scholarly journals Preparation and Properties of Chitosan/Graphene Modified Bamboo Fiber Fabrics

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1540 ◽  
Author(s):  
Yan Wu ◽  
Yuqing Bian ◽  
Feng Yang ◽  
Yang Ding ◽  
Kexin Chen

Chitosan (CS) and graphene (Gr) were used to modify bamboo fiber fabrics to develop new bamboo fiber fabrics (CGBFs) with antimicrobial properties. The CGBFs were prepared by chemical crosslinking with CS as binder assistant and Gr as functional finishing agent. The method of firmly attaching the CS/Gr to bamboo fiber fabrics was explored. On the basis of the constant amount of CS, the best impregnation modification scheme was determined by changing the amount of Gr and evaluating the properties of the CS/Gr modified bamboo fiber fabrics. The results showed that the antibacterial rate of CGBFs with 0.3 wt% Gr was more than 99%, and compared with the control sample, the maximum tensile strength of CGBF increased by 1% in the longitudinal direction and 7.8% in the weft direction. The elongation at break increased by 2.2% in longitude and 57.3% in latitude. After 20 times of washing with WOB (without optical brightener) detergent solution, the antimicrobial rate can still be more than 70%. Therefore, these newly CS/Gr modified bamboo fiber fabrics hold great promise for antibacterial application in home decoration and clothing textiles.

2014 ◽  
Vol 28 (3) ◽  
pp. 311-317 ◽  
Author(s):  
Agnieszka Nawrocka

Abstract Silver nanoparticles have antimicrobial properties since they can be regarded as an efficient protector against pathogenic microorganisms. Fourier transform infrared spectroscopy was used to examine conformational changes in the secondary structure of wheat gluten washed out from grain treated with an aqueous solution of silver nanoparticles stabilized by tri-sodium citrate. Silver nanoparticles were used as a protective layer on the grain surface against bacterial and fungal infections (antimicrobial agent). Analysis of the amide I band revealed significant changes in the secondary structure after using silver nanoparticles. An increase in the β-sheet content (from 36.2 to 39.2%) was observed at the expense of the α-helix and β-turn content. To find factors causing these changes, the wheat grains were treated by an aqueous solution of trisodium citrate and water. The results obtained indicate that the changes in the gluten structure were connected mainly with the trisodium citrate action due to presence of a small number of free molecules of the stabilizer in the solution of silver nanoparticles. Additionally, the conformational changes in gluten pointed out that gluten flexibility increased (decrease in the αH/βS ratio from 1.40 for the control sample to 1.26 for the silver nanoparticle-treated samples) as well as the solubility of gluten decreased (decrease in the β-turn content from 13.1 to 11.4%).


2022 ◽  
Vol 12 (2) ◽  
pp. 790
Author(s):  
Mihaela Adriana Tița ◽  
Maria Adelina Constantinescu ◽  
Ovidiu Tița ◽  
Endre Mathe ◽  
Loreta Tamošaitienė ◽  
...  

(1) Background: The demand for healthy and nutritious food is growing worldwide. Fermented dairy products are highly valued by consumers for their health benefits. Kefir is a fermented dairy product that brings many benefits to the consumer due to its antioxidant, anticancer, antidiabetic, antihypertensive and antimicrobial properties. Extracts from various plants in the form of volatile oils have a beneficial efct on consumer health. their antioxidant and antimicrobial activities were demonstrated. (2) Methods: In the present study, the main purpose was to obtain a fermented dairy product with a high nutritional value; therefore, kefir, enriched with three types of volatile oils, namely, volatile mint oil, volatile fennel oil and volatile lavender oil, was made. The kefir samples obtained were sensory and texturally analyzed. The beneficial effect on health must also be studied in terms of the acceptability of these products by consumers from a sensory point of view. A non-numerical method based on several multi-personal approval criteria was used to interpret the results obtained in the sensory analysis. In the textural analysis, the consistency, cohesiveness and firmness of the kefir samples were analyzed. (3) Results: The samples enriched with volatile oils obtained superior results compared to the control sample in both conducted examinations. Kefir samples with volatile oils retained their sensory and textural characteristics for a longer time during storage. (4) Conclusions: The volatile oils added to kefir positively influenced the sensory and textural characteristics of the finished product.


2017 ◽  
Vol 4 (1-4) ◽  
pp. 81-90

As multiresistant and pan-resistant infections continue to emerge, and because the development of novel antimicrobial drugs is a slow process, nanotechnology offers valuable alternatives for fighting resistant bugs, mainly by improving the therapeutic effect of current antimicrobials. Antibiotic resistance is one of the greatest global health threats of the 21st century, but nanotechnology is offering new solutions to the problem. Nanostructured biomaterials, nanoparticles in particular, have unique physicochemical properties such as ultra small and controllable size, large surface area to mass ratio, high reactivity, and functionalizable structure. These properties can be applied to facilitate the administration of antimicrobial drugs, thereby overcoming some of the limitations in traditional antimicrobial therapeutics. Carbon-based nanomaterials such as fullerenes, carbon nanotubes (CNTs) (especially single-walled carbon nanotubes (SWCNTs)) and graphene oxide (GO) nanoparticles) show potent antimicrobial properties. Nanocoating and shuttle systems have shown great promise in vitro and animal models. Noble metals nanostructures, particularly silver, have attracted much attention in the fields of medicine due to their unique properties which are strongly dependent on the size and shape of metal nanomaterials. Recent development of nanocarriers, improved the drug therapy of different diseases, together with the mechanisms of microbial inhibition.


2021 ◽  
Author(s):  
Luca Mazzei ◽  
Lara Massai ◽  
Michele Cianci ◽  
Luigi Messori ◽  
Stefano Ciurli

A few gold compounds were recently found to show antimicrobial properties in vitro, holding great promise for the discovery of new drugs to overcome antibiotic resistance.


2013 ◽  
Vol 411-414 ◽  
pp. 2993-2996
Author(s):  
Yu Pu Deng ◽  
Lin Xue Du ◽  
Xi Hong Li ◽  
Xia Liu ◽  
Hai Jiao Liu

The novel packaging was synthesised by coating polyvinyl chloride (PVC) film with Polyvinylamine/Polyvinyl alcohol (PVAm/PVA) mixture which can effectively inhibit the migration of DOP in this paper. The effect of PVAm/PVA mixture on inhibiting DOP migration was detected via extraction tests. The results showed that the novel packaging significantly reduced the migration rate of DOP compared with the control (PVC film). After 24h extracted by hexane 40% PVAm in mixture being coated on PVC had the lowest migration rate (6.20%) among the samples, while 7.60% is the migration rate of control sample. Tensile properties analysis indicated the elongation at break and tensile strength of samples coating PVAm/PVA higher than control sample. The thermogravimetric analysis demonstrated that the PVAm/PVA mixed solution can deduce thermogravimetric rate. Therefore, coating PVC with PVAm/PVA mixture is an effective approach to suppress the migration of DOP.


Author(s):  
Ilze Grāmatiņa ◽  
Sanita Sazonova ◽  
Zanda Krūma ◽  
Līga Skudra ◽  
Līga Prieciņa

Abstract Oxidation and microbial spoilage have a negative effect on the quality of meat and meat products, causing changes in their sensory and nutritional properties. Herbs contain biologically active compounds, like phenols with antioxidative and antimicrobial properties. Phenols can be used as substitutes for commercial antioxidants to prevent lipid oxidation, thus maintaining the colour and flavour of the product. The aim of the study was to investigate the the potential use of herbal extracts in ethanol/water application for the maintenance of pork meat quality during storage. Four herbs growing in Latvia — nettle (Urtica dioica L.), lovage (Levisticum officinale L.), oregano (Origanum vulgare), and horseradish (Armoracia rusticana L.) were chosen for the study. An optimal ethanol concentration for the extraction of the phenolic compounds was obtained with ethanol 50%/water 50% concentration (v/v). Prepared herbal extracts were added to chilled pork to determine the quality of the pork during storage. Changes in meat quality and its sensory properties for chilled pork without extracts appeared on day 18 of storage. Negative changes in sensory properties of meat samples with nettle extract were observed on day 22 of storage, and with lovage, oregano, and horseradish extracts on day 32. Statistically significant differences (p ≤ 0.05) were observed for microbiological indices between pork samples with herbal extracts and the control sample.


Antibiotics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 340
Author(s):  
Thomas Willems ◽  
Maarten L. De Mol ◽  
Aleksandar De Bruycker ◽  
Sofie L. De Maeseneire ◽  
Wim K. Soetaert

Resistance of pathogenic microorganisms against antimicrobials is a major threat to contemporary human society. It necessitates a perpetual influx of novel antimicrobial compounds. More specifically, Gram− pathogens emerged as the most exigent danger. In our continuing quest to search for novel antimicrobial molecules, alkaloids from marine fungi show great promise. However, current reports of such newly discovered alkaloids are often limited to cytotoxicity studies and, moreover, neglect to discuss the enigma of their biosynthesis. Yet, the latter is often a prerequisite to make them available through sufficiently efficient processes. This review aims to summarize novel alkaloids with promising antimicrobial properties discovered in the past five years and produced by marine fungi. Several discovery strategies are summarized, and knowledge gaps in biochemical production routes are identified. Finally, links between the structure of the newly discovered molecules and their activity are proposed. Since 2015, a total of 35 new antimicrobial alkaloids from marine fungi were identified, of which 22 showed an antibacterial activity against Gram− microorganisms. Eight of them can be classified as narrow-spectrum Gram− antibiotics. Despite this promising ratio of novel alkaloids active against Gram− microorganisms, the number of newly discovered antimicrobial alkaloids is low, due to the narrow spectrum of discovery protocols that are used and the fact that antimicrobial properties of newly discovered alkaloids are barely characterized. Alternatives are proposed in this review. In conclusion, this review summarizes novel findings on antimicrobial alkaloids from marine fungi, shows their potential as promising therapeutic candidates, and hints on how to further improve this potential.


2021 ◽  
Author(s):  
Dezhong Xu ◽  
Yanan Cheng ◽  
Shuai Wu ◽  
Qiuxia Zou ◽  
Ajoy Kanti Mondal ◽  
...  

Abstract In this work, the tunicate cellulose nanocrystal (tCNC) was extracted from tunicate by bleaching and acid hydrolysis. It was used as filler in the preparation of sodium alginate-based enteric capsule. The addition of tCNC with high aspect ratio (65) rendered the enteric capsule excellent physical properties. Compared with the control sample, when the addition of tCNC was 10% (wt), the water contact angle of the capsule was enhanced by 46.0%, the opacity was increased by 356.8%, the maximum tensile stress was increased by 142.6%, the modulus of elasticity was increased by 240.3%, and the elongation at break was increased by 133.8%. In the in vitro degradation experiments, the capsule hardly degraded in the gastric environment (pH 1.2), while in the intestinal environment (pH 6.8), the degradation became slower with the increase of tCNC content, which was consistent with the properties of enteric capsule. This research developed a new direction for the application of tCNC in the pharmaceutical material productions.


2019 ◽  
Vol 956 ◽  
pp. 201-211 ◽  
Author(s):  
Wen Hao Li ◽  
Xiao Yu He ◽  
Shu Wang ◽  
Bing Jie Xu ◽  
Yi Qiang Wu ◽  
...  

In view of the phenomenon that the interfacial adhesion between bamboo fiber(BF)and polylactic acid (PLA) is poor and incompatible. Firstly the BF-g-PLA structure with hydrophobicity is synthesized through grafting lactic acid into bamboo fiber, then plasticizing the composite. Three-element compound plasticizer was prepared by mixing glycerol, tributyl citrate and formamide. The effect of the proportion and addition content of three-element plasticizer on the interfacial compatibility of the composite was investigated. The BF-g-PLA/PLA composites were characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and rotational rheometer (RC) The composites were tested for their bending properties, tensile properties and water resistance properties using national standards. The experimental results show that the best interfacial adhesion between BF-g-PLA and PLA was obtained when the addition content of glycerol, tributyl citrate, formamide was 10%. At the same time, the flexural strength, elastic modulus, tensile strength and elongation at break of composites all reached the maximum, as well as the thermal stability and the storage modulus.


2021 ◽  
Author(s):  
Saba Ghasemizad ◽  
Sajad Pirsa ◽  
Saber Amiri ◽  
Parisa Abdosatri

Abstract In this paper, the effect of adding gum Arabic at levels of 0-5%, and chromium oxide nanoparticles (Cr2O3 NPs) at levels of 0-3%, are investigated on orange peel-based films. The obtained results reveal a significant increase (p<0.05) in water vapor permeability, weight loss, tensile strength, and Young's modulus of film samples by increasing the percentage of both gum and nanoparticles. Moreover, the addition of gum Arabic and Cr2O3 NPs decreases the thickness, water-solubility, L*, a*, b* indexes while increasing the elongation to the breaking point. Furthermore, the moisture content of the film samples was decreased by the addition of nanoparticles, however, the addition of gum Arabic increased this parameter. The obtained results from the morphology of the samples indicated an increase in both roughness and cracks by increasing the percentage of nanoparticles as well as creating a smooth surface with the addition of gum Arabic. Besides, the results of FTIR revealed no new peak in the prepared samples, as compared to the control sample. The results of XRD indicated that the addition of gum Arabic and nanoparticles simultaneously caused the formation of new crystals and increasing the crystallinity of the films. Based on TGA results, the thermal stability of films containing the nanoparticles increased, as compared to the control sample. In the meantime, the addition of gum and nanoparticles increased the antimicrobial properties of the film samples, as compared to the control. Overall, those films created by the orange peel including gum Arabic and Cr2O3 NPs could enhance the mechanical properties and water vapor permeability of the samples.


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