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1.
Chem Eng J ; 464: 142588, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36992868

RESUMO

The worldwide spread of COVID-19 has put a higher requirement for personal medical protective clothing, developing protective clothing with sustained antibacterial and antiviral performance is the priority for safe and sustaining application. For this purpose, we develop a novel cellulose based material with sustained antibacterial and antiviral properties. In the proposed method, the chitosan oligosaccharide (COS) was subjected to a guanylation reaction with dicyandiamide in the presence of Scandium (III) triflate; because of the relatively lower molecular weight and water solubility of the COS, GCOS (guanylated chitosan oligosaccharide) with high substitution degree (DS) could be successfully synthetized without acid application. In this instance, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the GCOS were only 1/8 and 1/4 of that of COS. The introduction of GCOS onto the fiber endowed the fiber with extremely high antibacterial and antiviral performance, showing 100% bacteriostatic rate against Staphylococcus aureus and Escherichia coli and 99.48% virus load reduction of bacteriophage MS2. More importantly, the GCOS modified cellulosic fibers (GCOS-CFs) exhibit excellent sustained antibacterial and antiviral properties; namely, 30 washing cycles had negligible effect on the bacteriostatic rate (100%) and inhibition rate of bacteriophage MS2 (99.0%). Moreover, the paper prepared from the GCOS-CFs still exhibited prominent antibacterial and antiviral activity; inferring that the sheeting forming, press, and drying process have almost no effect on the antibacterial and antiviral performances. The insensitive of antibacterial and antiviral activity to water washing (spunlace) and heat (drying) make the GCOS-CFs a potential material applicable in the spunlaced non-woven fabric production.

2.
Nano Lett ; 22(9): 3516-3524, 2022 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-35363493

RESUMO

Thermal insulating fibers can effectively regulate the human body temperature and decrease indoor energy consumption. However, designing super thermal insulating fibers integrating a sponge and aerogel structure based on biomass resources is still a challenge. Herein, a flow-assisted dynamic dual-cross-linking strategy is developed to realize the steady fabrication of regenerated all-cellulose graded sponge-aerogel fibers (CGFs) in a microfluidic chip. The chemically cross-linked cellulose solution is used as the core flow, which is passed through two sheath flow channels, containing either a diffusion solvent or a physical cross-linking solvent, resulting in CGFs with a porous sponge outer layer and a dense aerogel inner layer. By regulating and simulating the flow process in the microfluidic chip, CGFs with adjustable sponge thicknesses, excellent toughness (26.20 MJ m-3), and ultralow thermal conductivity (0.023 W m-1 K-1) are fabricated. This work provides a new method for fabricating graded biomass fibers and inspires attractive applications for thermal insulation in textiles.


Assuntos
Celulose , Nanoestruturas , Celulose/química , Humanos , Porosidade , Solventes , Condutividade Térmica
3.
Molecules ; 28(4)2023 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-36838941

RESUMO

In this work, bio-based hydrogel composites of xanthan gum and cellulose fibers were developed to be used both as soil conditioners and topsoil covers, to promote plant growth and forest protection. The rheological, morphological, and water absorption properties of produced hydrogels were comprehensively investigated, together with the analysis of the effect of hydrogel addition to the soil. Specifically, the moisture absorption capability of these hydrogels was above 1000%, even after multiple dewatering/rehydration cycles. Moreover, the soil treated with 1.8 wt% of these materials increased the water absorption capacity by approximately 60% and reduced the water evaporation rate, due to the formation of a physical network between the soil, xanthan gum and cellulose fibers. Practical experiments on the growth of herbaceous and tomato plants were also performed, showing that the addition of less than 2 wt% of hydrogels into the soil resulted in higher growth rate values than untreated soil. Furthermore, it has been demonstrated that the use of the produced topsoil covers helped promote plant growth. The exceptional water-regulating properties of the investigated materials could allow for the development of a simple, inexpensive and scalable technology to be extensively applied in forestry and/or agricultural applications, to improve plant resilience and face the challenges related to climate change.


Assuntos
Agricultura Florestal , Água , Polissacarídeos Bacterianos , Solo , Celulose , Hidrogéis
4.
Fish Shellfish Immunol ; 120: 421-428, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34896292

RESUMO

The use of probiotics, prebiotics and dietary fiber has become a common practice in shrimp aquaculture as alternatives to antibiotic treatment. However, not much is known about the metabolic mechanisms underlying the effects of probiotics and immunostimulant used in shrimp aquaculture. In this study, a gas chromatography-mass spectrometry (GC-MS) based metabolomics approach was used to characterize metabolite profiles of haemolymph and gills of whiteleg shrimp (Penaeus vannamei) exposed to four treatments (cellulose fiber, probiotics with Vibrio alginolyticus, a combination of cellulose fiber and V. alginolyticus and a control treatment). The cellulose fiber was administrated as a feed additive (100 mg⋅Kg-1 feed), while the probiotics was applied in the water (105 UFC⋅mL-1 culture water). The results showed significant differences in haemolymph metabolite profiles of immune stimulated treatments compared to the control and among treatments. The combination of cellulose fiber and probiotics resulted in greater differences in metabolic profiles, suggesting a better immune stimulation with this approach. The changes in haemolymph metabolome of treated shrimp reflected several biochemical pathway modifications, including changes in amino acid and fatty acid metabolism, disturbances in energy metabolism and antimicrobial activity and stress responses. For gill tissues, significant differences were only found in lactic acid between the probiotic group and the control. Among the altered metabolites, the increases of itaconic acid in haemolymph, and lactic acid in both haemolymph and gill tissues of immune-stimulated suggest the potential use of these metabolites as biomarkers for health assessment in aquaculture.


Assuntos
Adjuvantes Imunológicos/farmacologia , Metabolômica , Penaeidae , Probióticos , Animais , Aquicultura , Celulose , Dieta/veterinária , Ácido Láctico , Penaeidae/imunologia
5.
Molecules ; 27(8)2022 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-35458593

RESUMO

The growing concern about environmental pollution has generated an increased demand for biobased and biodegradable materials intended particularly for the packaging sector. Thus, this study focuses on the effect of two different cellulosic reinforcements and plasticized poly(3-hydroxybutyrate) (PHB) on the properties of poly(lactic acid) (PLA). The cellulose fibers containing lignin (CFw) were isolated from wood waste by mechanical treatment, while the ones without lignin (CF) were obtained from pure cellulose by acid hydrolysis. The biocomposites were prepared by means of a melt compounding-masterbatch technique for the better dispersion of additives. The effect of the presence or absence of lignin and of the size of the cellulosic fibers on the properties of PLA and PLA/PHB was emphasized by using in situ X-ray diffraction, polarized optical microscopy, atomic force microscopy, and mechanical and thermal analyses. An improvement of the mechanical properties of PLA and PLA/PHB was achieved in the presence of CF fibers due to their smaller size, while CFw fibers promoted an increased thermal stability of PLA/PHB, owing to the presence of lignin. The overall thermal and mechanical results show the great potential of using cheap cellulose fibers from wood waste to obtain PLA/PHB-based materials for packaging applications as an alternative to using fossil based materials. In addition, in situ X-ray diffraction analysis over a large temperature range has proven to be a useful technique to better understand changes in the crystal structure of complex biomaterials.


Assuntos
Celulose , Lignina , Ácido 3-Hidroxibutírico , Celulose/química , Hidroxibutiratos , Lignina/química , Poliésteres/química , Polímeros/química
6.
Molecules ; 26(19)2021 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-34641374

RESUMO

This paper reports the influence of submicron hydrophilic fibers on the hydration and microstructure of Portland cement paste. Submicron fibrillated cellulose (SMC) fibers was prepared by the acid hydrolysis of cotton fibers in H2SO4 solution (55% v/v) for 1.5 h at a temperature of 50 °C. The SMC fibers were added into cement with a dosage of 0.03 wt.%, and the effect of SMC on the hydration and microstructure of cement paste was investigated by calorimeter analysis, XRD, FT-IR, DSC-TG, and SEM. Microcrystalline cellulose (MCC) fibers were used as the contrast admixture with the same dosage in this study. The results show that the addition of SMC fibers can accelerate the cement hydration rate during the first 20 h of the hydration process and improve the hydration process of cement paste in later stages. These results are because the scale of SMC fibers more closely matches the size of the C-S-H gel compared to MCC fibers, given that the primary role of the SMC is to provide potential heterogeneous nucleation sites for the hydration products, which is conducive to an accelerated and continuous hydration reaction. Furthermore, the induction and bridging effects of the SMC fibers make the cement paste microstructure more homogeneous and compact.

7.
Molecules ; 26(18)2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34577065

RESUMO

Green composites, composed of bio-based matrices and natural fibers, are a sustainable alternative for composites based on conventional thermoplastics and glass fibers. In this work, micronized bleached Eucalyptus kraft pulp (BEKP) fibers were used as reinforcement in biopolymeric matrices, namely poly(lactic acid) (PLA) and poly(hydroxybutyrate) (PHB). The influence of the load and aspect ratio of the mechanically treated microfibers on the morphology, water uptake, melt flowability, and mechanical and thermal properties of the green composites were investigated. Increasing fiber loads raised the tensile and flexural moduli as well as the tensile strength of the composites, while decreasing their elongation at the break and melt flow rate. The reduced aspect ratio of the micronized fibers (in the range from 11.0 to 28.9) improved their embedment in the matrices, particularly for PHB, leading to superior mechanical performance and lower water uptake when compared with the composites with non-micronized pulp fibers. The overall results show that micronization is a simple and sustainable alternative for conventional chemical treatments in the manufacturing of entirely bio-based composites.


Assuntos
Celulose/análogos & derivados , Nanocompostos/química , Eucalyptus/química , Hidroxibutiratos/química , Poliésteres/química , Resistência à Tração , Molhabilidade
8.
Int J Mol Sci ; 21(15)2020 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-32751335

RESUMO

In this study, hexagonal boron nitride nanosheets enriched with hydroxyl groups (h-BN-OH) were successfully grafted on the surface of cellulose fibers after the simple and effective exfoliation and oxidation of bulk h-BN. OH groups of h-BN-OH and the ones presented on the surface of cellulose fibers interacted via hydrogen bonding. Both spectroscopic (FT-IR, XRD) and microscopic (TEM, SEM, and atomic force microscopy (AFM)) methods results proved the successful functionalization of the cellulose fibers with the nanomaterial. Modified cellulose fibers were used to prepare paper sheets samples with different concentrations of the nanomaterial (1 wt %, 2 wt %, and 3 wt %). All the samples were tested for the antibacterial properties via the colony forming unit method and exhibited good performance against both Gram-negative (E. coli) and Gram-positive (S. epidermidis) model bacteria. Additionally, the influence of the volume of working bacterial suspension on the antibacterial efficiency of the obtained materials was examined. The results showed significantly better antibacterial performance when the volume of bacterial suspension was reduced. Mechanical properties of the paper samples with and without nanofiller were also characterized. Tensile strength, tearing strength, and bursting strength of the paper samples containing only 2 wt % of the nanofiller were improved by 60%, 61%, and 118% in comparison to the control paper samples, respectively. Furthermore, the nanofiller improved the thermal properties of the composite paper-the heat release rate decreased by up to 11.6%. Therefore, the composite paper can be further explored in a wide range of antibacterial materials, such as packaging or paper coatings.


Assuntos
Antibacterianos/farmacologia , Compostos de Boro/farmacologia , Celulose/farmacologia , Nanocompostos/toxicidade , Antibacterianos/química , Compostos de Boro/química , Celulose/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Humanos , Ligação de Hidrogênio , Teste de Materiais , Testes de Sensibilidade Microbiana , Nanocompostos/química , Nanocompostos/ultraestrutura , Oxirredução , Papel , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Resistência à Tração
9.
Molecules ; 25(6)2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-32178229

RESUMO

A recently developed cellulose hybrid chemical treatment consists of two steps: solvent exchange (with ethanol or hexane) and chemical grafting of maleic anhydride (MA) on the surface of fibers. It induces a significant decrease in cellulose moisture content and causes some changes in the thermal resistance of analyzed blend samples, as well as surface properties. The thermal characteristics of ethylene-norbornene copolymer (TOPAS) blends filled with hybrid chemically modified cellulose fibers (UFC100) have been widely described on the basis of differential scanning calorimetry and thermogravimetric analysis. Higher thermal stability is observed for the materials filled with the fibers which were dried before any of the treatments carried out. Dried cellulose filled samples start to degrade at approximately 330 °C while undried UFC100 specimens begin to degrade around 320 °C. Interestingly, the most elevated thermal resistance was detected for samples filled with cellulose altered only with solvents (both ethanol and hexane). In order to support the supposed thermal resistance trends of prepared blend materials, apparent activation energies assigned to cellulose degradation (EA1) and polymer matrix decomposition (EA2) have been calculated and presented in the article. It may be evidenced that apparent activation energies assigned to the first decomposition step are higher in case of the systems filled with UFC100 dried prior to the modification process. Moreover, the results have been enriched using surface free energy analysis of the polymer blends. The surface free energy polar part (Ep) raises considering samples filled with not dried UFC100. On the other hand, when cellulose fibers are dried prior to the modification process, then the blend sample's dispersive part of surface free energy is increased with respect to that containing unmodified fiber. As polymer blend Ep exhibits higher values reflecting enhanced material degradation potential, the cellulose fibers employment leads to more eco-friendly production and responsible waste management. This is in accordance with the rules of sustainable development.


Assuntos
Celulose/química , Elastômeros/química , Nanocompostos/química , Poliésteres/química , Solventes/química , Propriedades de Superfície , Temperatura , Resistência à Tração
10.
Molecules ; 25(17)2020 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-32872500

RESUMO

For the preparation of activated carbon papers (APCs) as supercapacitor electrodes, impurity substances were removed from rice husks, before carbonization and various activation temperature treatments, to optimize electro chemical efficiency. The porosities and electrochemical performances of the ACPs depended strongly on activation temperature: The specific surface area increased from 202.92 (500 °C) to 2158.48 m2 g-1 (1100 °C). XRD and Raman analyses revealed that ACP graphitization also increased with the activation temperature. For activation at 1100 °C, the maximum specific capacitance was 255 F g-1, and over 92% of its capacitance was retained after 2000 cycles.


Assuntos
Celulose/química , Carvão Vegetal/química , Oryza/química , Papel , Capacitância Elétrica , Eletrodos , Porosidade , Temperatura
11.
Int J Mol Sci ; 20(4)2019 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-30813291

RESUMO

The circular economy policy and the interest for sustainable material are inducing a constant expansion of the bio-composites market. The opportunity of using natural fibers in bio-based and biodegradable polymeric matrices, derived from industrial and/or agricultural waste, represents a stimulating challenge in the replacement of traditional composites based on fossil sources. The coupling of bioplastics with natural fibers in order to lower costs and promote degradability is one of the primary objectives of research, above all in the packaging and agricultural sectors where large amounts of non-recyclable plastics are generated, inducing a serious problem for plastic disposal and potential accumulation in the environment. Among biopolymers, poly(lactic acid) (PLA) is one of the most used compostable, bio-based polymeric matrices, since it exhibits process ability and mechanical properties compatible with a wide range of applications. In this study, two types of cellulosic fibers were processed with PLA in order to obtain bio-composites with different percentages of microfibers (5%, 10%, 20%). The mechanical properties were evaluated (tensile and impact test), and analytical models were applied in order to estimate the adhesion between matrix and fibers and to predict the material's stiffness. Understanding these properties is of particular importance in order to be able to tune and project the final characteristics of bio-composites.


Assuntos
Materiais Biocompatíveis/química , Celulose/química , Teste de Materiais/métodos , Poliésteres/química , Celulose/ultraestrutura , Módulo de Elasticidade , Termogravimetria
12.
Int J Biol Macromol ; 273(Pt 2): 133158, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38878937

RESUMO

Enhancing the flame retardancy and durability of cellulose fibers, particularly environmentally friendly regenerated cellulose fibers types like Lyocell fibers, is essential for advancing their broader application. This study introduced a novel approach to address this challenge. Cationic-modified Lyocell fibers (Lyocell@CAT) were prepared by introducing quaternary ammonium structures into the molecular chain of Lyocell fibers. Simultaneously, a flame retardant, APA, containing -COO-NH4+ and -P=O(O-NH4+)2 groups was synthesized. APA was then covalently bonded to Lyocell@CAT to prepare Lyocell@CAT@APA. Even after undergoing 30 laundering cycles (LCs), Lyocell@CAT@APA maintained a LOI value of 37.2 %, exhibiting outstanding flame retardant durability. The quaternary ammonium structure within Lyocell@CAT@APA formed asymmetric ionic bonds with the phosphate and carboxylate groups in APA, effectively shielding the binding of Na+ ions with phosphate groups during laundering, thereby enhancing the durability. Additionally, the consumption of Na+ ions by carboxylate groups further prevented their binding to phosphate groups, which contributed to enhance the durability properties. Flame retardant mechanism analysis revealed that both gas and condensed phase synergistically endowed excellent flame retardancy to Lyocell fibers. Overall, this innovative strategy presented a promising prospect for developing bio-safe, durable, and flame retardant cellulose textiles.


Assuntos
Celulose , Retardadores de Chama , Celulose/química , Metais/química , Ácidos Carboxílicos/química , Íons/química , Compostos de Amônio Quaternário/química
13.
Int J Biol Macromol ; 255: 128124, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37981281

RESUMO

In the ionic liquids (ILs) method for processing regenerated cellulose fiber (RCF), which is a high-performance ecologically benign product, metal ion impurities (such as Fe3+ and Cu2+) of cellulose might inevitably remain in the recycled ILs and coagulation bath. The presence of metal ions might negatively impact the properties of the manufactured RCFs and obstruct their applications, which are urgent to be made clear. For this research, the solvent for dissolving wood pulp cellulose (WPC) was 1-ethyl-3-methylimidazolium diethyl phosphate ([Emim]DEP) with various metal ion concentrations. The effect of metal ions in IL on the dissolution of cellulose was investigated by Molecular Dynamics simulations. Rheological analysis and degree of polymerization (DP) analysis were adopted to evaluate the influence on fiber spinnability of different spinning solution metal ion concentrations and various dissolving times. Further, the morphology and mechanical performances of the RCFs variation regulation were also thoroughly researched. The findings showed that the presence of metal ions in the spinning solution affected the DP, crystallinity, and orientation factor of RCFs, which will influence their stress more sensitively than the strain. These findings can serve as a practical guide for the commercial manufacture of emerging fiber.


Assuntos
Celulose , Líquidos Iônicos , Solventes/química , Celulose/química , Líquidos Iônicos/química , Íons
14.
Int J Biol Macromol ; 274(Pt 2): 133550, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39030156

RESUMO

The escalating global population has led to a surge in waste textiles, posing a significant challenge in landfill management worldwide. In this work, ionic liquid 1-butyl-3-methylimidazole acetate ([Bmim]OAc) and DMF (N, n-dimethylformamide) were used as solvents to dissolve waste denim fabric, then vanadium dioxide (VO2) nanoparticles were introduced into the spinning solution, and cellulose fibers were regenerated by dry-wet spinning process, to promote the recycling of waste cotton fabric. Finally, regenerated cellulose fibers with high added value were prepared by dry-wet spinning. Through this innovative strategy, on the one hand, because VO2 can form a large number of hydrogen bonds between the regenerated cellulose molecules, and realize the cross-networking structure of the molecular chains inside the fiber, the mechanical properties of the regenerated cellulose fibers are enhanced. On the other hand, due to the thermal phase transformation characteristics of VO2, it also endows the regenerated cellulose fiber unique intelligent temperature control function. Compared with the pristine regenerated fiber, the tensile stress of the regenerated fiber after adding VO2 nanoparticles (F-VO2) increased by 25.6 %, reaching 158.68 MPa. In addition, the F-VO2 fibric provides excellent intelligent temperature control, reducing temperatures by up to 6.7 °C.


Assuntos
Celulose , Temperatura , Celulose/química , Resistência à Tração , Fenômenos Mecânicos , Nanopartículas/química
15.
Int J Biol Macromol ; 277(Pt 1): 133911, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39059529

RESUMO

Recycling of waste cotton fabrics (WCFs) is a desirable solution to address the problems brought up by fast fashion, but it remains challenging due to inherent limitations in preparing stable and spinnable dopes by dissolving high molecular weight cellulose efficiently and cost effectively. Herein, we show that despite the prevailing concerns of cellulose degradation via glycosidic hydrolysis when dissolved in acids, fast and non-destructive direct dissolution of WCFs in aqueous phosphoric acid (a.q. PA) could be realized using a cyclic freeze-thawing procedure, which combined with subsequent adjustment of degree of polymerization (DP) and degassing yielded stable and spinnable dopes. Regenerated cellulose fibers (RCFs) with favorable tensile strength (414.2 ± 14.3 MPa) and flexibility (15.4 ± 1.5 %) could be obtained by carefully adjusting the coagulation conditions to induce oriented and compact packing of the cellulose chains. The method was shown to be conveniently extended to dissolve reactively dyed WCFs, showing great potential as a cheap and green alternative to heavily explored ionic liquids (ILs) and N-methylmorpholine-N-oxide (NMMO)-based systems for textile-to-textile recycling of WCFs.


Assuntos
Celulose , Fibra de Algodão , Ácidos Fosfóricos , Reciclagem , Resistência à Tração , Celulose/química , Ácidos Fosfóricos/química , Têxteis , Congelamento , Hidrólise
16.
Int J Biol Macromol ; 279(Pt 4): 135476, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39260646

RESUMO

Cellulose nanofiber (CNF) has been widely used in MXene film electrodes to improve its mechanical properties and rate capability for supercapacitors. However, all the above enhancements are obtained with inevitably sacrificing the capacitance, because of the non-electrochemically-active characteristic of CNF. Herein, to address this issue, lignin-containing cellulose fibers (LCNF) is innovatively used to substitute CNF. Specifically, LCNF play a role as a bridge to significantly reinforce mechanical strength of LCNF/MXene film electrode (LM) by binding the adjacent MXene nanosheets, reaching a tensile strength of 34.2 MPa. Lignin in LCNF contributes to pseudocapacitance through the reversible conversion of its quinone/hydro-quinone (Q/QH2), thus yielding an excellent capacitance of 364.4 F g-1 at 1 A g-1. Meanwhile, LCNF has different diameters in which microfibers form a loose structure for LM, nanofibers enlarge d-spacing between adjacent MXene nanosheets, and fibers self-crosslinking creates abundant pores, thus constructing graded channels to achieve an outstanding rate capability of 87 % at 15 A g-1. The fabricated supercapacitor demonstrates a large energy density of 1.8 Wh g-1 at 71.3 W g-1. This work provides a promising approach to decouple the trade-off between electrochemical performance and mechanical properties of MXene film electrodes caused by using CNF, thus obtaining high-performance supercapacitors.

17.
Polymers (Basel) ; 16(16)2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39204530

RESUMO

Polyoxymethylene (POM), an engineering polymer commonly used in tribological applications, is often reinforced with fossil-based fibers such as carbon and/or glass fibers to improve its properties. To find more sustainable solutions, in this study, the tribological performance of POM/short cellulose fiber composites at different sliding conditions is investigated. An improvement in the wear coefficient of roughly 69% is observed at the harshest conditions of 5 MPa and 1 m · s-1 with only 10 wt.% cellulose fibers. The friction behavior is furthermore stabilized through fiber addition, as the unfilled polymer did not show a steady state. No signs of thermo-oxidative degradation are found after tribological testing. This study presents promising results for sustainable wear-resistant polymer materials in tribological applications.

18.
Int J Biol Macromol ; 277(Pt 3): 134169, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39097057

RESUMO

The uncontrolled administration of the cisplatin drug (CPTN) resulted in numerous drawbacks. Therefore, effective, affordable, and biocompatible delivery systems were suggested to regulate the loading, release, and therapeutic effect of CPTN. Zinc phosphate/hydroxyapatite hybrid form (ZP/HP) and core-shell nano-rod morphology, as well as its functionalized derivative with cellulose (CF@ZP/HP), were synthesized by the facile dissolution precipitation method followed by mixing with cellulose fibers, respectively. The developed CF@ZP/HP displayed remarkable enhanced CPTN loading properties (418.2 mg/g) as compared to ZP/HP (259.8 mg/g). The CPTN loading behaviors into CF@ZP/HP follow the Langmuir isotherm properties (R2 > 0.98) in addition to the kinetic activities of the pseudo-first-order model (R2 > 0.96). The steric assessment validates the notable increase in the existing loading receptors after the functionalization of ZP/HP with CF from 57.7 mg/g (ZP/HP) to 90.5 mg/g. The functionalization also impacted the capacity of each existing receptor to be able to ensure 5 CPTN molecules. This, in addition to the loading energies (<40 kJ/mol), donates the loading of CPTN by physical multi-molecular processes and in vertical orientation. The CPTN releasing patterns of CF@ZP/HP exhibit slow and controlled properties (95.7 % after 200 h at pH 7.4 and 100 % after 120 h at pH 5.5), but faster than the properties of ZP/HP. The kinetic modeling of the release activities together with the diffusion exponent (>0.45) reflected the release of CPTN according to both erosion and diffusion mechanisms. The loading of CPTN into both ZP/HP and CF@ZP/HP also resulted in a marked enhancement in the anticancer activity of CPTN against human cervical epithelial malignancies (HeLa) (cell viability = 5.6 % (CPTN), 3.2 % (CPTN loaded ZP/HP), and 1.12 % (CPTN loaded CF@ZP/HP)).


Assuntos
Celulose , Cisplatino , Portadores de Fármacos , Liberação Controlada de Fármacos , Durapatita , Fosfatos , Compostos de Zinco , Celulose/química , Durapatita/química , Durapatita/farmacologia , Cisplatino/farmacologia , Cisplatino/química , Humanos , Portadores de Fármacos/química , Compostos de Zinco/química , Fosfatos/química , Antineoplásicos/farmacologia , Antineoplásicos/química , Cinética , Sobrevivência Celular/efeitos dos fármacos
19.
Int J Biol Macromol ; 264(Pt 1): 130599, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38442834

RESUMO

Cellulosic paper-based electrode materials have attracted increasing attention in the field of flexible supercapacitor. As a conductive polymer, polyaniline exhibits high theoretical pseudocapacitive capacitance and has been applied in paper-based electrode materials along with cellulose fibers. However, the stacking of polyaniline usually leads to poor performance of electrodes. In this study, metal-organic coordination polymers of zirconium-alizarin red S and zirconium-phytic acid are applied to modulate the polyaniline layer to obtain high-performance cellulosic paper-based electrode materials. Zirconium hydroxide is firstly loaded on cellulose fibers while alizarin red S and phytic acid are introduced to regulate the morphology of polyaniline through doping and coordination processes. The results show that the introduction of dual coordination polymers is effective to regulate the morphology of polyaniline on cellulose fibers. The performances of the paper-based electrode materials, including electrical conductivity and electrochemistry, are apparently improved. It provides a promising strategy for the potential development of economical and green electrode materials in the conventional paper-making process.


Assuntos
Compostos de Anilina , Antraquinonas , Celulose , Polímeros , Zircônio , Ácido Fítico , Eletrodos
20.
Int J Biol Macromol ; 272(Pt 2): 132772, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38821299

RESUMO

Bacteria and virus infections have posed a great threat to public health and personnel safety. For realizing rapid sterilization of the bacteria and virus, electrical stimulation sterilization was adopted to endow cellulose fibers with instantaneous antibacterial and antiviral properties. In the proposed strategy, the fiber is fluffed by mechanical refining, and then by means of the hydrogen bond between hydroxyl and aniline, the polyaniline (PANI) directionally grows vertically along the fine fibers via in-situ oxidative polymerization. Benefiting from the conductive polyaniline nanorod arrays on the fiber stem, the paper made from PANI modified refined fibers (PANI/BCF/P) exhibited excellent antibacterial and antiviral activity, the inhibition rates against S. aureus, E. coli, and bacteriophage MS2 can up to 100 %, 100 %, and 99.89 %, respectively when a weak voltage (2.5 V) was applied within 20 min. This study provides a feasible path for plant fiber to achieve efficient antibacterial and antiviral activity with electrical stimulation, which is of great significance for the preparation of electroactive antibacterial and antiviral green health products.


Assuntos
Compostos de Anilina , Antibacterianos , Celulose , Compostos de Anilina/química , Compostos de Anilina/farmacologia , Celulose/química , Celulose/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Estimulação Elétrica , Esterilização/métodos , Antivirais/química , Antivirais/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Levivirus/efeitos dos fármacos
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