Transparency Properties Research Articles

Biodegradable, UV-blocking, and antioxidant films from alkali-digested lignocellulosic residue fibers of switchgrass

The development of bio-friendly materials to replace single-use plastics is urgently needed. In this regard, cellulosic material from plants is a promising alternative. However, due to the risk of forest depletion, agricultural biomass stands out as a favorable choice. Toward this end, switchgrass, an underutilized grass, presents itself as a viable source of lignocellulose that can be turned into a bio-friendly material. Herein, lignocellulosic residue from switchgrass has been extracted using two different concentrations of NaOH (20% and 50% w/v), solubilized in aqueous ZnCl2 solution, and crosslinked with CaCl2 (200, 300, 400, and 500 mM) to prepare biodegradable films. The color, thickness and moisture, water solubility, water absorption, water vapor permeability, tensile strength and elongation, biodegradation, UV transmittance, and antioxidant activity of films have been studied. The films possess a high tensile strength of 14.7 MPa and elongation of 4.7%. They block UVB-radiation and hold antioxidant properties. They display good water vapor permeability of 1.410–1.6 × 10−11 gm−1s−1Pa−1 and lose over 80% of their weight at 30% soil moisture within 40 days. An increase in the CaCl2 amount decreased the water vapor permeability, elongation, UV transmittance, and biodegradation but increased the transparency, tensile strength and antioxidant property. Overall, films of alkali-digested lignocellulosic residue of switchgrass showed excellent potential to be used against lightweight plastics and support the circular economy.

Development of pH-responsive intelligent films based on κ-carrageenan/straw lignin and anthocyanin from Padus virginiana peel for real-time monitoring of chicken

A series of intelligent films with pH-responsive properties were prepared using Padus virginiana peel extract (PVE) as a smart response factor, κ-carrageenan (κC) as a matrix, and complexed with rice straw lignin (SL). Following the addition of 5 mL PVE at a concentration of 430.99 mg/L, tensile strength and elongation at break of the films increased to a maximum value of 21.25 ± 0.75 MPa and 24.04 ± 0.69 %, respectively. The water vapour permeability of the films decreased with increasing PVE addition, and the minimum value was 5.85 ± 0.09 × 10−11 g m−1 s−1 Pa−1. All the films had favourable thermal stability, transparency, haze and antioxidant properties. PVE-containing films all exhibited excellent pH and ammonia response properties. The higher the humidity of the environment, the faster the ammonia response, and the films were capable of rapid discoloration at 75 % relative humidity. κC/SL-PVE5 can be used to monitor the freshness of chicken breast meat. When the total volatile basic nitrogen of chicken breast meat was increased to 14.27 mg/100 g, κC/SL-PVE5 changed from pink to greyish-yellow. In conclusion, κC/SL-PVE intelligent films hold great promise for real-time monitoring of meat freshness.

Glycerol-driven adaptive evolution for the production of low-molecular-weight Welan gum: Characterization and activity evaluation

Through adaptive laboratory evolution (ALE) of Sphingomonas sp. ATCC 31555, fermentation for production of low-molecular-weight welan gum (LMW-WG) was performed using glycerol as sole carbon source. During ALE, GPC-MALS analysis revealed a gradual decrease in WG molecular weight with the increase of adaptation cycles, accompanied by changes in solution conformation. LMW-WG was purified and structurally analyzed using GPC-MALS, monosaccharide composition analysis, infrared spectroscopy, NMR analysis, atomic force microscopy, and scanning electron microscopy. Subsequently, LMW-WG obtains hydration, transparency, antioxidant activity, and rheological properties. Finally, an in vitro simulation colon reactor was used to evaluate potential prebiotic properties of LMW-WG as dietary fiber. Compared with WG produced using sucrose as substrate, LMW-WG exhibited a fourfold reduction in molecular weight while maintaining moderate viscosity. Structurally, L-Rha nearly completely replaced L-Man. Furthermore, LMW-WG demonstrated excellent hydration, antioxidant activity, and high transparency. It also exhibited resistance to saliva and gastrointestinal digestion, showcasing a favorable colonization effect on Bifidobacterium, making it a promising symbiotic agent.

Sb-doped tin oxide nanonets for improved conductivity in transparent conductive coatings

In light of the three primary challenges faced by transparent conductive coatings, namely poor conductivity, elevated the active substance content, and insufficient visible light transmittance, net-like conductive agents due to the unique morphology and structure have been developed to address these concerns simultaneously. A straightforward synthesis of antimony-doped tin oxide (ATO) nanonets was accomplished through a simple two-step coprecipitation and hydrothermal methods. Firstly, an antimony-doped stannic hydroxide hydrogel precursor was generated through coprecipitation. Secondly, by adjusting the pH value in the hydrothermal reaction, ATO nanocrystals network were obtained without the need for additional materials. The synthesized ATO, with a net-like morphology, comprises particles of approximately 3–5 nm in diameter. Throughout the reaction, ammonium hydroxide, used as a pH regulator, played a vital role as a reducing agent in forming ATO nanonets without the need for further post-treatment. Moreover, net-like ATO compounded with SiO2 transparent conductive coatings exhibited exceptional transparent conductive properties, with a visible-light transmittance of approximately 84.7 % at the wavelength of 550 nm and a square resistance of 0.5 kΩ/sq upon spin-coating deposition on glass. This remarkable performance can be attributed to the generation of a continuous conductive network. In comparison to granular ATO, the network structure ATO nanocrystal showcases a significant improvement in resistivity, demonstrating its exemplary transparent conductivity. The approach for the preparation of ATO nanonets was simple and easy to scale up to provide an enormous potential and broad prospect for the application of net-like ATO in transparent conductive coating.

Enriched oil-in-water emulsions as bioactive agents for locust bean gum films: A comparative investigation

In this study, pracaxi oil (PO) and olive oil (OO) emulsions, enriched with turmeric powder (Cur) and stabilized by nanofribrillated cellulose (NFC), were developed and incorporated to glycerol-plasticized locust bean gum (LBG) dispersions. Films were obtained by solution casting, and their properties were compared, aiming to expand PO application as a potential constituent of active food packaging. The films were characterized for their morphological, structural, transparency, gas permeability, wettability, thermal, mechanical, and antioxidant properties. In relation with the plasticized LBG film, both emulsion films showed improved humidity content, surface wettability, oxygen barrier capacity, thermal stability, and mechanical properties. As for wettability, while the initial water contact angle for the LBG film was θ0 = 93.4°, values of θ0 = 105.5° and θ0 = 99.2° were determined for the LBG films incorporated with PO- and OO-based emulsions, respectively. In comparison with the LBG film, the incorporation of PO-based droplets led to an approximately 8.0% reduction in the water vapor transmission rate values. Also, in comparison with the LBG film, the LBG/NFC/PO-Cur and LBG/NFC/OO-Cur films were capable of reducing the peroxidation value of sunflower oil by 16% and 11%, respectively. Enhancements in tensile strength values of 44% and 49% were determined for the PO- and OO-based emulsion films. The emulsion films presented similar antioxidant properties and better preservation of strawberry model food than LBG and polyethylene films. The results of the comparative experiments suggested that the use of PO may be expanded as a component of active food packaging.

Effect of DC poling on transparency and photoluminescence in Pr:PMN-PT transparent ceramics

Electric poling could significantly influence the transparency and the photoluminescence (PL) intensities in transparent ferroelectric PL ceramics. This work applied direct current (DC) poling on a highly transparent 0.75PMN-0.25PT:0.015Pr3+ ceramic, observed the domain configurations in a direction perpendicular to poling direction. Lamellar domains perpendicular to electric field were observed after poling and decreased the transmittance by changing the propagation path of incident light. Besides, the enhancement of PL intensities by poling was found as high as 62 %, mainly due to the following reasons: the change of light propagation path by the lamellar domains is supposed to increase the absorption of exciting light; and the reduced crystal symmetry may increase the PL efficiency. This work revealed the effects of DC poling on transparency and PL properties in transparent ferroelectric PL ceramics.

One-pot synthesis of copolyamide PA MXDT-MXD6 towards oxygen-barrier and high-temperature transparent applications

Semi-aromatic polyamides have long been recognized for their exceptional comprehensive properties in numerous demanding applications. Among them, poly(m-xylylene adipamide) (MXD6) was commonly used in oxygen-barrier packaging but suffered diminished transparency due to thermal crystallization. Herein, we introduced terephthalic acid (PTA) as rigid monomer units into the chain of MXD6 to prepare amorphous copolyamides PA MXDT-MXD6 via one-pot polycondensation, guided by thermal analysis. The chemical structure of copolyamides was confirmed using 1H NMR and FTIR spectra. Thermal analysis revealed that the copolyamides exhibited high thermal stability, amorphous characteristics, and improved glass transition temperatures (110.9–136.5 °C). Pyrolysis kinetics further demonstrated that copolyamides have enhanced thermal stability and lifetime. Furthermore, copolymerization resulted in numerous amide bonds conjugated with benzene rings, leading to superior high-temperature transparency, oxygen-barrier, and mechanical properties compared to MXD6 and other reference polyamides. These characteristics indicate the potential suitability of copolyamides as transparent and heat-resistant barrier materials.

Spin coated ultrathin PEDOT:PSS/SWCNT film with high electronic conductivity

Conductive Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been extensively used as non-metallic electrodes. However, the relatively low electrical conductivity of pristine PEDOT:PSS film restricts its further application. Although doping high content conductive filler or increasing the film thickness are effective for enhancing the electrical property, the transparency is sacrificed, which limits the application of PEDOT:PSS films. In this study, preparing PEDOT:PSS composite film with highly conductive and transparent property was the primary purpose. To achieve this goal, single-walled carbon nanotubes (SWCNTs) and dimethyl sulfoxide (DMSO) was chosen to composite with PEDOT:PSS. The spin-coated SWCNT/PEDOT:PSS composite film exhibited excellent electrical conductivity and transparency. The electrical conductivity of composite film with desired transmittance property (78%) reached the highest value (1060.96 S cm−1) at the SWCNTs content was 6 wt%. Under the modification process applied in this work, the non-conductive PSS was partially removed by incorporated DMSO and SWCNTs. Then, the molecular chains of PEDOT stretched and adsorbed onto the surface of SWCNTs, forming a highly efficient three-dimensional conductive structure, which contributed to the enhancement of electrical conductivity and transparency. Additionally, the spin-coating process allowed for the reduction of film thickness, ensuring better transparency. This research contributed to expanding the further applications of PEDOT:PSS films in high-performance transparent film electrodes.

Nickel‐ and Palladium‐Catalyzed Copolymerizations of Norbornene with Polar α‐Olefins

AbstractRecent progress regarding the copolymerization of norbornene with various polar α‐olefins catalyzed by nickel and palladium catalysts is reviewed here with special attention paid to the diverse catalyst frameworks, polar monomer scopes as well as polymer microstructures. Both the influences of steric effect and electron property of ligand substituents and the type of polar monomers on the catalytic behaviors (activity, stability, polarity tolerance, etc.) and the polymer microstructures (molecular weight and distribution, comonomer contents, etc.) have been summarized. The introduction of noncyclic‐olefins, such as polar vinyl monomers, polar higher α‐olefins, and polar styrenes, into rigid cyclic‐based polynorbornene chain resulted in significant modifications on the polarity, compatibility, thermostability, processibility, transparency, and many other properties of the material, which has also been discussed in the review. The contents of this review have been classified according to the type of polar monomers involved in the norbornene copolymerization, and each section included nickel and palladium catalysts bearing different ligand structures, which will be meaningful for the development of new types of catalysts and new families of norbornene‐based cyclic olefin copolymer materials in the future.

Sustainable, transparent, strong toughness, UV resistance, and anti-corrosion properties of cashew shell oil-based waterborne polyurethane network derived from phloretin and sorbitan monooleate-based siloxane

The increasingly severe energy shortage and growing environmental problems have accelerated the rapid development of sustainable polymer materials. Hereon, a novel method was proposed for the synthesis of cashew nut shell oil-based waterborne polyurethane (WPUs), which exhibited excellent toughness, transparency, water resistance, UV resistance and corrosion resistance. Specifically, the sorbitan monooleate-based siloxane (MSP) was prepared via a thiol-ene click chemistry reaction. Subsequently, the plant-based phloretin (PRT) and MSP were introduced as polyols into the skeleton of WPUs through the molecular structure design strategy. Series of high bio-based content (91 %) WPUs networks were obtained via pre-polymerization and self-emulsification methods. The properties of their dispersions and films were thoroughly investigated, and it was found that the addition of MSP and PRT enhanced the overall performance of WPUs film. For instance, there was a significant increase in Tg. Additionally, they exhibited a maximum tensile strength of 31.5 MPa and a maximum toughness of 53 MJ/m3, which were the most outstanding among all reported plant oil-based WPU systems so far, indicating excellent tear resistance. Interestingly, the water absorption rate of PSWPU-40 was reduced to 7.1 %, suggesting good water resistance, which resolved the contradiction between the mechanical properties and water resistance of the current plant oil-based WPU systems. The PSPWU films exhibited promising application prospects, exemplified by its ability to effectively shield the entire UV range. Furthermore, its coating demonstrated outstanding anti-corrosion properties with a maximum anticorrosion efficiency of 97.1 %. It could be attributed to the synergistic effect of a self-crosslinking structure, higher crosslinking density, a tighter network structure, and stronger intermolecular forces (H-bond). This work provided a meaningful guide for the application and development of high-performance bio-based WPU functional coatings.

Noncontact Microfluidics of Highly Viscous Liquids for Accurate Self-Splitting and Pipetting.

Accurate dosing for various liquids, especially for highly viscous liquids, is fundamental in wide-ranging from molecular crosslinking to material processing. Despite droppers or pipettes being widely used as pipetting devices, they are powerless for quantificationally splitting and dosing highly viscous liquids (>100mPa s) like polymer liquids due to the intertwined macromolecular chains and strong cohesion energy. Here, a highly transparent photopyroelectric slippery (PS) platform is provided to achieve noncontact self-splitting for liquids with viscosity as high as 15000mPa s, just with the assistance of sunlight and a cooling source to provide a local temperature difference (ΔT). Moreover, to guarantee the accuracy for pipetting liquids (>80%), the ultrathin MXene film (within a thickness of 20nm) is self-assembled as the photo-thermal layers, overcoming the trade-off between transparency and photothermal property. Compared with traditional pipetting strategies (≈1.3% accuracy for pipetting polymer liquids), this accurate microfluidic chip shows great potential in adhesive systems (bonding strength, twice than using the droppers or pipettes).

Selectively controlling the surface adhesion of highly transparent polymer thin films through thermoactivated cavitation of interface-assembled gas-blasting nanocapsules

Transparent polymer thin films have received increasing attention as functional optical materials for sunlight control and are widely used in applications ranging from photovoltaic solar cells to flexible display devices. Because various types of film defects may occur during the thin film process, a clean separation technology for the recovery of valuable core components is crucial for sustainable engineering but remains challenging. Herein, we report an effective and scalable method for selectively controlling the surface adhesion of highly transparent polymer thin films using the thermoactivated cavitation of interface-assembled gas-blasting nanocapsules. The synthesized nanocapsules, comprising poly(acrylonitrile-co-methyl methacrylate) as a polymer shell layer and benzenesulfonyl hydrazide as a gas-generating core material, were uniformly mixed with ultraviolet-curable resins and applied as a surface adhesion-controllable layer between the substrate and transparent polymer thin film. This interface-assembled gas-blasting nanocapsule layer can form N2-gas microbubbles at the interface between the substrate and thin film upon heating, enabling the large-area and flawless separation of transparent thin films with a tremendous reduction in the surface adhesion strength. Furthermore, the interfacial adhesion of highly transparent thin films was effectively controlled by optimizing the heat treatment process without affecting their optical transparency or intrinsic adhesive properties.

Morphological, Thermal, Physicomechanical and Optical Properties of Crosslinked Poly (Ester-Urethane-Acrylate): Effect of Added Methyl Methacrylate

Poly (ester-urethane-acrylate) (PEUA) macromonomer was prepared by reacting two moles of isophorone diisocyanate (IPDI) with one mole of bis (1,4-butanediol ortho-phthalate) (BPE), followed by end-capping with two moles of 2-hydroxyethyl methacrylate (HEMA) in the presence of dibutyltin dilaurate (DBTDL) catalyst. Thereafter, different ratios of methyl-methacrylate (MMA) were added to the PEUA macromonomer to prepare crosslinked PEUA/MMA sheets. Fourier transform infrared spectrometry (FTIR), ultraviolet-visible spectrophotometry (UV-vis) and differential scanning calorimetry (DSC) techniques were employed to investigate the structure, optical transparency and thermal properties of the crosslinked sheets. The effect of MMA on the polymerization shrinkage and abrasive wear properties of PEUA and their copolymers were also studied. The polymerization shrinkage study showed that PEUA copolymer containing 40 wt% MMA had a more rigid microstructure with improved volume shrinkage and abrasive wear properties as compared with the other compositions of PEUA copolymers with MMA loadings of 80, 60 and 20%. The improvement was attributed to the better miscibility and compatibility of 40 wt% MMA with the PEUA as revealed by DSC, heat deflection temperature (HDT) and scanning electron microscope (SEM) studies.

Aqueous Dispersion of Aramid Nanofibers Achieved by Using Tannic Acid for Ultrahigh Strength Films.

Polymer nanofibers have established a robust foundation and possess immense potential in various emerging fields such as sensors and biotechnology. In this study, aqueous dispersions of aramid nanofibers (ANFs) were successfully prepared by using tannic acid (TA). Morphological analysis revealed that TA effectively prevented self-aggregation of ANFs, and preserved the nanofiber structure during TA-assisted solvent exchange. Subsequently, the ANF and TA/ANF films were fabricated using casting and vacuum-assisted filtration techniques. Notably, the tensile strength of the casting TA/ANF film reached 393.8 MPa, exhibiting a remarkable improvement of 41.3% compared to that of the pure ANF film. These exceptional mechanical properties can be attributed to the well-dispersed nanostructures, hydrogen-bonding interactions, zigzag structures, and fiber-bridging effects. Furthermore, the TA/ANF film demonstrated superior ultraviolet (UV) shielding capabilities, visible transparency properties, and excellent resistance to chemical reagents. The above-mentioned interesting findings demonstrate its potential as a nanofiber-reinforced material for poly(vinyl alcohol) (PVA) composites.

Green Synthesis, Hybridization of SiO<sub>2</sub> by Alkaline -Acid Leaching Method and their Optical and Structural Properties Using Rice Husk and <i>Anogeissus leiocarpus</i> Extract

Silicon oxide is widely used as a thin film to improve the surface properties of materials, because it is of anti-resistance, hardness, corrosion resistance, dielectric, optical transparency and high delivery property etc. Therefore. Recent growing interest and efforts of scientists in this area are due to vitality in achievement of a better quality of life and health care for human beings, designing novel methods of making them more effective through hybridization with silver nanoparticles. Hence the need for nanoparticles capable of transmitting light with an ‘enhanced’ optical property for optoelectronics. In this study, silica was extracted from rice husk ash (RHA) using alkaline/acid leaching method, the AgNps was synthesized from Anogeissus leiocarpus extract using water extraction process, while the hybridization of silica with AgNps was carried out using in-situ and co-mixing method. Characterization was achieved using UV-Visible to confirmed the presence of silica at 290 nm, 291 nm, and 295 nm at different time intervals of 0, 60, 90. Changes in intensities of the bands indicate perfect hybridization with an enhancement in optical property. The XRD pattern of the silica-silver nanoparticles showed crystalline peaks at 2θ = 22.0o, 26.5o,29.5o 41o, which have been keenly indexed as face centred cubic Ago nanocrystals arising from Anogeissus leiocarpus extract. The increase in absorbance value of silica from (0.5 to 1.45, 1.50 respectively) confirms the improvement in optical properties of silica due to presence of AgNPs. The SEM analysis revealed the cap shaped spherical morphology and uniform size distribution of the nanohybrids within the range of 18.20 nm. Capping obtained is an evidence of organic matter in the plant extract. The percentage elemental compositions of Ag, Si, C and O in the nanohybrids were revealed by EDX analysis where Ag and Si are dominant. Therefore, silica-silver nanocomposite can be used as improved raw material in optical, ceramics and other relevant industries.

Ultraviolet light blocking optically clear adhesives for foldable displays via highly efficient visible-light curing

In developing an organic light-emitting diode (OLED) panel for a foldable smartphone (specifically, a color filter on encapsulation) aimed at reducing power consumption, the use of a new optically clear adhesive (OCA) that blocks UV light was crucial. However, the incorporation of a UV-blocking agent within the OCA presented a challenge, as it restricted the traditional UV-curing methods commonly used in the manufacturing process. Although a visible-light curing technique for producing UV-blocking OCA was proposed, its slow curing speed posed a barrier to commercialization. Our study introduces a highly efficient photo-initiating system (PIS) for the rapid production of UV-blocking OCAs utilizing visible light. We have carefully selected the photocatalyst (PC) to minimize electron and energy transfer to UV-blocking agents and have chosen co-initiators that allow for faster electron transfer and more rapid PC regeneration compared to previously established amine-based co-initiators. This advancement enabled a tenfold increase in the production speed of UV-blocking OCAs, while maintaining their essential protective, transparent, and flexible properties. When applied to OLED devices, this OCA demonstrated UV protection, suggesting its potential for broader application in the safeguarding of various smart devices.

Development of slow release antibacterial polylactic acid bilayer active film with different distributions of clove essential oil and its application for snakehead (Channa argus) preservation

The antibacterial polylactic acid (PLA) bilayer active films with slow release property were developed by utilizing the different distributions of clove essential oil (CEO) in two layers. The effect of CEO different distribution on the films' properties and their application in snakehead packaging were studied. The FTIR spectra and SEM indicated that CEO was successfully incorporated into the PLA films. The incorporation of CEO enhanced tensile strength, gas barrier properties of the films and provided the films with UV resistance, good antibacterial and antioxidant activities. The different distributions of CEO didn't significantly affect the color, transparency, and gas barrier properties of the films. But they influenced the mechanical properties, recovery rate of CEO and the release behavior, showing that the film with higher unilateral CEO exhibited higher tensile strength, bigger elongation at break and higher loss of CEO. The film with higher CEO in outer layer released CEO more slowly into food simulant (10% ethanol). This was also reflected by their different antibacterial and antioxidant activities of the films due to the different distributions of CEO. The films containing CEO could efficiently inhibit the microorganism's growth and the protein decomposition of snakehead during storage. The snakehead packed by the film containing 4% CEO in outer layer and 2% CEO in inner layer exhibited the best quality stability. The concept of this work showed great potential in developing slow release active films for food packaging.

Optimization of transparent conductive properties of magnetron sputtered Sb-doped SnO2 films by RF power: Towards application in polymer-dispersed liquid crystal (PDLC) films

Sb-doped SnO2 (ATO) films were prepared with different RF powers (PRF) under two O2 flow rates (FO2) by magnetron sputtering, and then subjected to rapid thermal annealing (RTA) treatment. The effects of PRF, FO2, and RTA on the crystallinity, stress, surface morphology, conductive properties, transmittance in visible-light range (TVis), and energy gap (Eg) of the films were investigated. As the PRF increases, the film crystallinity improves or first improves and then slightly degrades, and the compressive stress decreases. With increasing PRF, the surface changes from textured to granular morphology and from granular to honeycomb-like morphology under two FO2, respectively. Meanwhile, the conductive properties first enhance and then degrade, and the TVis and Eg tend to decrease, especially at higher PRF. Basically, the films prepared with higher FO2 have lower compressive stress, inferior conductive properties, and larger TVis and Eg compared with the films prepared with lower FO2. After RTA, the film crystallinity obviously improves, the compressive stress transforms into tensile stress, and the surface morphology has not undergone significant changes. Meanwhile, the conductive properties significantly enhance and Eg obviously increases. The TVis of the films prepared with lower FO2 can be increased by RTA. The influence mechanisms of the above factors on the structure and optoelectronic properties of the ATO films were explored, and ultimately, the ATO films have the TVis of 76.35–80.86%, sheet resistance of 51.7–91.9 Ω/sq., and quality factor of 1.03–1.67 × 10−3 Ω−1 within the optimized PRF range. Polymer-dispersed liquid crystal (PDLC) films were fabricated using optimized performance ATO films as electrodes, and their on-state transmittance, off-state transmittance, threshold electric field, and saturation electric field were 2.08–4.61%, 61.69–68.56%, 0.656–0.796 V/μm, and 1.68–2.108 V/μm, respectively. The current results indicate the potential application of ATO films in PDLC films as electrode.

Process-structure-property relationships of cellulose nanocrystals derived from Juncus effusus stems on ҡ-carrageenan-based bio-nanocomposite films

This study investigates the potential of Juncus plant fibers as a renewable source for producing cellulose nanocrystals (CNs) to reinforce polymers. Cellulose microfibers (CMFs) were extracted with a 0.43 ± 0.2 μm diameter and 69 % crystallinity through alkaline and bleaching treatments, then subjected to sulfuric acid hydrolysis, yielding four CN types (CN10, CN15, CN20 and CN30) with distinct physico-chemical properties and aspect ratios (47, 55, 57, and 60). The study assessed the influence of cellulose nanocrystals (CNs), incorporated at different weight percentages (3 %, 5 %, and 8 %), on thermal, transparency, and mechanical properties in k-carrageenan (CA) biocomposite films. The results indicate significant enhancements in these characteristics, highlighting good compatibility between CNs and CA matrix. Particularly noteworthy is the observed substantial improvement in tensile strength at an 8 wt% loading, with values of 23.43 ± 0.83 MPa for neat CA, 33.53 ± 0.83 MPa for CA-CN10, 36.67 ± 0.71 MPa for CA-CN15, 37.65 ± 0.56 MPa for CA-CN20, and 39.89 ± 0.77 MPa for CA-CN30 composites. Furthermore, the research explores the connection between the duration of hydrolysis and the properties of cellulose nanocrystals (CNs), unveiling their influence on the characteristics of nanocomposite films. Prolonged hydrolysis enhances CN crystallinity (CrI), aspect ratio, and surface charge content, consequently enhancing mechanical features like strength and flexibility in these films. These findings demonstrate the potential of Juncus plant fibers as a natural and eco-friendly resource for producing CNs that effectively reinforce polymers, making them an attractive option for diverse applications in the field.

Formation of gel and solid phases in acrylic cuvettes upon exposure to DMSO, oxygen and light: implications for fluorescence spectroscopy

We here report the formation of a turbid-gel phase in acrylic cuvettes upon exposure to pure Dimethyl Sulfoxide (DMSO) at room temperature. The observed phenomenon occurred over a 10 h to 14 h incubation in the presence of environmental oxygen. After the turbid gel was removed from the cuvette, it became a white solid exhibiting unique emission behavior. The formation of the turbid-gel phase was accelerated upon exposure to UV 295 LED pulses of light from 6 h to 8 h. Surprisingly, subsequent exposure of the white solid to a few microliters of pure DMSO and vortexing resulted in its transformation into a transparent gel state in just a few minutes, eventually acquiring transparent and liquid properties. Additionally, the white-solid phase can load other molecules, such as Resveratrol and Quercetin, leading to shifts in the respective emission spectra compared with the same molecule in liquid and pure DMSO. These novel findings highlight the interaction between UV photons, oxygen, DMSO and Acrylic, and potentially distort fluorescence spectroscopy experiments.