The maximum absorption spectrum curves of Acid Red GR and Reactive Brilliant Red X-3B were measured by an ultraviolet spectrophotometer, and the absorption of the dye solution before and after. The FTIR spectra of the maize straw stained with Acid Red GR before and after ultraviolet irradiation are shown in Figure 5. The FTIR spectra of the corn straw stained with Reactive Brilliant Red X-3B before and after ultraviolet radiation are shown in Figure 6.
After the washing treatment, the surface color of the straw dyed with Acid Red GR became markedly lighter and the surface color of the straw dyed with Reactive Brilliant Red X-3B remained bright red, as shown in Figure 9. The chromatismAE* values of the corn straw dyed with Acid Red GR and Reactive Brilliant Red X-3B were 12.09NBS and 17.43NBS, respectively, indicating that the straw dyed with Acid Red GR had good lightfastness.
Patents
The FTIR results showed that Acid Red GR mainly combines with lignin, and the lignin (including aromatic extracts) distributed on the surface of the straw was seriously damaged after UV irradiation when new chromophore groups were formed, resulting in surface discoloration straws. . SEM showed that when 27% H2O2 and 0.1% NaOH were used to bleach corn straw, the removal of silica (SiO2) covering the surface of the straw resulted in obvious damage to the surface of the straw, which contributed to the organic combination of the dye. molecules with the internal components of the straw. After dyeing, the surface of the straw became smoother and the texture was clean, which proved the infiltration or organic combination of the dye.
Water wash fastness analysis showed that the chromatism ΔE* value of corn straw dyed with Reactive Brilliant Red X-3B changed slightly after soaking at 65◦C for 2 hours, and the color did not change visibly with the naked eye, indicating confirmed that the combination of Reactive Brilliant Red X-3B with straw was mainly based on covalent bonding, while Reactive Brilliant Red X-3B mainly acted on cellulose and became a component of straw. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Combined Effects of Color and Elastic Modulus on Antifouling Performance: A Study of Graphene
- Introduction
- Materials and Methods
- Results and Discussions
- Conclusions
We previously reported a new understanding of the effect of modulus of elasticity on antifouling performance, which we referred to as the “harmonic motion effect” [21]; the experimental results of the present study can be explained in terms of this effect. Thus, 0 wt% and 0.16 wt% membranes show poor antifouling performances due to their high Young's modulus. Aπ denotes a detachment force (the force required to separate the fouling organism from the surface) and a low Young's modulus (E) leads to a low detachment force (F√ . Aπ).
The harmonic motion effect sheds new light on the effects of Young's modulus on antifouling behavior. The combined effects of color and Young's modulus determine the antifouling performance of GOSR membranes.
Investigating the Mechanical Properties of ZrO 2 -Impregnated PMMA Nanocomposite for
- Material and Methods 1. Materials
- Results
- Discussion
- Conclusions
The average hardness values for all the samples were determined demonstratively for the materials in the dry state at day 0. A similar behavior was also found for the flexural modulus of the nanocomposites with increasing zirconium oxide content (Table 2). However, a maximum value of the flexural modulus was reached at a zirconia content of 5 wt% (2419 MPa) compared to the control group (1971 MPa), which means an increase of 22.7%.
This could be responsible for the improvement in the flexural properties of the nanocomposites at lower concentrations of zirconia nanoparticles. Chemically modified nanoparticle surfaces with MMA increased the dispersion stability of nanoparticles in the polymer matrix. Lower impact strength in nanocomposites can be related to the presence of voids and clustering of nanoparticles [22,36].
The flexural strength of a high-impact (HI) heat-cured PMMA denture base was significantly increased by the addition of 3 wt% zirconia nanoparticles compared to pure acrylic material (control group). The flexural modulus of a high impact (HI) heat-cured PMMA denture base was significantly increased compared to the control group by addition of zirconia nanoparticles with 1.5 wt. %, 3 wt. %, 5 wt. % and 10 wt. %. For all zirconium dioxide contents, the impact strength of the nanocomposites was significantly lower than that of the control group.
However, at 5 wt% and 3 wt% zirconium oxide content, the proportion of reduction in impact strength was not significantly different from that of the control group. The effect of addition of poly(methyl methacrylate) fibers on some properties of high-strength heat-cured acrylic resin denture base material.J. In vitro evaluation of the flexural properties of All-on-Four provisional fixed denture base resin partially fibre-reinforced.
Cellulose Composites with Graphene for Tissue Engineering Applications
Cellulose Composites with Graphene for Tissue Engineering Applications
According to the FESEM and MTT assay, MG63 cells incubated on all the developed scaffolds showed a normal morphology, but the adhesion and proliferation rates increased on the gelatin-modified one [ 80 ]. GE and GO reinforced BC scaffolds were prepared using an accessible membrane-liquid interface culture (MILIC) method. As expected, BC/GO scaffolds exhibited a better cellular adhesion, spreading, proliferation and osteogenic differentiation compared to neat BC and BC/GE.
The crystallinity of the hybrid BC/GO scaffolds was lower compared to pure BC, while the porosity was higher. For the biological assessment, a neuronal network was constructed by seeding rat embryonic hippocampal neurons (E18) (Figure 5a) on both sides of the synthesized scaffolds and neat BC pellicles for comparison purposes. Human neural stem cells (F3), isolated from embryonic brains, were seeded into the BC and BC/GO-APCLP scaffolds.
Immunofluorescence assays were further used for a better understanding of the cellular proliferation and differentiation processes occurring in the scaffolds. Luciferase activity indicated that the number of F3 cells increased continuously until the 8th day of the study, but mature neuronal markers (MAP2) and synaptic vesicle proteins (synaptophysin) were only present in BC/GO-APCLP scaffolds. Similar to the in vitro tests, most of the cells cultured on BC/GO-APCLP scaffolds showed strong homogeneous staining for MAP2 and synaptophysin.
The nanofibrous scaffolds were immersed in simulated body fluid (SBF) and the biomineralization process was observed by SEM. These results confirm that GO had a positive effect on the ability of CA scaffolds to sustain the development of MCF-7 cells [102]. Schematic description of the method used to prepare nanocomposite films (left); Antibacterial properties, cytotoxicity, biocompatibility and morphology of PLA/CNC-rGO composites (right) [61].
![Figure 2. The fabrication stages of G-C paper and origami inspired cell-laden constructs (left); Rolling and folding of the 3D structures for applications in bone tissue regeneration (right) [58]](https://thumb-ap.123doks.com/thumbv2/1libvncom/9201851.0/44.723.113.619.464.691/figure-fabrication-inspired-constructs-rolling-structures-applications-regeneration.webp)
Conclusions and Future Perspectives
In situ and ex situ modifications of bacterial cellulose for applications in tissue engineering. Mat. Three-dimensional microporous and highly biocompatible bacterial cellulose-gelatin composite scaffolds for tissue engineering applications.RSC Adv. Effect of graphene oxide nanosheets on the physico-mechanical properties of chitosan/bacterial cellulose nanofibrous composites.
Nanographene oxide-reinforced cellulose-derived macroporous frameworks of cross-linked poly(ε-caprolactone) with high internal phase and emulsion. Biomacromolecules. A versatile biomaterial platform enriched with graphene oxide and carbon nanotubes for multiple tissue engineering applications.Int. Combined effect of cellulose nanocrystal and reduced graphene oxide in polylactic acid matrix nanocomposite as framework and its antibacterial activity. Int.
Electrical stimulation-induced osteogenesis of human fat-derived stem cells using a conductive graphene-cellulose scaffold. ExCeL: combination of extrusion printing on cellulose scaffolds with lamination to create in vitro biological models. Biofabrication. Effect of highly dispersed graphene and graphene oxide in 3D nanofiber bacterial cellulose scaffold on cell responses: a comparative study. Mater.
Accelerated biomineralization of cellulose acetate nanofibrous scaffold with graphene oxide for mesenchymal stem cell osteogenesis. Coll. Effect of graphene oxide incorporation into electrospun cellulose acetate scaffolds on breast cancer cell culture. Fibers Polym. Incorporation of graphene oxide into biomimetic nano-microfibrous cellulose scaffolds for improved behavior of breast cancer cells. Cellulose.
Recent Advances in Applications of Cellulose Derivatives-Based Composite Membranes
Applications of Cellulose Derivatives/Hydroxyapatite Composite Membranes 1. Water Purification
In this case, line electron microscopy shows surface changes and the formation of hydroxyapatite crystals in composite membranes, both on the active and on the porous surface of the membrane. On the active surface, a slight decrease in average pore diameter and shape was observed in the case of composite membranes compared to pure cellulose acetate membranes (explained by a weak chemical interaction between the acetate groups of the polymer and the phosphate groups of HA). Incorporation of the functionalized particles into the cellulose acetate matrix improved membrane affinity and led to increased water and salt fluxes in forward and reverse osmosis permeation assays (Figure 3c,d) [56].
Addition of functionalized hydroxyapatite particles in a cellulose acetate carrier improved hydrophilicity and reduced internal concentration polarization, which further. These characteristics are also thought to be involved in the modification of fouling behavior [54]. Morphological studies showed good compatibility between the two organic matrices (CA and HECA) and the hydroxyapatite particles.
Due to the improved dispersion of inorganic particles in the polymer matrix, the double degradation membrane retained its transparency after the addition of HA, while the casting became opaque. The addition of hydroxyapatite nanoparticles broadened the fiber size distribution, but their diameter remained on the nanometer scale. Effect of three key synthesis parameters – ultrasonic dispersion time, hydroxyapatite particle size and powder concentration – on the morphological compositional characteristics of cellulose acetate/hydroxyapatite composite membranes (reproduced with permission from Ref. [91]).
Numerous studies highlighted the important role of calcium in normal skin homeostasis and keratinocyte proliferation and differentiation [93]. Cosmetic appearance of wounds treated with cellulose acetate/gelatin/nano-hydroxyapatite dressings 7 and 14 days after wounding (A) and histograms comparing percentages of wound closure at the end of day 7 and 14 after wounding (B) reproduced with permission from Ref. [50]). The present review focused on the systematic presentation of preparation methods and functional applications of cellulose derivatives/hydroxyapatite composite membranes.
The studies reviewed showed that the addition of hydroxyapatite can impart the desired properties to the surface and structure of the membrane, improving its performance. Dialysis: a review of the mechanisms underlying complications in the treatment of chronic renal failure.Cureus2017,9, e1603.
MDPI
