Papain Covalently Immobilized on Chitosan–Clay Nanocomposite Films: Application in Synthetic and Real White Wine

Increasing attention has been recently paid to the development of nanocomposite materials for food application as new tool to enhance the mechanical and thermal properties of polymers. In this study, novel chitosan–clay nanocomposite films were produced as carriers for the covalent immobilization of papain, by using a fixed amount of chitosan (1% w/v) and a food-grade activated montmorillonite (Optigel, OPT) or a high-purity unmodified montmorillonite (SMP), in four different weight percentages with respect to chitosan (i.e., 20, 30, 50, 70% w/w). Both nanoclays (OPT and SMP) improved the mechanical properties of the obtained nanocomposites, and the OPT films showed the highest Young modulus and mechanical resistance (σmax). The nanocomposites were used as carriers for the covalent immobilization of papain, which was preliminarily characterized in model wine towards a synthetic substrate, showing the highest efficiency in the release of the reaction product when it was bound on OPT-30 and OPT-50 films. Finally, the latter biocatalyst (papain on OPT-50 film) was applied for the protein stabilization of two different unfined white wines, and it efficiently reduced both the haze potential and the protein content.

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Nanocomposites for Food Packaging Applications: An Overview

Nanomaterials ◽

10.3390/nano11010010 ◽

2020 ◽

Vol 11 (1) ◽

pp. 10

Author(s):

Jawad Sarfraz ◽

Tina Gulin-Sarfraz ◽

Julie Nilsen-Nygaard ◽

Marit Kvalvåg Pettersen

Keyword(s):

Polymer Nanocomposites ◽

Circular Economy ◽

Food Packaging ◽

Antioxidant Properties ◽

Nanocomposite Materials ◽

Consumer Acceptability ◽

Special Focus ◽

Packaging Materials ◽

Mechanical And Thermal Properties ◽

Low Concentrations

There is a strong drive in industry for packaging solutions that contribute to sustainable development by targeting a circular economy, which pivots around the recyclability of the packaging materials. The aim is to reduce traditional plastic consumption and achieve high recycling efficiency while maintaining the desired barrier and mechanical properties. In this domain, packaging materials in the form of polymer nanocomposites (PNCs) can offer the desired functionalities and can be a potential replacement for complex multilayered polymer structures. There has been an increasing interest in nanocomposites for food packaging applications, with a five-fold rise in the number of published articles during the period 2010–2019. The barrier, mechanical, and thermal properties of the polymers can be significantly improved by incorporating low concentrations of nanofillers. Furthermore, antimicrobial and antioxidant properties can be introduced, which are very relevant for food packaging applications. In this review, we will present an overview of the nanocomposite materials for food packaging applications. We will briefly discuss different nanofillers, methods to incorporate them in the polymer matrix, and surface treatments, with a special focus on the barrier, antimicrobial, and antioxidant properties. On the practical side migration issues, consumer acceptability, recyclability, and toxicity aspects will also be discussed.

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Thermal and mechanical characterization of a new material based on two gypsums from different localities : High Atlas of Marrakech and Safi Basin, Morocco

10.5194/egusphere-egu21-11102 ◽

2021 ◽

Author(s):

imane baba ◽

Mounsif Ibnoussina ◽

Omar Witam ◽

Latifa Saadi

Keyword(s):

Setting Time ◽

Density Measurement ◽

Mechanical Resistance ◽

Mechanical And Thermal Properties ◽

Low Carbon ◽

X Ray Diffraction ◽

High Atlas ◽

New Material ◽

Indoor Comfort

Over the last few decades, the construction industry has become interested in materials that are durable, environmentally friendly and easily recyclable. This interest is due to the advantages these materials offer, among others local availability, low carbon footprint, energy efficiency and indoor comfort. The objective of this work is to study the properties of plasters prepared from a mixture of two types of gypsum. We were interested in the evolution of thermal conductivity, mechanical resistance and setting time as a function of the percentage of addition.Two types of gypsum were studied, the first one belongs to the Safi basin and the second one comes from the High Atlas of Marrakech.The characterization of the gypsums was necessary to determine its physical and geotechnical properties, its mineralogy, its thermal behavior and its microscopic structure. Several analyses were developed such as density measurement by pycnometer, X-ray diffraction, infrared spectroscopy and scanning electron microscopy.We have made samples, of standardized dimensions, of mixtures based on both types of plaster. The water/gypsum mass ratio was set at 0.75.The results revealed that the properties of gypsum as well as the percentage of addition affect the mechanical and thermal properties and the setting time of the composite material. The addition of the High Atlas gypsum of Marrakech allowed improving the material in terms of thermal insulation. The results of the other tests will be communicated later.

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Development of Novel Thin Polycaprolactone (PCL)/Clay Nanocomposite Films with Antimicrobial Activity Promoted by the Study of Mechanical, Thermal, and Surface Properties

Polymers ◽

10.3390/polym13183193 ◽

2021 ◽

Vol 13 (18) ◽

pp. 3193

Author(s):

Sylva Holešová ◽

Karla Čech Čech Barabaszová ◽

Marianna Hundáková ◽

Michaela Ščuková ◽

Kamila Hrabovská ◽

...

Keyword(s):

Antimicrobial Activity ◽

Surface Properties ◽

Food Packaging ◽

Synergistic Effects ◽

Nanocomposite Films ◽

Mechanical Resistance ◽

X Ray Diffraction ◽

Microbial Strains ◽

And Storage ◽

Structure Properties

Infection with pathogenic microorganisms is of great concern in many areas, especially in healthcare, but also in food packaging and storage, or in water purification systems. Antimicrobial polymer nanocomposites have gained great popularity in these areas. Therefore, this study focused on new approaches to develop thin antimicrobial films based on biodegradable polycaprolactone (PCL) with clay mineral natural vermiculite as a carrier for antimicrobial compounds, where the active organic antimicrobial component is antifungal ciclopirox olamine (CPX). For possible synergistic effects, a sample in combination with the inorganic antimicrobial active ingredient zinc oxide was also prepared. The structures of all the prepared samples were studied by X-ray diffraction, FTIR analysis and, predominantly, by SEM. The very different structure properties of the prepared nanofillers had a fundamental influence on the final structural arrangement of thin PCL nanocomposite films as well as on their mechanical, thermal, and surface properties. As sample PCL/ZnOVER_CPX possessed the best results for antimicrobial activity against examined microbial strains, the synergic effect of CPX and ZnO combination on antimicrobial activity was proved, but on the other hand, its mechanical resistance was the lowest.

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Comparative Study of Protein Stabilization in White Wine Using Zirconia and Bentonite: Physicochemical and Wine Sensory Analysis

Journal of Agricultural and Food Chemistry ◽

10.1021/jf062632w ◽

2006 ◽

Vol 54 (26) ◽

pp. 9955-9958 ◽

Cited By ~ 28

Author(s):

Fernando N. Salazar ◽

Isabel Achaerandio

Keyword(s):

Comparative Study ◽

Sensory Analysis ◽

White Wine ◽

Protein Stabilization

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Mechanical and thermal properties of a nanocomposite material which epoxy based and reinforced with polyvinyl alcohol nano fibers contained multiwalled carbon nanotube

Journal of Composite Materials ◽

10.1177/0021998320969793 ◽

2020 ◽

pp. 002199832096979

Author(s):

Fatih Yıldırım ◽

Necati Ataberk ◽

Mürsel Ekrem

Keyword(s):

Thermal Properties ◽

Polyvinyl Alcohol ◽

Tensile Tests ◽

Nanocomposite Materials ◽

Uniaxial Tensile ◽

Mechanical And Thermal Properties ◽

Multiwalled Carbon ◽

Number Of Layers ◽

Electrospinning Method ◽

Carbon Nano Tube

In this study, the thermal and mechanical properties of nanocomposite materials were investigated. Produced nanocomposite materials are epoxy-based and reinforced with Multiwalled Carbon Nano Tube dopped polyvinyl alcohol (PVA) nanofibers. Nanofibers were produced by the electrospinning method. Nanofibers were used for reinforcement as 5, 10, and 15 number of layers. These nanocomposite materials were subjected to uniaxial tensile tests at constant tensile speed in accordance with ASTM D882-02 standards. Tensile strength, elasticity modulus, Poisson's ratio, and toughness values were obtained and these values were compared with the values of reference pure epoxy samples without the nanofiber. For obtaining the thermal properties of the samples Thermogravimetric and Differential Thermal Analysis were performed. In order to investigate the damage mechanisms, the fractured tensile test specimens' surfaces were visualized by Scanning Electron Microscopy. Mechanical and thermal properties of the epoxy were improved by using the PVA nanofibers dopped the MWCNT.

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Hydroxylated boron nitride nanotube‐reinforced polyvinyl alcohol nanocomposite films with simultaneous improvement of mechanical and thermal properties

Polymer Composites ◽

10.1002/pc.25785 ◽

2020 ◽

Vol 41 (12) ◽

pp. 5182-5194

Author(s):

Xiaolong Lu ◽

Pranjal Nautiyal ◽

Jenniffer Bustillos ◽

Archana Loganathan ◽

Cheng Zhang ◽

...

Keyword(s):

Thermal Properties ◽

Boron Nitride ◽

Polyvinyl Alcohol ◽

Nanocomposite Films ◽

Mechanical And Thermal Properties ◽

Boron Nitride Nanotube

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Polymer-Single Wall Carbon Nanotube Composites for Potential Spacecraft Applications

MRS Proceedings ◽

10.1557/proc-706-z3.30.1 ◽

2001 ◽

Vol 706 ◽

Cited By ~ 17

Author(s):

Cheol Park ◽

Zoubeida Ounaies ◽

Kent A. Watson ◽

Kristin Pawlowski ◽

Sharon E. Lowther ◽

...

Keyword(s):

Electrical Conductivity ◽

Carbon Nanotube ◽

Composite Films ◽

Polymeric Materials ◽

Polymer Nanocomposite ◽

Weight Percent ◽

Nanocomposite Films ◽

Mechanical And Thermal Properties ◽

Single Wall Carbon Nanotube ◽

Single Wall Carbon

AbstractPolymer-single wall carbon nanotube (SWNT) composite films were prepared and characterized as part of an effort to develop polymeric materials with improved combinations of properties for potential use on future spacecraft. Next generation spacecraft will require ultra-lightweight materials that possess specific and unique combinations of properties such as radiation and atomic oxygen resistance, low solar absorptivity, high thermal emissitivity, electrical conductivity, tear resistance, ability to be folded and seamed, and good mechanical properties. The objective of this work is to incorporate sufficient electrical conductivity into space durable polyimides to mitigate static charge build-up. The challenge is to obtain this level of conductivity (10-8 S/cm) without degrading other properties of importance, particularly optical transparency. Several different approaches were attempted to fully disperse the SWNTs into the polymer matrix. These included high shear mixing, sonication, and synthesizing the polymers in the presence of pre-dispersed SWNTs. Acceptable levels of conductivity were obtained at loading levels less than one tenth weight percent SWNT without significantly sacrificing optical properties. Characterization of the nanocomposite films and the effect of SWNT concentration and dispersion on the conductivity, solar absorptivity, thermal emissivity, mechanical and thermal properties were discussed. Fibers and non-woven porous mats of SWNT reinforced polymer nanocomposite were produced using electrospinning.

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Assessment of Potential Effects of Common Fining Agents Used for White Wine Protein Stabilization

American Journal of Enology and Viticulture ◽

10.5344/ajev.2012.12016 ◽

2012 ◽

Vol 63 (4) ◽

pp. 574-578 ◽

Cited By ~ 18

Author(s):

Ricardo Chagas ◽

Sara Monteiro ◽

Ricardo Boavida Ferreira

Keyword(s):

White Wine ◽

Protein Stabilization ◽

Fining Agents

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Study the effect of CaCO3 nanoparticles on physical properties of biopolymer blend

Iraqi Journal of Physics (IJP) ◽

10.30723/ijp.v16i39.97 ◽

2019 ◽

Vol 16 (39) ◽

pp. 11-22

Author(s):

K. J. Mohammed

Keyword(s):

Thermal Conductivity ◽

Tensile Strength ◽

Young’S Modulus ◽

Polymer Blend ◽

Young's Modulus ◽

Antibacterial Properties ◽

Young Modulus ◽

Nanocomposite Films ◽

Caco3 Nanoparticles ◽

Mechanical Durability

Chitosan (CH) / Poly (1-vinylpyrrolidone-co-vinyl acetate) (PVP-co-VAc) blend (1:1) and nanocomposites reinforced with CaCO3 nanoparticles were prepared by solution casting method. FTIR analysis, tensile strength, Elongation, Young modulus, Thermal conductivity, water absorption and Antibacterial properties were studied for blend and nanocomposites. The tensile results show that the tensile strength and Young’s modulus of the nanocomposites were enhanced compared with polymer blend [CH/(PVP-co-VAc)] film. The mechanical properties of the polymer blend were improved by the addition of CaCO3 with significant increases in Young’s modulus (from 1787 MPa to ~7238 MPa) and tensile strength (from 47.87 MPa to 79.75 MPa). Strong interfacial bonding between the CaCO3 nanoparticles and the [CH/(PVP-co-VAc)), homogenous distribution of the nanoparticles in the polymer blend, are assistance of noticeably raised mechanical durability. The thermal conductivity of the polymer blend and CaCO3 nanocomposite films show that it decreased in the adding of nanoparticle CaCO3. The solvability measurements display that the nanocomposite has promoted water resistance. The weight gain lowered with the increase of nano CaCO3. Blending chitosan CH with (PVP-co-VAc) enhanced strength and young modules of the nanocomposites and increased the absorption of water because hydrophilic of the blended polymers films. The effect of two types of positive S.aurous and negative E. coli was studied. The results showed that the nanocomposites were effective for both types, where the activity value ranged from (12 ~ 21). The best results were found for S.aurous bacteria.

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Predictable Models and Experimental Measurements for Electric Properties of Polypropylene Nanocomposite Films

International Journal of Electrical and Computer Engineering (IJECE) ◽

10.11591/ijece.v6i1.pp120-129 ◽

2016 ◽

Vol 6 (1) ◽

pp. 120 ◽

Cited By ~ 1

Author(s):

Ahmed Thabet ◽

Youssef A. Mobarak

Keyword(s):

Fumed Silica ◽

Cost Effective ◽

Nanocomposite Materials ◽

Small Addition ◽

Electric Properties ◽

Nanocomposite Films ◽

Experimental Measurements ◽

Effective Energy ◽

Frequency Range ◽

Industrial Materials

This paper processed and characterized cost-fewer polypropylene (PP) nanocomposite films; an experimental work has been investigated for studying the electric properties of the new nanocomposite materials and compared with unfilled industrial materials in a frequency range up to 1 kHz. A small addition of nanoparticles (clay, and fumed silica) to polypropylene showed appreciable improvement in the electric reactance and conductance at different frequency up to 1kHz, in addition, an electric spectroscopy has been measured the electric properties of polypropylene with and without nanoparticles under variant temperatures (20°C, and 60°C). Cambridge Engineering Selector (CES) program were carried out the electrical/mechanical predictable models for the suggested materials. Finally, this paper leads to synthesize electrical insulating polypropylene nanocomposite films where the electrical properties are properly maintained in order to achieve more cost-effective, energy-effective and hence environmentally better materials for the electrical insulation technology.

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