A facile one-pot route to elastomeric vitrimers with tunable mechanical performance and superior creep resistance

Aluminum phosphates coated sepiolite nanocomposite was fabricated via a simple one-pot heterogeneous precipitation strategy, and the effects of aluminum phosphates on the morphology of aluminum phosphates coated sepiolite were investigated. Moreover, the effect of aluminum phosphates coated sepiolite on the flame-retardant behavior, mechanical properties, and thermal stability of epoxy resin have been discussed. The results indicated that the introduction of only 20 wt% aluminum phosphates coated sepiolite in epoxy resin increased the limited oxygen index from 21.8% to 30.1%, thus the material met the UL-94 V-0 rating. Thermogravimetric analyses revealed that char yield increased in the presence of aluminum phosphates coated sepiolite form thermally stable carbonaceous char. Aluminum phosphates–coated sepiolite could improve the mechanical performance, thermal stability of epoxy resin.

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Zwitterionic Nanocellulose-Based Membranes for Organic Dye Removal

Materials ◽

10.3390/ma12091404 ◽

2019 ◽

Vol 12 (9) ◽

pp. 1404 ◽

Cited By ~ 11

Author(s):

Carla Vilela ◽

Catarina Moreirinha ◽

Adelaide Almeida ◽

Armando J. D. Silvestre ◽

Carmen S. R. Freire

Keyword(s):

Pathogenic Bacteria ◽

Mechanical Performance ◽

Organic Dyes ◽

Dye Adsorption ◽

High Water ◽

Water Soluble ◽

Water Remediation ◽

Nanocomposite Membranes ◽

Porous Network ◽

One Pot

The development of efficient and environmentally-friendly nanomaterials to remove contaminants and pollutants (including harmful organic dyes) ravaging water sources is of major importance. Herein, zwitterionic nanocomposite membranes consisting of cross-linked poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and bacterial nanocellulose (BNC) were prepared and tested as tools for water remediation. These nanocomposite membranes fabricated via the one-pot polymerization of the zwitterionic monomer, 2-methacryloyloxyethyl phosphorylcholine, within the BNC three-dimensional porous network, exhibit thermal stability up to 250 °C, good mechanical performance (Young’s modulus ≥ 430 MPa) and high water-uptake capacity (627%–912%) in different pH media. Moreover, these zwitterionic membranes reduced the bacterial concentration of both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) pathogenic bacteria with maxima of 4.3– and 1.8–log CFU reduction, respectively, which might be a major advantage in reducing or avoiding bacterial growth in contaminated water. The removal of two water-soluble model dyes, namely methylene blue (MB, cationic) and methyl orange (MO, anionic), from water was also assessed and the results demonstrated that both dyes were successfully removed under the studied conditions, reaching a maximum of ionic dye adsorption of ca. 4.4–4.5 mg g−1. This combination of properties provides these PMPC/BNC nanocomposites with potential for application as antibacterial bio-based adsorbent membranes for water remediation of anionic and cationic dyes.

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High Mechanical Performance Based on Physically Linked Double Network (DN) Hydrogels

Materials ◽

10.3390/ma12203333 ◽

2019 ◽

Vol 12 (20) ◽

pp. 3333 ◽

Cited By ~ 1

Author(s):

Niu ◽

Zhang ◽

Shen ◽

Sheng ◽

Fu ◽

...

Keyword(s):

Mechanical Properties ◽

Mechanical Performance ◽

Design Strategy ◽

Hydroxyethyl Cellulose ◽

One Pot ◽

Double Network ◽

Polyhydroxy Compounds ◽

Potential Applications ◽

Cellulose Composite ◽

Biomedical Fields

A new design strategy was proposed to improve the mechanical performance of double network (DN) hydrogels by introducing polyhydroxy compounds into the DN structure and form a physically linked double network through the interaction of hydrogen bonding. Herein, agar/poly(acrylic acid)/hydroxyethyl cellulose composite hydrogels could be prepared by a simple one-pot method. The resulting hydrogels exhibit highly mechanical properties and excellent recoverability, which have potential applications in biomedical fields.

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Antimicrobial and Conductive Nanocellulose-Based Films for Active and Intelligent Food Packaging

Nanomaterials ◽

10.3390/nano9070980 ◽

2019 ◽

Vol 9 (7) ◽

pp. 980 ◽

Cited By ~ 16

Author(s):

Carla Vilela ◽

Catarina Moreirinha ◽

Eddy M. Domingues ◽

Filipe M. L. Figueiredo ◽

Adelaide Almeida ◽

...

Keyword(s):

Food Packaging ◽

Mechanical Performance ◽

Barrier Properties ◽

High Water ◽

Nitrogen Atmosphere ◽

Nanocomposite Films ◽

One Pot ◽

Glycol Diacrylate ◽

Active Food Packaging ◽

The One

Bacterial nanocellulose (BNC) is becoming an important substrate for engineering multifunctional nanomaterials with singular and tunable properties for application in several domains. Here, antimicrobial conductive nanocomposites composed of poly(sulfobetaine methacrylate) (PSBMA) and BNC were fabricated as freestanding films for application in food packaging. The nanocomposite films were prepared through the one-pot polymerization of sulfobetaine methacrylate (SBMA) inside the BNC nanofibrous network and in the presence of poly(ethylene glycol) diacrylate as cross-linking agent. The ensuing films are macroscopically homogeneous, more transparent than pristine BNC, and present thermal stability up to 265 °C in a nitrogen atmosphere. Furthermore, the films have good mechanical performance (Young’s modulus ≥ 3.1 GPa), high water-uptake capacity (450–559%) and UV-blocking properties. The zwitterion film with 62 wt.% cross-linked PSBMA showed bactericidal activity against Staphylococcus aureus (4.3–log CFU mL−1 reduction) and Escherichia coli (1.1–log CFU mL−1 reduction), and proton conductivity ranging between 1.5 × 10−4 mS cm−1 (40 °C, 60% relative humidity (RH)) and 1.5 mS cm−1 (94 °C, 98% RH). Considering the current set of properties, PSBMA/BNC nanocomposites disclose potential as films for active food packaging, due to their UV-barrier properties, moisture scavenging ability, and antimicrobial activity towards pathogenic microorganisms responsible for food spoilage and foodborne illness; and also for intelligent food packaging, due to the proton motion relevant for protonic-conduction humidity sensors that monitor food humidity levels.

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Synthesis of self-assembled nacre-like materials with 3D periodic layers from nanochitin via hydrogelation and mineralization

10.21203/rs.3.rs-239873/v1 ◽

2021 ◽

Author(s):

Junhua Xu ◽

Liang Liu ◽

Juan Yu ◽

Yujun Zou ◽

Wenhui Pei ◽

...

Keyword(s):

Optical Waveguides ◽

Mechanical Performance ◽

Light Transmission ◽

One Pot ◽

Biomedical Material ◽

Directional Diffusion ◽

Brick And Mortar ◽

One Step ◽

Self Assembled ◽

Periodic Materials

Abstract Here introduced a route for the synthesis of 3D structures that display a mechanical strength that competes with that of the toughest materials found in nature. Following the “brick-and-mortar” biomineralization typical of nacre, self-stratified, periodic materials are obtained by one-step ion diffusion gradient and hydrogelation of nanochitin with simultaneous mineral coprecipitation. Specifically, under appropriate electrolyte conditions, hydroxyapatite (HA) microspheres grow in an organic network formed from partially deacetylated chitin nanofibers (NCh), resulting in periodic stacking of mineralized (HA) and non-mineralized (NCh) layers. By directional diffusion, customizable 3D shapes are self-assembled and demonstrated to function as optical waveguides with selective light transmission at interfaces. Upon hot pressing, the resulting solid structures exhibit a superb mechanical performance while being biocompatible (tested with chondrogenic ATDC5 cells as a model for physiological mineralization). Overall, a shape-controlled, one-pot biomineralization method was proposed that achieves hierarchical, periodic and strong “nacre-like” structures suitable as biomedical material.

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