High throughput disassembly of cellulose nanoribbons and colloidal stabilization of gel-like Pickering emulsions

Simultaneous dispersion and gelation of amino group rich nanochitin/carboxylic acid composites for enhanced Pickering emulsion stabilization

To improve suspension properties such as viscosity and stability while minimizing nanochitin dosage, amino group-rich nanochitins were combined with excess carboxylic acids (oxalic and malonic acids) for preparing reinforced Pickering emulsions. The self-assembly of nanochitins was primarily driven by electrostatic interactions between their amino groups and the carboxyl groups of carboxylic acids. At a fixed nanochitin concentration of 0.2 %, the incorporation of oxalic/malonic acids led to a reduction in droplet size and induced gelation in the resulting Pickering emulsions. The acetic acid/nanochitin (AA/DEChN) suspension stabilized emulsions exhibited an average diameter of 6.55 μm, larger than the 4.32 μm observed for oxalic acid/acetic acid/nanochitin (OA/AA/DEChN) systems. Furthermore, while AA/DEChN-stabilized emulsions showed reduced stability during storage, the OA/AA/DEChN systems exhibited demonstrated no signs of creaming. This enhancement mechanism remained effective at higher nanochitin concentrations (0.4 % and 0.5 %), with OA/AA/DEChN-stabilized emulsions achieving average diameters of 2.73 μm and storage moduli of 844.3 Pa at 0.5 % nanochitin.

Thermodynamic insights into the adsorption behaviors of amphoteric cellulose on charged silica surface

This study investigates amphoteric cellulose (AC) adsorption behaviors on the charged silica surface and the associated thermodynamics, a key area with broad industrial relevance. We synthesized a range of ACs with different degrees of substitution (DS) and examined their adsorption on silica using quartz crystal microbalance with dissipation monitoring (QCM-D). By applying Langmuir and Freundlich isotherm models, the maximum adsorption capacity and the interactions between ACs and silica were assessed, and then Van't Hoff equation was employed to estimate the thermodynamic parameters to unveil the mechanisms involved. In terms of ΔG°, ΔH°, and ΔS° associated with the adsorption of AC-0.23 at 298 K were assessed to be -6.68 kJ·mol-1, 18.98 kJ·mol-1, and 85.61 J·mol-1·K-1, respectively. Accordingly, those for AC-0.56 were - 11.21 kJ·mol-1, -10.53 kJ·mol-1, and 1.86 J·mol-1·K-1. These findings underscore the substantial influence of DS on adsorption behavior and thermodynamics of ACs due to the molecular flexibility playing a crucial role in adsorption. The low-charge-density polymer exhibits higher flexibility and entropy-driven adsorption, while the high-charge-density polymer shows stronger electrostatic interactions and more enthalpy-driven adsorption. Our research provides crucial insights into the adsorption behavior of ACs with varying DS, which is essential for enhancing their performance in industrial applications.

Enhanced mechanical properties of cellulose fiber networks through synergistic effects of telechelic-structured carbohydrate-binding module-modified amphoteric polyacrylamide

Mechanical integrity is a pivotal characteristic of cellulose fiber networks; however, their wet strength frequently deteriorates under humid conditions due to the hydrophilic nature of cellulose. This study presents a novel conjugate additive, synthesized by grafting carbohydrate-binding modules onto amphoteric polyacrylamide (CBM3-AmPAM), aimed at enhancing the mechanical properties of cellulose fiber networks at the wet-end of papermaking. The incorporation of CBM3-AmPAM significantly improved performance compared to AmPAM alone, with stress-strain properties enhanced by 1130.34 % and 202.25 % under humid conditions at a 1 % dosage. Notably, the foldability of the cellulose fiber networks increased by 33 %. Employing quartz crystal microbalance with dissipation monitoring (QCM-D), the adsorption behaviors of CBM3, AmPAM, their conjugate (CBM3-AmPAM) and mixture (CBM3+AmPAM) onto fibers were assessed. Results indicated that CBM3-AmPAM exhibited notably robust and more irreversible adsorption compared to other tested formulations. This research highlights the potential of CBM3-AmPAM as an effective wet-end additive in papermaking and provides valuable insights into its interaction with cellulose fibers.

Low-Alpha-Cellulose-Based Membranes

Depending on the method of cellulose production, the proportion of alpha fraction in it can vary significantly. Paper pulp, unlike dissolving cellulose, has an alpha proportion of less than 90%. The presence of cellulose satellites in the system does not impede the formation of concentrated solutions of N-methylmorpholine-N-oxide (NMMO). In the current study, spinning solutions based on cellulose with a low alpha fraction (up to 90%) (pulp cellulose) are investigated. The morphological features and rheological behavior of such solutions are examined. It is suggested to roll the obtained solutions in order to obtain cellulose membranes. X-ray diffraction, IR spectroscopy, AFM and SEM were used to investigate the resulting structure and morphology of the obtained membranes. It is shown that the degree of crystallinity for the membranes varies based on the impurity content in the sample. The morphology of the films is characterized by a dense texture and the absence of vacuoles. The highest strength and elastic modulus were found for membranes made of bleached hardwood sulfate cellulose, 5.7 MPa and 6.4 GPa, respectively. The maximum values of the contact angle (48°) were found for films with a higher proportion of lignin. The presence of lignin in the membranes leads to an increase in rejection for the anionic dyes Orange II and Remazol Brilliant Blue R.

Enhancing cellulose-stabilized multiphase/Pickering emulsions systems: A molecular dynamics perspective

Cellulose stabilized multiphase systems (CSMS) have garnered significant attention due to their ultra-stabilization mechanism and vast potential across different fields. CSMS have found valuable applications in scientific disciplines, including Food Science, Pharmaceutical Science, Material Science, and related fields, owing to their beneficial attributes such as sustainability, safety, renewability, and non-toxicity. Furthermore, MPS exhibit novel characteristics that enable multiple mechanisms to produce HIPEs, aerogels, and oleogels revealing undiscovered information. Therefore, to explore the undiscovered phenomena of MPS, molecular level insights using advanced simulation/computational approaches are essential. The molecular dynamics simulation (MDS), play a valuable role in analyzing the interactions of ternary interphase. The MDS have successfully quantified the interactions of MPS by generating, visualizing, and analyzing trajectories. Through MDS, researchers have explored CSMS at the molecular level and advanced their applications in 3D printing, packaging, preparation, drug delivery, encapsulation, biosensors, electronic devices, biomaterials, and energy conservation. This review highlights the remarkable advancements in CSMS over the past five years, along with contributions of MDS in evaluating the relationships that dictate the functionality and properties of CSMS. By integrating experimental and computational methods, we underscore the potential to innovate and optimize these multiphase systems for groundbreaking applications.

On rheological properties of disc-shaped cellulose nanocrystals

The rheological properties of a substance depend greatly on its morphology, and rod-shaped cellulose nanocrystals (RCNCs) and cellulose nanofibrils (CNFs) have been extensively studied for their rheological properties. Nevertheless, the rheological properties of disc-shaped cellulose nanocrystals (DCNCs) with crystalline allomorph II derived from mercerized cellulose remain unknown yet. This work investigated the DCNCs' rheological properties in depth using steady-shear and oscillation measurements. At the same concentration, DCNC's suspension viscosity is lower than that of RCNC; RCNC has an instinct viscosity of 258.2, while DCNC has 187.9. Comparing RCNC suspensions with cellulose nanorods, DCNC has a lower aspect ratio and exhibits a distinct steady shear behavior. Under polarized film, DCNC suspension cannot self-assemble into chiral or liquid crystal phases, and with increasing concentrations, the system transitions from an isotropic phase to a gel phase. Oscillation sweeps demonstrate that the gel transition occurs at 7 %-8 %. Based on thixotropic recovery sweep outcomes, the high-stress oscillations enhance the network structure of DCNC suspensions, which is significantly different from that of RCNC suspensions. Results demonstrate the unique properties of DCNC, highlighting its application as a rheological modifier.

Innovations in hydrogel-based manufacturing: A comprehensive review of direct ink writing technique for biomedical applications

Direct ink writing (DIW) stands as a pioneering additive manufacturing technique that holds transformative potential in the field of hydrogel fabrication. This innovative approach allows for the precise deposition of hydrogel inks layer by layer, creating complex three-dimensional structures with tailored shapes, sizes, and functionalities. By harnessing the versatility of hydrogels, DIW opens up possibilities for applications spanning from tissue engineering to soft robotics and wearable devices. This comprehensive review investigates DIW as applied to hydrogels and its multifaceted applications. The paper introduces a diverse range of printing techniques while providing a thorough exploration of DIW for hydrogel-based printing. The investigation aims to explain the progress made, challenges faced, and potential trajectories that lie ahead for DIW in hydrogel-based manufacturing. The fundamental principles underlying DIW are carefully examined, specifically focusing on rheological attributes and printing parameters, prompting a comprehensive survey of the wide variety of hydrogel materials. These encompass both natural and synthetic variations, all of which can be effectively harnessed for this purpose. Furthermore, the review explores the latest applications of DIW for hydrogels in biomedical areas, with a primary focus on tissue engineering, wound dressing, and drug delivery systems. The document not only consolidates the existing state of DIW within the context of hydrogel-based manufacturing but also charts potential avenues for further research and innovative breakthroughs.