Viscosity changes of aqueous carboxymethyl starch by partial crosslinking and montmorillonite addition

Nanoarchitectonics for Biodegradable Superabsorbent Based on Carboxymethyl Starch and Chitosan Cross-Linked with Vanillin

Due to the growing demand for sustainable hygiene products (that will exhibit biodegradability and compostability properties), the challenge of developing a superabsorbent polymer that absorbs significant amounts of liquid has been raised so that it can be used in the hygiene sector in the future. The work covers the study of the swelling and dehydration kinetics of hydrogels formed by grafting polymerization of carboxymethyl starch (CMS) and chitosan (Ch). Vanillin (Van) was used as the crosslinking agent. The swelling and dehydration kinetics of the polymers were measured in various solutes including deionized water buffers with pH from 1 to 12 and in aqueous solutions of sodium chloride at 298 and 311 K. The surface morphology and texture properties of the analyzed hydrogels were observed by scanning electron microscopy (SEM). The influence of this structure on swelling and dehydration is discussed. Fourier transform infrared (FTIR) analyses confirmed the interaction between the carboxymethyl starch carbonyl groups and the chitosan amino groups in the resulting hydrogels. Additionally, spectroscopic analyses confirmed the formation of acetal crosslink bridges including vanillin molecules. The chemical dynamics studies revealed that new hydrogel dehydration kinetics strongly depend on the vanillin content. The main significance of the study concerns the positive results of the survey for the new superabsorbent polymer material, coupling high fluid absorbance with biodegradability. The studies on biodegradability indicated that resulting materials show good environmental degradability characteristics and can be considered true biodegradable superabsorbent polymers.

Carboxymethylated starch and cellulose derivatives-based film as human skin equivalent for adhesive properties testing

The films based on carboxymethyl derivatives of starch (CMS) and cellulose (CMC) were proposed as a novel human skin equivalent. The physicochemical properties (moisture absorption, solubility in water, mechanical properties) of CMS/CMC films were evaluated. Additionally, some properties were compared to the human skin ones (surface roughness, tribology). The system based on CMS/CMC 25/75 wt. % was selected for testing the adhesive properties of pressure-sensitive adhesives commonly used for medical purposes (acrylic, silicone and polyisobutylene). Similar tests were performed for human skin. The peel adhesion values for CMS/CMC film and human skin were similar for all adhesives types tested. Applying such a skin equivalent allows to evaluate the functional properties of medical pressure-sensitive adhesives without the ethical and economic issues.

Curcumin-loaded chitosan/carboxymethyl starch/montmorillonite bio-nanocomposite for reduction of dental bacterial biofilm formation

A novel bio nanocomposite of Carboxymethyl Starch (CMS)-Chitosan (CS)-Montmorillonite (MMT) was developed for Curcumin delivery. To improve Curcumin entrapment into Cs-CMS-MMT, different ratios of Chitosan (Cs), Carboxymethyl Starch (CMS) and MMT were used. Particle size and Curcumin entrapment efficiency (EE) were highly affected by different formulation variables. Polysaccharide concentration, Cs-CMS ratio and sonication time had significant effect on particle size. MMT addition enhanced the entrapment efficiency. To optimize entrapment efficiency of Curcumin, statistical analysis was used, and an experiment based on screening design performed with two variants. Morphology and structural characterization of nanocomposite and Curcumin entrapment efficiency were analyzed. The optimal formulation had the average particles size of 35.9nm with Curcumin entrapment efficiency of 91%. Finally, the antibacterial activity of bio nanocomposite against Streptococcus mutans was assessed. Curcumin-loaded bio nanocomposite hindered the formation of biofilm on dental models very effectively.

Enhanced fluoride removal by loading Al/Zr onto carboxymethyl starch sodium: synergistic interactions between Al and Zr

In this paper, a novel type of adsorbent was prepared by loading Al/Zr onto carboxymethyl starch sodium to generate CMS–Al, CMS–Zr or CMS–Al–Zr.