Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Apr 28;14(9):1810.
doi: 10.3390/polym14091810.

Toward a Better Understanding of the Gelation Mechanism of Methylcellulose via Systematic DSC Studies

Affiliations

Toward a Better Understanding of the Gelation Mechanism of Methylcellulose via Systematic DSC Studies

Beata Niemczyk-Soczynska et al. Polymers (Basel). .

Abstract

A methylcellulose (MC) is one of the materials representatives performing unique thermal-responsive properties. While reaching a critical temperature upon heating MC undergoes a physical sol-gel transition and consequently becomes a gel. The MC has been studied for many years and researchers agree that the MC gelation is related to the lower critical solution temperature (LCST). Nevertheless, a precise description of the MC gelation mechanism remains under discussion. In this study, we explained the MC gelation mechanism through examination of a wide range of MC concentrations via differential scanning calorimetry (DSC). The results evidenced that MC gelation is a multistep thermoreversible process, manifested by three and two endotherms depending on MC concentration. The occurrence of the three endotherms for low MC concentrations during heating has not been reported in the literature before. We justify this phenomenon by manifestation of three various transitions. The first one manifests water-water interactions, i.e., spanning water network breakdown into small water clusters. It is clearly evidenced by additional normalization to the water content. The second effect corresponds to polymer-water interactions, i.e., breakdown of water cages surrounded methoxy groups of MC. The last one is related to the polymer-polymer interactions, i.e., fibril hydrophobic domain formation. Not only did these results clarify the MC crosslinking mechanism, but also in the future will help to assess MC relevance for various potential application fields.

Keywords: DSC; crosslinking; methylcellulose; thermosensitive hydrogel.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
DSC scans registered during: (a) heating and (b) cooling for solutions of MC at mass content as indicated, normalized to MC mass. Curves shifted in Y-axis for clearness.
Figure 2
Figure 2
Deconvolution of the peaks seen on the scans registered for MC content: (a) 1 wt%, (b) 3 wt%, (c) 9 wt% during heating, and (d) 1 wt% during cooling.
Figure 3
Figure 3
Total transition heat determined during heating and cooling: (a) normalized to the sample mass, (b) normalized to the MC content mass.
Figure 4
Figure 4
Deconvolution results for heating scans as a function of MC content: (a) peaks’ temperature position and (b) peak’s transition heat normalized to sample mass (c) peaks’ width FWHM, (d) peak’s heat normalized to H2O (LT peak) and MC content (MT and HT peaks). Green points in (b) are LT peak area values excluded from the trend analysis due to high deviation.
Figure 5
Figure 5
Deconvolution results for cooling scans as a function of MC content: (a) peaks’ temperature position, (b) peak’s transition heat normalized to sample mass, (c) peaks’ full with at half maximum, (d) peak’s heat normalized to MC mass.

Similar articles

Cited by

References

    1. Niemczyk-Soczynska B., Dulnik J., Jeznach O., Kolbuk D., Sajkiewicz P. Shortening of electrospun PLLA fibers by ultrasonication. Micron. 2021;145:103066. doi: 10.1016/j.micron.2021.103066. - DOI - PubMed
    1. Galaev I.Y., Mattiasson B. ‘Smart’polymers and what they could do in biotechnology and medicine. Trends Biotechnol. 1999;17:335. doi: 10.1016/S0167-7799(99)01345-1. - DOI - PubMed
    1. Qiu Y., Park K. Environment-sensitive hydrogels for drug delivery. Adv. Drug Deliv. Rev. 2001;53:321. doi: 10.1016/S0169-409X(01)00203-4. - DOI - PubMed
    1. Hu J., Meng H., Li G., Ibekwe S.I. A review of stimuli-responsive polymers for smart textile applications. Smart Mater. Struct. 2012;21:053001. doi: 10.1088/0964-1726/21/5/053001. - DOI
    1. Whitcombe M.J., Alexander C., Vulfson E.N. Smart Polymers for the Food Industry. Trends Food Sci. Technol. 1997;8:140. doi: 10.1016/S0924-2244(97)01024-8. - DOI

LinkOut - more resources

-