scholarly journals A Facile Green Fabrication and Characterization of Cellulose-Silver Nanoparticle Composite Sheets for an Antimicrobial Food Packaging

2021 ◽  
Vol 8 ◽  
Author(s):  
Seongyoung Kwon ◽  
Wooseok Lee ◽  
Jung Wook Choi ◽  
Nattinee Bumbudsanpharoke ◽  
Seonghyuk Ko
Keyword(s):  
Photoelectron Spectroscopy ◽  
Food Packaging ◽  
Cellulose Fiber ◽  
Cellulose Fibers ◽  
Hydroxyl Groups ◽  
Green Approach ◽  
Vis Spectroscopy ◽  
One Step ◽  
The One

The present study focused on a facile and green approach for the one-step synthesis of silver nanoparticles (AgNPs) embedded in hard wood bleached kraft fiber. The hydroxyl groups on the cellulose chain induced ionic silver reduction with additional hydrothermal energy, allowing for the in situ formation and deposition of AgNPs on the cellulose fiber. The white color of the bleached fiber transformed to yellow due to the formation of AgNPs. UV-Vis spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy revealed that the AgNPs were uniformly distributed across the surface of the obtained cellulose fibers. The results indicated that the formation and distribution of AgNPs on surface of cellulose fibers was significantly influenced by the amount and concentration of silver nitrate (AgNO3). The antimicrobial activity of the cellulose-AgNP composite sheet against Escherichia coli was found to be inhibiting. These findings imply that cellulose-AgNP composite sheets can be feasibly used as antimicrobial paper for food packaging.

scholarly journals Effect of Na- and Organo-Modified Montmorillonite/Essential Oil Nanohybrids on the Kinetics of the In Situ Radical Polymerization of Styrene

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 474
Author(s):  
Ioannis S. Tsagkalias ◽  
Alexandra Loukidi ◽  
Stella Chatzimichailidou ◽  
Constantinos E. Salmas ◽  
Aris E. Giannakas ◽  
...  
Keyword(s):  
Essential Oil ◽  
Radical Polymerization ◽  
Food Packaging ◽  
In Situ Polymerization ◽  
Average Molecular Weight ◽  
Monomer Conversion ◽  
Hydroxyl Groups ◽  
Modified Montmorillonite ◽  
Kinetics Of

The great concern about the use of hazardous additives in food packaging materials has shown the way to new bio-based materials, such as nanoclays incorporating bioactive essential oils (EO). One of the still unresolved issues is the proper incorporation of these materials into a polymeric matrix. The in situ polymerization seems to be a promising technique, not requiring high temperatures or toxic solvents. Therefore, in this study, the bulk radical polymerization of styrene was investigated in the presence of sodium montmorillonite (NaMMT) and organo-modified montmorillonite (orgMMT) including thyme (TO), oregano (OO), and basil (BO) essential oil. It was found that the hydroxyl groups present in the main ingredients of TO and OO may participate in side retardation reactions leading to lower polymerization rates (measured gravimetrically by the variation of monomer conversion with time) accompanied by higher polymer average molecular weight (measured via GPC). The use of BO did not seem to affect significantly the polymerization kinetics and polymer MWD. These results were verified from independent experiments using model compounds, thymol, carvacrol and estragol instead of the clays. Partially intercalated structures were revealed from XRD scans. The glass transition temperature (from DSC) and the thermal stability (from TGA) of the nanocomposites formed were slightly increased from 95 to 98 °C and from 435 to 445 °C, respectively. Finally, better dispersion was observed when orgMMT was added instead of NaMMT.

Methanobactin-Mediated One-Step Synthesis of Palladium Nanoparticles

NANO ◽  
2016 ◽  
Vol 11 (06) ◽  
pp. 1650064 ◽  
Author(s):  
Jia-Ying Xin ◽  
Hong-Chen Fan ◽  
Sheng-Fu Ji ◽  
Yan Wang ◽  
Chun-Gu Xia
Keyword(s):  
Photoelectron Spectroscopy ◽  
Palladium Nanoparticles ◽  
Fluorescence Spectra ◽  
Copper Binding ◽  
Secondary Nucleation ◽  
Visible Spectra ◽  
One Step ◽  
Ft Ir ◽  
Uv Visible ◽  
The One

The development of palladium nanoparticles (PdNPs) with a narrow size distribution is an important aspect of nanotechnology. Methanobactin (Mb) is a copper-binding small peptide that appears to function as an agent for copper sequestration and uptake in methanotrophs. Here, Mb was shown to bind and catalytically reduce Pd (II) to Pd (0). The one-step synthesis of monodisperse PdNPs using Mb as both coordination agent and reduction agent is reported. Fluorescence spectra, UV-visible spectra, X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared spectroscopy (FT-IR) suggested that the Mb molecules catalytically reduce Pd (II) to Pd (0) with the concomitant production of PdNPs. The Mb is then adsorbed onto the surface of the PdNPs to form an Mb–PdNPs coordination compound. This avoids secondary nucleation. The PdNPs are small with high monodispersity and are easily synthesized in Mb solution. The PdNPs were extremely stable and resisted aggregation even after several months.

scholarly journals Analysis of the Influence of Fibers on the Formability of Metal Blanks in Manufacturing Processes for Fiber Metal Laminates

2019 ◽  
Vol 3 (1) ◽  
pp. 2 ◽  
Author(s):  
Thomas Mennecart ◽  
Soeren Gies ◽  
Noomane Ben Khalifa ◽  
A. Erman Tekkaya
Keyword(s):  
Contact Forces ◽  
Starting Time ◽  
Fiber Metal Laminate ◽  
Metal Sheets ◽  
Different Types ◽  
One Step ◽  
Fiber Metal ◽  
The One ◽  
Metal Blank

In the one-step manufacturing process for fiber metal laminate parts, the so-called in situ hybridization process, the fabrics are interacting with metal blanks. During deep drawing, the liquid matrix is injected between the metal sheets through the woven fiber layers. The metal blanks can be in contact with dry or with infiltrated fibers. The formability of the blanks is influenced by the variation of the starting time of injection. The reason for that is that, due to high contact forces, the fibers are able to deform the metal surface locally, so that movement and the strain of the blanks is inhibited. To investigate the influence of different fibers on the formability of metals, Nakazima tests are performed. In these tests, two metal blanks are formed with an interlayer of fibers. The results are compared with the formability of two blanks without any interlayer. It is shown that in with fibers between sheets, the formability decreases compared to the formability of two metal blanks without interlayers. Based on a simplified numerical model for different types of fibers, the interactions of the fibers with the metal blank are analyzed. It could be shown that the friction due to contact has more influence than the friction due to the form fit caused by the imprints.

scholarly journals A One-Pot Synthesis and Characterization of Antibacterial Silver Nanoparticle–Cellulose Film

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 440 ◽  
Author(s):  
Qi-Yuan Chen ◽  
Sheng-Ling Xiao ◽  
Sheldon Q. Shi ◽  
Li-Ping Cai
Keyword(s):  
Composite Film ◽  
Food Packaging ◽  
Antibacterial Activities ◽  
Light Transmittance ◽  
Ag Nps ◽  
One Pot ◽  
One Pot Synthesis ◽  
The One

Using N,N-dimethylacetamide (DMAc) as a reducing agent in the presence of PVP-K30, the stable silver nanoparticles (Ag-NPs) solution was prepared by a convenient method for the in situ reduction of silver nitrate. The cellulose–Ag-NPs composite film (CANF) was cast in the same container using lithium chloride (LiCl) giving the Ag-NPs-PVP/DMAc solution cellulose solubility as well as γ-mercaptopropyltrimethoxysilane (MPTS) to couple Ag-NPs and cellulose. The results showed that the Ag-NPs were uniformly dispersed in solution, and the solution had strong antibacterial activities. It was found that the one-pot synthesis allowed the growth of and cross-linking with cellulose processes of Ag-NPs conducted simultaneously. Approximately 61% of Ag-NPs was successfully loaded in CANF, and Ag-NPs were uniformly dispersed in the surface and internal of the composite film. The composite film exhibited good tensile properties (tensile strength could reach up to 86.4 MPa), transparency (light transmittance exceeds 70%), thermal stability, and remarkable antibacterial activities. The sterilization effect of CANF0.04 against Staphylococcus aureus and Escherichia coli exceed 99.9%. Due to low residual LiCl/DMAc and low diffusion of Ag-NPs, the composite film may have potential for applications in food packaging and bacterial barrier.

In-situ regeneration mechanisms of hybrid catalysts in the one-step synthesis of dimethyl ether from syngas

2007 ◽  
Vol 115 (1-2) ◽  
pp. 23-26 ◽  
Author(s):  
Youshun Luan ◽  
Hengyong Xu ◽  
Chunying Yu ◽  
Wenzhao Li ◽  
Shoufu Hou
Keyword(s):  
Dimethyl Ether ◽  
Hybrid Catalysts ◽  
In Situ Regeneration ◽  
One Step ◽  
The One ◽  
Synthesis Of Dimethyl Ether

scholarly journals 1-(4-Nitrophenyl)-1H-1,2,3-Triazole-4-carbaldehyde: Scalable Synthesis and Its Use in the Preparation of 1-Alkyl-4-Formyl-1,2,3-triazoles

Organics ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 404-414
Author(s):  
Tomas Opsomer ◽  
Kaat Valkeneers ◽  
Ana Ratković ◽  
Wim Dehaen
Keyword(s):  
One Pot ◽  
Complete Hydrolysis ◽  
One Step ◽  
Synthetic Intermediates ◽  
Cornforth Rearrangement ◽  
Scalable Synthesis ◽  
The One ◽  
Novel Applications ◽  
Hydrolysis Of

1,2,3-Triazole-4-carbaldehydes are useful synthetic intermediates which may play an important role in the discovery of novel applications of the 1,2,3-triazole moiety. In this work, a one-step multigram scale synthesis of 4-formyl-1-(4-nitrophenyl)-1H-1,2,3-triazole (FNPT) as a preferred reagent for the synthesis of 1-alkyl-4-formyltriazoles is described, making use of the commercially available 3-dimethylaminoacrolein and 4-nitrophenyl azide. Next, the earlier reported reaction of FNPT with alkylamines is further explored, and for hexylamine, the one-pot sequential cycloaddition and Cornforth rearrangement is demonstrated. In addition, a useful protocol for the in situ diazotization of 4-nitroaniline is provided. This facilitated the complete hydrolysis of rearranged 4-iminomethyl-1,2,3-triazoles and allowed for the recycling of 4-nitrophenyl azide.

Pd/meso-CoO derived from in situ reduction of the one-step synthesized Pd/meso-Co3O4: high-performance catalysts for benzene combustion

2019 ◽  
Vol 43 (31) ◽  
pp. 12358-12368 ◽  
Author(s):  
Xingtian Zhao ◽  
Ran Zhang ◽  
Yuxi Liu ◽  
Jiguang Deng ◽  
Peng Xu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
High Performance ◽  
Oxygen Activation ◽  
In Situ Reduction ◽  
Templating Method ◽  
One Step ◽  
The One

The 0.93Pd/meso-CoO is prepared via in situ reduction of 0.85Pd/meso-Co3O4 derived from KIT-6-templating method. The excellent catalytic activity of 0.93Pd/meso-CoO is related to the formed Pd0 species and good oxygen activation ability.

Cellulose nanocrystals/silver nanoparticles: in-situ preparation and application in PVA films

Holzforschung ◽  
2020 ◽  
Vol 74 (5) ◽  
pp. 523-528 ◽  
Author(s):  
Li Fan ◽  
Hui Zhang ◽  
Mengxi Gao ◽  
Meng Zhang ◽  
Pengtao Liu ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Cellulose Nanocrystals ◽  
Food Packaging ◽  
Moisture Absorption ◽  
Antibacterial Properties ◽  
Nanocomposite Films ◽  
Hydroxyl Groups ◽  
In Situ Preparation ◽  
The Many

AbstractWith the increasing application of polyvinyl alcohol (PVA) films in the field of food packaging, it is important to improve its mechanical and antibacterial properties. This paper focuses on the preparation of PVA nanocomposite films and how their properties are affected by a silver-loaded nanocellulose solution. Cellulose nanocrystals (CNCs) were used as both the carrier and the dispersant of silver nanoparticles (AgNPs) prepared using glucose as the reducing agent. Ag+ was stabilized by the many hydroxyl groups located in the CNCs, and then the Ag+ was reduced to AgNPs in situ. After addition of silver-loaded nanocellulose, the tensile strength of the CNC-PVA-AgNP films increased from 47 MPa to 73 MPa, and the nanocomposite films displayed reduced moisture absorption and good antibacterial properties.

Sign in / Sign up

Export Citation Format

Share Document