16 / 1
H3.01.225.93 / 6
1.781.98 / 2
2.101.33 / 1
3.971.00 / 1
H4.01.216.00 / 6
1.682.32 / 2
2.111.12 / 1
3.980.85 / 1

Semiquantitative chemical composition (wt%) of the samples using EDS analysis

GroupsCarbonOxygenNitrogenPlatinum
H1.A77.708.0912.241.97
H1.072.514.863.9318.70
H2.A74.764.000.0521.20
H2.080.1910.905.423.48
H3.A75.766.02018.21
H3.073.657.03019.32
H4.065.417.81026.78

Hydrogel groups, reagents concentration, and synthesis process

GroupsNIPAM (mmol)MBA (mmol)APS (mmol)NMB (mmol)Mol %Magnetic stirring
H1.A*2.210.1350.0780.09787.7×5.4×3.1×3.8Yes
H2.A*2.260.2390.0740.10184.5×8.9×2.8×3.8Yes
H3.A*2.220.4460.0590.07679.3×15.9×2.1×2.7Yes
H1.02.210.1320.0760.09787.8×5.2×3.2×3.8No
H2.02.220.2350.0750.10284.4×8.9×2.8×3.9No
H3.02.230.4430.0570.07479.5×15.8×2.3×2.6No
H4.02.220.4430.0760.07578.9×15.7×2.8×2.6No

Thermogravimetric data of the hydrogels

Sample1st event2nd event3rd event
Tpeak (°C)ResidueTmax (°C)Tpeak (°C)ResidueTmax (°C)Tpeak (°C)Residue
H1.A744%26529120%34938161%
H1.0545%26228618%36039771%
H2.A1047%34238967%---
H2.0566%27130720%37841269%
H3.A1116%34638162%---
H3.0614%25927921%35038366%
H4.0654%26028123%35137665%
DOI: https://doi.org/10.2478/msp-2022-0020 | Journal eISSN: 2083-134X | Journal ISSN: 2083-1331
Language: English
Page range: 196 - 205
Submitted on: Mar 14, 2022
Accepted on: May 31, 2022
Published on: Sep 13, 2022
Published by: Wroclaw University of Science and Technology
In partnership with: Paradigm Publishing Services
Publication frequency: 4 issues per year

© 2022 Luíza Braga Ferreira dos Santos, Francielly Moura de Souza Soares, Emília Santos Monteiro, Maria Elisa Rodrigues Coimbra, Carlos Nelson Elias, published by Wroclaw University of Science and Technology
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.