Alkali and quaternary ammonium cations interact with negatively charged cellulose nanocrystals (CNCs) bearing sulfated or carboxylated functional groups. As these are some of the most commonly occurring cations CNC encounter in applications, the thermodynamic parameters of these CNC-counterion interactions were evaluated with isothermal titration calorimetry (ITC). Whereas the adsorption of monovalent counterions onto CNCs was thermodynamically favourable at all evaluated conditions as indicated by a negative Gibbs free energy, the enthalpic and entropic contributions to the CNC-ion interactions were found to be strongly dependent on the hydration characteristics of the counterion and could be correlated with the potential barrier to water exchange of the respective ions. The adsorption of chaotropic cations onto the surface was exothermic, while the interactions with kosmotropic cations were endothermic and completely entropy-driven. The interactions of CNCs with more bulky quaternary ammonium counterions were more complex, and the mechanism of interaction shifted from electrostatic interactions with surface charged groups of CNCs towards adsorption of alkyl chains onto the CNC hydrophobic planes when the alkyl chain length increased.
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http://dx.doi.org/10.1016/j.carbpol.2024.121949 | DOI Listing |
Anal Chim Acta
February 2025
Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE, Shandong Key Laboratory of Biochemical Analysis, College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao, 266042, China. Electronic address:
Wearable microneedle array (MNA) based electrochemical sensors have gained increasing attention for their capability to analyze biomarkers in the interstitial fluid (ISF), enabling noninvasive, continuous monitoring of health parameters. However, challenges such as nonspecific adsorption of biomolecules on the sensor surfaces and the risk of infection at the microneedle penetration sites hinder their practical application. Herein, a wearable dual-layer microneedle patch was prepared to overcome these issues by integrating an antimicrobial microneedle layer with an antifouling sensing layer.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran.
Oxazolidine is a new category of stimuli-chromic compounds that has unique intelligent behaviors such as halochromism, hydrochromism, solvatochromism, and ionochromism, all of which have potential applications for designing and constructing chemosensors by using functionalized-polymer nanocarriers. Here, the poly(MMA--HEMA) based nanoparticles were synthesized by emulsion copolymerizing methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA) in different copolymer compositions. The poly(MMA--HEMA) based nanoparticles were modified physically with tertiary amine-functionalized oxazolidine (as an intelligent pH-responsive organic dye) to prepare halochromic latex nanoparticles.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Textiles Science and Engineering, Wuhan Textile University, Wuhan 430200, China; State Key Laboratory of New Textile Materials and Advanced Processing Technologies, Wuhan Textile University, Wuhan 430200, China. Electronic address:
Faced with all kinds of serious ecological and environmental protection problems in today's society, development must take the sustainable and green road. Nanocellulose aerogels with the advantages of wide resource of raw materials, low cost, good biocompatibility and biodegradation, are good thermal and sound insulation materials. Herein, a versatile composite aerogel with good thermal stability and heat-insulating property was prepared by freeze-drying method using cellulose nanocrystals (CNCs), waterborne polyurethane (WPU) and sepiolite (SEP) as substrates.
View Article and Find Full Text PDFBiofabrication
January 2025
Division of Engineering, New York University Abu Dhabi, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates, Abu Dhabi, 129188, UNITED ARAB EMIRATES.
Corneal blindness, a leading cause of visual impairment globally, has created a pressing need for alternatives to corneal transplantation due to the severe shortage of donor tissues. In this study, we present a novel interpenetrating network hydrogel composed of gelatin methacryloyl (GelMA) and oxidized carboxymethyl cellulose (OxiCMC) for bioprinting a biomimetic corneal stroma equivalent. We tested different combinations of GelMA and OxiCMC to optimize printability and subsequently evaluated these combinations using rheological studies for gelation and other physical, chemical, and biological properties.
View Article and Find Full Text PDFJ Environ Sci Health A Tox Hazard Subst Environ Eng
January 2025
Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa, Florida, South Africa.
Heavy metal ions are acknowledged to impact the environment and human health adversely. CNCs are effective materials for removing heavy metal ions in industrial applications and process innovations since they can be used in static and dynamic adsorption processes. Cost-effective, uncomplicated water treatment technologies must be developed using biodegradable polymers, namely, modified cellulose nanocrystals.
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