Effect Of Crosslinking Research Articles

Effect on thermal, mechanical, and biodegradable properties of plasma‐treated fish scale powder/linear low‐density polyethylene polymer composite films

AbstractIn the present work, we report the effect of low‐temperature plasma treatment on thermal, mechanical, and biodegradable properties of polymer composite blown films prepared from carp fish scale powder (CFSP) and linear low‐density polyethylene (LLDPE). The CFSP was melt compounded with LLDPE using a filament extruder to prepare 1, 2, and 3 wt.% of CFSP in LLDPE polymer composite filaments. These filaments were further pelletized and extruded into blown films. The blown films extruded with 1, 2, and 3 wt.% of CFSP in LLDPE were tested for thermal and mechanical properties. It was observed that the tensile strength decreased with the increased loading content of CFSP, and 1% CFSP/LLDPE exhibited the highest tensile strength. To study the effect of low‐temperature plasma treatment, 1% CFSP/LLDP polymer composite with high tensile strength was plasma treated with O2 and SF6 gas before blow film extrusion. The 1% CFSP/LLDPE/SF6‐extruded blown films showed increased thermal decomposition, crystallinity, tensile strength, and modulus. This may be due to the effect of crosslinking by the plasma treatment. The maximum thermal decomposition rate, crystallinity %, tensile strength, and modulus obtained for 1% CFSP/LLDPE/SF6 film were 500.02°C, 35.79, 6.32 MPa, and 0.023 GPa, respectively. Furthermore, the biodegradability study on CFSP/LLDPE films buried in natural soil for 90 days was analyzed using x‐ray fluorescence. The study showed an increase in phosphorus and calcium mass percent in the soil. This is due to the decomposition of the hydroxyapatite present in the CFSP/LLDPE biocomposite.

Fabrication of Highly Efficient and Ambient Stable Planar MAPbI3 Perovskite Solar Cells via Defect Passivation through Crosslinking Strategy

Iodine‐based hybrid planar perovskite solar cells’ (PSCs) overall performance is still very limited. In this work, a highly functionalized iodine‐based hybrid perovskite layer is fabricated by incorporating trimethylolpropane ethoxylated triacrylate (TET) within the perovskite precursor, which can crosslink with the grain boundaries to improve the crystallinity as well as the grain size and passivate the defect states of the perovskite material. The MAPbI3‐based thin films with TET exhibited large grain sizes from 195.73 to 587.49 nm with 8 mg mL−1 of TET concentration. The X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X‐ray (EDX) elemental mapping, photoluminescence (PL), and time resolved photoluminescence (TRPL) characterization results suggest the strong crosslinking effect between TET and MAPbI3, which improves the crystallinity and reduces the charge trap density. Planar PSCs is fabricated with the device architecture fluorine‐doped tin oxide (FTO)/c‐TiO2/MAPbI3:TET/Spiro‐MeOTAD/Au and achieved a power conversion efficiency (PCE) of 14.75% under 1.5 AM light illumination. The fabricated PSCs shows excellent ambient stability which retains 80% of their PCE after being exposed to the ambient environment of relative humidity (RH) ≈60%, room temperature (RT) ≈27 °C without any encapsulation.

Strong and tough poly(vinyl alcohol)/xanthan gum-based ionic conducting hydrogel enabled through the synergistic effect of ion cross-linking and salting out

The mechanical properties of ionic conductive hydrogels (ICHs) are generally inadequate, leading to their susceptibility to breakage under external forces and consequently resulting in the failure of flexible electronic devices. In this work, a simple and convenient strategy was proposed based on the synergistic effect of ion cross-linking and salting out, in which the hydrogels consisting of polyvinyl alcohol (PVA) and xanthan gum (XG) were immersed in zinc sulfate (ZnSO4) solution to obtain ICHs with exceptional mechanical properties. The salt-out effects between PVA chains and SO42− ions along with the cross-linked network of XG chains and Zn2+ ions contribute to the desirable mechanical properties of ICHs. Notably, the mechanical properties of ICHs can be adjusted by changing the concentration of ZnSO4 solution. Consequently, the optimum fracture stress and the fracture energy can reach 3.38 MPa and 12.13 KJ m−2, respectively. Moreover, the ICHs demonstrated a favorable sensitivity (up to 2.05) when utilized as a strain sensor, exhibiting an accurate detection of human body movements across various amplitudes.

Effect of carbonyl-amino condensation, non-covalent cross-linking and conformational changes induced by ultrasound-assisted Maillard reaction on lysinoalanine formation in silkworm pupa protein

The inhibition of cross-linked lysinoalanine (LAL) formation in silkworm pupa protein isolates (SPPI) by Maillard reaction (using varying xylose concentration) and ultrasound treatment was studied. Results showed that sonicated SPPI was effectively grafted with high concentration of xylose (5 %), resulting in the lowest LAL content, which was 48.75 % and 30.64 % lower than the control and ultrasound-treated samples, respectively. Chemical bond analysis showed that the combined treatment destroyed the ionic bonds, intrachain (g-g-t), and interchain (g-g-g) disulfide bonds, but stimulated the polymerization of hydrogen and hydrophobic bonds between SPPI and xylose, and as well enhanced the net negative charge between SPPI/Xylose complexes. The particles of the complexes were more loose, dispersed and rough, and had a stronger hydrophilic microenvironment, accompanied by alterations in microscopic, secondary and tertiary structures. Ultrasound treatment induced the breakdown of the oxidative cross-linking in SPPI, and promoted the sulfhydryl group-dehydroalanine binding and the carbonyl-amino condensation of the protein and xylose, and thus inhibited the formation of cross-linked LAL. Furthermore, the physicochemical and structural parameters were highly interrelated with cross-linked LAL content (|r| > 0.9). The outcomes provided a novel avenue and theoretical basis for minimizing LAL formation in SPPI and improving the nutrition and safety of SPPI.

Investigating the influence of collagen cross-linking on mechanical properties of thoracic aortic tissue.

Vascular diseases, such as abdominal aortic aneurysms, are associated with tissue degeneration of the aortic wall, resulting in variations in mechanical properties, such as tissue ultimate stress and a high slope. Variations in the mechanical properties of tissues may be associated with an increase in the number of collagen cross-links. Understanding the effect of collagen cross-linking on tissue mechanical properties can significantly aid in predicting diseased aortic tissue rupture and improve the clarity of decisions regarding surgical procedures. Therefore, this study focused on increasing the density of the aortic tissue through cross-linking and investigating the mechanical properties of the thoracic aortic tissue in relation to density. Uniaxial tensile tests were conducted on the porcine thoracic aorta in four test regions (anterior, posterior, distal, and proximal), two loading directions (circumferential and longitudinal), and density increase rates (0%-12%). As a result, the PPC (Posterior/Proximal/Circumferential) group experienced a higher ultimate stress than the PDC (Posterior/Distal/Circumferential) group. However, this relationship reversed when the specimen density exceeded 3%. In addition, the ultimate stress of the ADC (Anterior/Distal/Circumferential) and PPC group was greater than that of the APC (Anterior/Proximal/Circumferential) group, while these findings were reversed when the specimen density exceeded 6% and 9%, respectively. Finally, the high slope of the PDL (Posterior/Distal/Longitudinal) group was lower than that of the ADL (Anterior/Distal/Longitudinal) group, but the high slope of the PDL group appeared larger due to the stabilization treatment. This highlights the potential impact of density variations on the mechanical properties of specific specimen groups.

Chitosan-Based Hierarchical Scaffolds Crosslinked with Genipin

Osteochondral defects present significant challenges for effective tissue regeneration due to the complex composition of bone and cartilage. To address this challenge, this study presents the fabrication of hierarchical scaffolds combining chitosan/β-tricalcium phosphate (β-TCP) to simulate a bone-like layer, interconnected with a silk fibroin layer to mimic cartilage, thus replicating the cartilage-like layer to mimic the native osteochondral tissue architecture. The scaffolds were produced by freeze-drying and then crosslinking with genipin. They have a crosslinking degree of up to 24%, which promotes a structural rearrangement and improved connection between the different layers. Micro-CT analysis demonstrated that the structures have distinct porosity values on their top layer (up to 84%), interface (up to 65%), and bottom layer (up to 77%) and are dependent on the concentration of β-tricalcium phosphate used. Both layers were confirmed to be clearly defined by the distribution of the components throughout the constructs, showing adequate mechanical properties for biomedical use. The scaffolds exhibited lower weight loss (up to 7%, 15 days) after enzymatic degradation due to the combined effects of genipin crosslinking and β-TCP incorporation. In vitro studies showed that the constructs supported ATDC5 chondrocyte-like cells and MC3T3 osteoblast-like cells in duo culture conditions, providing a suitable environment for cell adhesion and proliferation for up to 14 days. Overall, the physicochemical properties and biological results of the developed chitosan/β-tricalcium phosphate/silk fibroin bilayered scaffolds suggest that they may be potential candidates for osteochondral tissue strategies.

Evolution of the structure and tribological behavior of the organic coatings under gamma-ray irradiation

More reliable and long-term irradiation stability is essential for lubrication protection materials that served in nuclear energy equipment. In this paper, three typical commercially organic bonded solid lubricating coatings were chosen to investigate the influence of gamma (γ)-ray irradiation on microstructure and tribological behaviors. The evolution of microstructure and the changes of tribological properties for these coatings after irradiation were comparatively studied in detail. The results revealed that the crystallinity of the molybdenum disulfide (MoS2) lubricating phase was improved and were partial oxidized in the coatings after γ-ray irradiation, resulting in the surface roughness of the coating with MoS2 as the solid lubricating phase decreased significantly. The polytetrafluoroethylene (PTFE) lubricating phase was degraded from the long chains structure to smaller molecules after γ-ray irradiation. The results of tribological properties of the three coatings after γ-ray irradiation indicated that, for polyamide-imide-based lubricating coatings, the friction coefficient is decreased and the wear rate is increased after irradiation. For phenolic epoxy-based lubricating coating, the cross-linking effect of γ-ray irradiation predominated to improve the wear resistance and prolong the wear life of the coating. But overall, the influence of irradiation on tribological properties of three polymer-based coatings could almost be neglected duo to the changes of the microstructure in nanoscale. This work provides path and direction for design and preparation of the lubricating coatings that served in a nuclear reactor.

Using bacterial cellulose to bridge covalent and physical crosslinks in hydrogels for fabricating multimodal sensors

Network optimization is vital for the polysaccharide based hydrogels with multiple crosslinks. In this study, we developed a ‘two-step’ strategy to activate synergistic effect of chemical and physical crosslinks using a poly (vinyl alcohol) (PVA)/bacterial cellulose (BC) hydrogel as a template. The BC nanofibers, on the one hand, acted as nucleating agents, participating in the crystallization of PVA, and on the other hand, were also involved in the formation of boronic ester bond, anchored with the PVA chains via chemical bonding. Therefore, the existence of BC nanofibers, as ‘bridge’, linked the crystalline regions and amorphous parts of PVA together, associating the two characteristic crosslinks, which was conducive to load transfer. The mechanical properties of resultant hydrogels, including the tensile elongation and strength, as well as fracture toughness, were significantly improved. Moreover, the dually cross-linked hydrogels possessed ionic conductivity, which was sensitive to the tensile deformation and environmental temperature. This study clarifies a unique role of BC nanofibers in hydrogels, and proposes an effective approach to construct multiple networks in the nanocellulose reinforced PVA hydrogels.

Open-system force-elongation relationship of collagen in chemo-mechanical equilibrium with water

A significant deformation mechanism of collagen at low loads is molecular uncoiling and rearrangement. Although the effect of hydration and cross-linking has been investigated at larger loads when collagen undergoes molecular sliding, their effects on collagen molecular reorganization remain unclear. Here we develop two thermodynamic models that use the notion of open-system elasticity to elucidate the effect of swelling due to water uptake during deformation of collagen networks under low and high cross-linking conditions. With low crosslinking, entropic contributions dominate resulting in rejection of solvent from the polymer network leading to reduced collagen stiffness with increased loads. Contrarily, high cross-linking inhibits initial coiling and structural kinking and the mechanical behavior is dominated by elastic energy. In this configuration, the solvent content depends on the sign of the applied load resulting in a non-linear open-system stress-strain relationship. The models provide insight on the parameters that impact the stress-strain relationships of hydrated collagen and can inform the way collagenous matrices are treated both in medical and laboratory settings.

Chitosan silver nanoparticle inspired seaweed (Gracilaria crassa) biodegradable films for seafood packaging

As an alternative to conventional plastic packaging, the concept of developing blend films with bio-based materials seems to be an environmentally friendly approach. In the present study, blend films were prepared using ethanolic extract of Gracilaria crassa (GCE) with chitosan (CS) and silver nanoparticles (AgNPs). The developed films were evaluated based on the physical, mechanical, structural, barrier and antioxidant indices. The films were slightly yellowish in color (b* ranges 39.69–53.08) and smooth textured. The FTIR spectra confirmed the intermolecular interaction between film components and the combination of CS and GCE occurred by means of -OH groups and hydrophobic interaction due to the cross-linking effect of the plasticizer (glycerol). The antioxidant properties of the films were investigated via DPPH assay and total phenolic contents showed significant improvement (p < 0.05) upon incorporation of GCE. Similar observations were made for tensile parameter (37.29 ± 1.22–38.39 ± 1.09) compared to the control (29.71 ± 1.66). The thermal pattern of blended films showed greater stability with Tg of 112.6 °C. The formulated films significantly extended the shelf-life of shrimp nuggets in refrigerated storage (4 °C) up to 9 days. The study reveals that the incorporation of GCE/AgNPs with chitosan films can be an active packaging system in the field of sustainable food packaging technology.

Transglutaminase-induced Cornea Collagen Crosslinking Effect on Central Corneal Thickness and Keratocyte Cell Density

Abstract&#x0D; Introduction &amp; Objectives : This research is aimed to evaluate the effect of transglutaminase-induced corneal collagen crosslinking (CXL) on central corneal thickness (CCT) and keratocyte cell density in vivo.&#x0D; Methods : Twenty-eight white New Zealand rabbits were divided into four groups: the transglutaminase- induced CXL group, the epithelial-off CXL group, the transepithelial CXL group, and the control group. The ocular surface was treated with a 1 U/mL microbial transglutaminase solution, and both the epithelial-off and transepithelial groups were exposed to clinical ultraviolet A-riboflavin (UVA/RF). The efficacy of each group was evaluated on the 14th day after the procedures. Central corneal thickness was evaluated with Corneal Visualization Scheimpflug Technology (Corvis ST) and keratocyte cell density wad evaluated with histopathology examination.&#x0D; Results : Transglutaminase-induced CXL group exhibited the highest mean biomechanical CCT (370.14 ± 38.85) in comparison to the UVA/RF epithelial-off group (368.00 ± 25.48), the UVA/RF transepithelial group (369.86 ± 23.43), and the control group (365.14 ± 28.74). Still, there was no significant differences in both biomechanical CCT (p=0.990). Transglutaminase-induced CXL group had the highest mean of keratocyte cell density (43.26 ± 10.65) compared to UVA/RF epithelial-off (29.99 ± 4.79), UVA/RF transepithelial group (42.03 ± 6.55), and control group (34.36 ± 6.76). There was a significant difference between the group, with a p-value of 0.008.&#x0D; Conclusion : Transglutaminase shown that it produces favorable results for CCT and keratocyte density after CXL, which are two factors contributing to corneal rigidity. The outcomes are equivalent to riboflavin used as a conventional element in CXL.

Effects of synthesis temperature on structures and properties of epoxidized soybean oil oligomers and starch‐based bioplastics

AbstractThe work investigated the synthesis of the oligomers with citric acid (CA) and epoxidized soybean oils (ESO) at various temperatures and the effects of the oligomers on the structures and properties of starch‐based bioplastics. CA was bonded effectively onto ESO via ring‐opening polymerization at 90°C as confirmed by the results of Fourier‐transform infrared spectroscopy, thermogravimetric analysis, and carboxylic group contents of CA‐ESO oligomers (CESO). The oligomers exhibited higher thermal stability than ESO. Regarding starch‐based bioplastics, CESO disrupted the hydrogen bonding interaction within starch molecules and formed the esterification reaction with starch. The bioplastics containing CESO exhibited remarkably higher structural homogeneity and opacity as the synthesis temperatures of CESO increased. However, the thermal properties of the bioplastics with various CESO reduced, which might be due to the decomposition of starch by CESO. The films containing CESO also exhibited lower tensile strength than the film with ESO, which might be related to the decomposition, crosslinking, and plasticization effects of CESO on starch. The bioplastics with CESO exhibited lower degradation due to a more intense interaction of CESO and starch. The study demonstrated the potential of CA as an interfacial linker of starch/ESO‐based bioplastics by adjusting the synthetic temperatures of CESO.

Effect of High Humidity Exposure to Wheat Starch Based High Conducting Flexible Polymer‐in‐Salt‐Electrolyte

AbstractPolymer‐in‐salt‐electrolytes (PISEs) are an important class of electrolytes as they carry the promise of faster and single ion transport. Unfortunately, due to unavailability of a suitable polymer host PISE has still not reached to commercial level. In the present work, using a novel synthesis protocol developed by the group, glutaraldehyde crosslinked wheat starch has been successfully modified with sodium iodide (NaI) to synthesize a flexible PISE membrane with desired electrochemical properties. Present paper reports the effect of crosslinker and exposure to high humidity ambience on electrochemical and morphological properties. It has been established that on exposure to higher humidity atmosphere starch‐based PISEs stabilize at lower resistance value, but with higher ion relaxation time, which indicates that effect of high humidity treatment is more on salt dissociation instead of assisting the ion transport. The studied materials have conductivity ≈0.01 S cm−1 range with ESW &gt;2.5 V, ensuring its usability in electrochemical devices. The developed synthesis protocol does not require any complicated synthesis route and/or sophisticated instrument hence the overall process is economical also, adding up to its potentiality for energy device fabrication.

Ultrastable, Superrobust, and Recyclable Supramolecular Polymer Networks

AbstractSupramolecular polymer networks (SPNs), crosslinked by noncovalent bonds, have emerged as reorganizable and recyclable polymeric materials with unique functionality. However, poor stability is an imperative challenge faced by SPNs, because SPNs are susceptible to heat, water, and/or solvents due to the dynamic and reversible nature of noncovalent bonds. Herein, the design of a noncovalent cooperative network (NCoN) to simultaneously stabilize and reinforce SPNs is reported, resulting in an ultrastable, superrobust, and recyclable SPN. The NCoN is constructed by multiplying the H‐bonding sites and tuning the conformation/geometry of the H‐bonding segment to optimize the multivalence cooperativity of H‐bonds. The rationally designed H‐bonding segment with high conformational compliance favors the formation of tightly packed H‐bond arrays comprising higher‐density and stronger H‐bonds. Consequently, the H‐bonded crosslinks in the NCoN display a covalent crosslinking effect but retain on‐demand dynamics and reversibility. The resultant ultrastable SPN not only displays remarkable resistance to heat up to 120 °C, water soaking, and a broad spectrum of solvents, but also possesses a superhigh true stress at break (1.1 GPa) and an ultrahigh toughness (406 MJ m−3). Despite the covalent‐network‐like stability, the SPN is recyclable through activating its reversibility in a high‐polarity solvent heated to a threshold temperature.

Ultrastable, Superrobust, and Recyclable Supramolecular Polymer Networks.

Supramolecular polymer networks (SPNs), crosslinked by noncovalent bonds, have emerged as reorganizable and recyclable polymeric materials with unique functionality. However, poor stability is an imperative challenge faced by SPNs, because SPNs are susceptible to heat, water, and/or solvents due to the dynamic and reversible nature of noncovalent bonds. Herein, the design of a noncovalent cooperative network (NCoN) to simultaneously stabilize and reinforce SPNs is reported, resulting in an ultrastable, superrobust, and recyclable SPN. The NCoN is constructed by multiplying the H-bonding sites and tuning the conformation/geometry of the H-bonding segment to optimize the multivalence cooperativity of H-bonds. The rationally designed H-bonding segment with high conformational compliance favors the formation of tightly packed H-bond arrays comprising higher-density and stronger H-bonds. Consequently, the H-bonded crosslinks in the NCoN display a covalent crosslinking effect but retain on-demand dynamics and reversibility. The resultant ultrastable SPN not only displays remarkable resistance to heat up to 120 °C, water soaking, and a broad spectrum of solvents, but also possesses a superhigh true stress at break (1.1 GPa) and an ultrahigh toughness (406 MJ m-3 ). Despite the covalent-network-like stability, the SPN is recyclable through activating its reversibility in a high-polarity solvent heated to a threshold temperature.

Investigation of the effects of cellulose nanofiber on the properties of poly(vinyl alcohol) crosslinked by 2,5-furandicarboxylic acid

Bio-based and biodegradable materials have received special interests in recent years as a replacement for petroleum-based plastics. Poly(vinyl alcohol) (PVA), cellulose nanofiber (CNF), and 2,5-furandicarboxylic acid (FDCA) are typical examples among these environmentally friendly molecules. In this study, we investigated the synergistic effects of CNF reinforcement and crosslinking with FDCA on the properties of PVA. The composite films were prepared via a straightforward mechanical-dispersion method, wherein CNF was incorporated into a PVA solution and subsequently crosslinked with FDCA. Comprehensive characterizations, including Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-IR), X-ray diffraction (XRD), Thermal Gravimetric Analysis/Differential Thermal Gravimetric Analysis (TGA/DTGA), Differential Scanning Calorimetry (DSC), tensile testing, and morphological studies, were performed to assess the impact of these modifications. Our findings revealed significant enhancements in the mechanical and thermal properties of the composites. Notably, the tensile strength of the PVA-c-FDCA/CNF composite with 2% CNF reached 37.08 MPa, representing a twofold increase compared to both crosslinked PVA (16.84 MPa) and unmodified PVA (14.57 MPa). TGA/DTGA analysis demonstrated improved thermal stability, with the degradation temperature reaching 371°C, compared to the 298°C observed for PVA. DSC and XRD results indicated a reduction in PVA crystallinity after crosslinking and blending with CNF. Scanning electron microscopy (SEM) images showed good compatibility between PVA and CNF. This study underscores the potential of CNF reinforcement and FDCA crosslinking as a viable strategy to enhance the mechanical properties of PVA-based materials.

Reduction of starch granule surface lipids alters the physicochemical properties of crosslinked maize starch

Normal and waxy maize starches with and without removal of starch granule surface lipids (SGSLs) were crosslinked by POCl3 (0.01 %, 0.1 % and 1 %). Crosslinked starches showed lower swelling power and solubility, but higher pasting viscosity, pseudoplasticity, thixotropy, storage modulus and loss modulus. Crosslinking increased the double helical structure but decreased the crystallinity for waxy maize starch. The phosphorus content of crosslinked waxy maize starches after SGSLs removal increased, indicating SGSLs removal promoted crosslinking. SGSLs removal increased G' and G" for crosslinked waxy maize starches. SGSLs removal increased SP and solubility and decreased pasting and rheological parameters of starches. With increased POCl3 dosage, the effect of SGSLs removal on starch properties was gradually suppressed by crosslinking. Waxy and normal maize starches showed significantly different changes with crosslinking and SGSLs removal, and the presence of amylose seemed to impede the effect of crosslinking and SGSLs removal. The removal of SGSLs could extend the application of crosslinked starch in frozen foods, drinks, and canned foods as thickener and stabilizer, due to its better hydrophilicity and viscous liquid-like rheological properties. The study will assist carbohydrate chemists and food processors in developing new food products.

Water Reduction of Biodegradable Plastic From Bagasse By‐Product With Synergistic Effect of Graphene Oxide Reinforcement and Citric Acid Crosslinking

In today’s world, plastics are vital as they are used in a wide range of applications although packaging is the most prevalent. Most of the plastics that are used for packaging applications are derived from petrochemicals. These plastics meet most of the requirements for good packing applications. However, they are not completely biodegradable. This consequently pollutes the environment. As a result, biodegradable plastics have emerged as an alternative to conventional plastics. Cellulose is one of the potential materials that are used for making biodegradable plastics. However, making plastic from cellulose causes deforestation. In this work, plastic was produced from cellulose bagasse, which is an industrial waste. Since bagasse is an industrial by‐product, it causes neither deforestation nor scarcity of food. However, the plastic made from bagasse showed high water absorption and low tensile strength. To overcome this problem, the plastic, which is made from bagasse, was reinforced with various concentrations of graphene oxide (GO) and crosslinked with various concentrations of citric acid (CA) at different crosslinking temperatures and crosslinking times. The water absorption and biodegradability of the films were studied. Furthermore, the synergistic effect of crosslinking and reinforcement was used to improve the interfacial bonding between the two. The water absorption of pure cellulose, cellulose crosslinked with 10% CA, cellulose reinforced with 15% GO reinforcement, and synergy of 10% CA crosslinking and 15% GO reinforcement at crosslinking temperature of 130°C and crosslinking time of 25 min was found to be 99.02%, 56.4%, 44.275%, and 36.78%, respectively. The biodegradability at the optimal values of crosslinker concentration, crosslinking time, and crosslinking temperature of pure cellulose of bagasse, 10% CA crosslinked bagasse, and 10% CA crosslinked bagasse with 15% GO reinforcement in 30 days were found to be 94.0397%, 56.91%, and 40.81%, respectively. The result of the study shows that water‐resistant biodegradable plastic can be produced with the synergistic effect of crosslinking and reinforcement.

Highly elastic relaxor ferroelectric via peroxide crosslinking.

Relaxor ferroelectrics are well-known for their high dielectric constants, low dielectric losses, and excellent electromechanical properties, making them valuable for various electronic devices. Despite recent efforts to enhance the durability of ferroelectrics through chemical cross-linking, achieving elasticity in relaxor ferroelectric materials remains a significant challenge. These materials inherently possess traits such as low crystallinity and small crystal size, while chemical crosslinking tends to diminish polymer crystallinity considerably. Thus, a key obstacle to making relaxor ferroelectric polymers elastic lies in safeguarding their crystalline regions from the effects of slight crosslinking. To tackle this issue, we selected P(VDF-CTFE-DB) with highly reactive C[double bond, length as m-dash]C double bonds as crosslinking sites, reducing the amount of cross-linking agents added and thereby lessening their impact on crystallinity. Through peroxide crosslinking, we transformed linear P(VDF-CTFE-DB) into a network structure, successfully producing a resilient relaxor ferroelectric material with maintained polarization intensity for ferroelectricity. Notably, this elastic relaxor ferroelectric was synthesized at relatively low temperatures, exhibiting a remarkable dielectric constant, superior resilience, fatigue resistance, and a stable ferroelectric response even under strains of up to 80%. Our approach paves the way for developing low-cost, high-dielectric-constant elastomers suitable for wearable electronics and related applications.

Effect of Corneal Collagen Crosslinking with Riboflavin in Patients of Progressive Keratoconus: A Prospective Cohort Study

Introduction: Keratoconus is a non inflammatory disease characterised by progressive corneal thinning that results in a cone-like ectasia, irregular astigmatism, and decreased vision. Advanced disease can result in corneal scarring and blindness, necessitating penetrating keratoplasty. The only treatment believed to have the ability to stop or decrease the progression of keratoconus is Collagen Cross-Linking (CXL). Aim: To evaluate the efficacy of corneal collagen cross-linking with riboflavin (C3R) in patients with keratoconus by studying the outcomes in terms of Uncorrected Visual Acuity (UCVA), Best Corrected Visual Acuity (BCVA), manifest refraction, and corneal topography. Materials and Methods: A hospital-based prospective cohort study was conducted at the Regional Institute of Ophthalmology, Government Medical College, Thiruvananthapuram, Kerala, India from June 2017 to June 2018. Fifteen eyes of 12 patients who underwent corneal collagen cross-linking for progressive keratoconus were included. Routine ophthalmological examinations was done for all patients. Patients under the age of 35 years with progressive keratoconus, an average K value not exceeding 60 D, and who had not undergone any other surgical modalities of treatment were included in the study. Patients with scarred cornea or hydrops, active ocular infection, or pachymetry &lt;400 µm were excluded. Detailed informed consent was obtained from all patients before surgery. Preoperative UCVA, BCVA cylinder, Spherical Equivalent (SE), and topography values were obtained. All patients were followed-up at three and six months postoperative period to look for changes in UCVA, BCVA, manifest refraction, and corneal topography. Data were expressed as the mean±Standard Deviation (SD) pre- and postoperatively and analysed statistically using the paired t-test, with p&lt;0.05 considered statistically significant. Analysis was conducted using Statistical Package for Social Sciences (SPSS) version 16.0. Results: On follow-up at six months post-treatment, UCVA (log MAR) improved from 0.87±0.40 to 0.65±0.35 (p-value=0.001), and BCVA (log MAR) changed from 0.37±0.21 to 0.17±0.22 (p-value=0.001). K max decreased from 54.90±6.05 to 52.67±5.02 (p-value=0.001), and K min decreased from 48.14±4.24 to 45.93±4.07 (p-value=0.001). Astigmatism and SE also showed statistically significant improvement post-procedure (p-value 0.001 and 0.002, respectively). Astigmatism reduced from -3.50±1.58 to -2.90±1.37. SE reduced from -4.93±3.92 to -4.28±3.48. No significant complications were noted in any of the patients. Conclusion: The CXL is an effective procedure for stabilising the progression of keratoconus, thus reducing the burden of preventable blindness and the need for keratoplasty.