Preparation, characterization, and 3D printing verification of chitosan/halloysite nanotubes/tea polyphenol nanocomposite films

2021 ◽  
Vol 166 ◽  
pp. 32-44
Author(s):  
Yihao Wang ◽  
Shengkui Yi ◽  
Rui Lu ◽  
Dur E. Sameen ◽  
Saeed Ahmed ◽  
...  
Keyword(s):  
3D Printing ◽  
Halloysite Nanotubes ◽  
Nanocomposite Films ◽  
Tea Polyphenol

scholarly journals Printable Alginate Hydrogels with Embedded Network of Halloysite Nanotubes: Effect of Polymer Cross-Linking on Rheological Properties and Microstructure

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4130
Author(s):  
Svetlana A. Glukhova ◽  
Vyacheslav S. Molchanov ◽  
Boris V. Lokshin ◽  
Andrei V. Rogachev ◽  
Alexey A. Tsarenko ◽  
...  
Keyword(s):  
3D Printing ◽  
Rheological Properties ◽  
Shear Thinning ◽  
Halloysite Nanotubes ◽  
Polymer Chains ◽  
Cross Linking ◽  
Saxs Data ◽  
Nanocomposite Hydrogels ◽  
Embedded Network ◽  
The Cross

Rapidly growing 3D printing of hydrogels requires network materials which combine enhanced mechanical properties and printability. One of the most promising approaches to strengthen the hydrogels consists of the incorporation of inorganic fillers. In this paper, the rheological properties important for 3D printability were studied for nanocomposite hydrogels based on a rigid network of percolating halloysite nanotubes embedded in a soft alginate network cross-linked by calcium ions. Particular attention was paid to the effect of polymer cross-linking on these properties. It was revealed that the system possessed a pronounced shear-thinning behavior accompanied by a viscosity drop of 4–5 orders of magnitude. The polymer cross-links enhanced the shear-thinning properties and accelerated the viscosity recovery at rest so that the system could regain 96% of viscosity in only 18 s. Increasing the cross-linking of the soft network also enhanced the storage modulus of the nanocomposite system by up to 2 kPa. Through SAXS data, it was shown that at cross-linking, the junction zones consisting of fragments of two laterally aligned polymer chains were formed, which should have provided additional strength to the hydrogel. At the same time, the cross-linking of the soft network only slightly affected the yield stress, which seemed to be mainly determined by the rigid percolation network of nanotubes and reached 327 Pa. These properties make the alginate/halloysite hydrogels very promising for 3D printing, in particular, for biomedical purposes taking into account the natural origin, low toxicity, and good biocompatibility of both components.

Designing and utilizing 3D printed chitosan/halloysite nanotubes/tea polyphenol composites to maintain the quality of fresh blueberries

2021 ◽  
Vol 74 ◽  
pp. 102808
Author(s):  
Yaowen Liu ◽  
Shengkui Yi ◽  
Dur E. Sameen ◽  
Md Alomgir Hossen ◽  
Jianwu Dai ◽  
...  
Keyword(s):  
Halloysite Nanotubes ◽  
Tea Polyphenol ◽  
3D Printed

scholarly journals Nanocrystalline TiO2 and Halloysite clay mineral composite films prepared by sol-gel method: Synergistic effect and the case of silver modification to the photocatalytic degradation of Basic Blue- 41 azo dye in water.

2014 ◽  
Vol 16 (3) ◽  
pp. 485-498 ◽  
Keyword(s):  
Clay Mineral ◽  
Azo Dye ◽  
Sol Gel ◽  
Composite Films ◽  
Halloysite Nanotubes ◽  
Nanocomposite Films ◽  
Nanocrystalline Tio2 ◽  
Gel Method ◽  
Sol Gel Method ◽  
Glass Substrates

<div> <p>Tubular halloysite clay mineral and nanocrystalline TiO<sub>2 </sub>were incorporated in the preparation of nanocomposite films on glass substrates via sol-gel method at 450&ordm;C. The synthesis involves a simple chemical method employing nonionic surfactant molecule as pore directing agent along with the acetic acid-based sol-gel route without addition of water molecules. Drying and thermal treatment of composite films ensure elimination of organic material and lead to the formation of TiO<sub>2</sub> nanoparticles homogeneously distributed on the surface of the halloysite. Nanocomposite films without cracks of active anatase crystal phase and small crystallite size on halloysite nanotubes are characterized by microscopy techniques and porosimetry methods in order to examine their structural properties. The composite halloysite-TiO<sub>2 </sub>films with variable quantities of halloysite were examined as photocatalysts to the discoloration of Basic Blue 41 azo dye in water. These nanocomposite films proved to be very promising photocatalysts and highly effective to dye&rsquo;s discoloration in spite of small amount of halloysite/TiO<sub>2</sub> catalyst immobilized onto glass substrates. It also has been shown that the efficiency of the halloysite/TiO<sub>2</sub> films could be further improved when silver particles were deposited on their surface after successful adsorption from an aqueous solution of a silver salt and UV reduction of the adsorbed ions.</p> </div> <p>&nbsp;</p>

scholarly journals Insecticide-Releasing LLDPE Films as Greenhouse Cover Materials

2018 ◽  
Author(s):  
Senem Avaz Seven ◽  
Ömer Faruk Tastan ◽  
Cüneyt Erdinç Taş ◽  
Hayriye Ünal ◽  
İkbal Agah Ince ◽  
...  
Keyword(s):  
Testing Machine ◽  
Active Agent ◽  
Halloysite Nanotubes ◽  
Polymeric Films ◽  
Nanocomposite Films ◽  
Biological Assessment ◽  
Linear Low Density Polyethylene ◽  
Scanning Calorimetry ◽  
Agricultural Industry ◽  
Chemical Pesticides

AbstractThe use of chemical pesticides is limited by several public health concerns regarding their toxicity levels and indiscriminate use. Nevertheless, they are still vital components of agricultural industry since no other competitive equivalents to chemical pesticides still exist in terms of efficiency. This study describes the preparation and biological assessment of an insecticide releasing plastic film for agricultural covering purposes. The formulation was prepared by incorporation of deltamethrin loaded, nano-sized halloysite nanotubes into polymeric films. Thermal, morphological, and mechanical properties of films were characterized by Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM) and Universal Testing Machine UTM. Sustained release profiles of the films were evaluated by Thermogravimetric Analysis (TGA). Results reveal that deltamethrin was successfully loaded into halloysite nanotubes and nanotube incorporation enhances the elastic modulus of linear-low density polyethylene (LLDPE) films. In addition, films exhibit controlled release function of the active agent for 32 days. Bioassays of the nanocomposite films with varying deltamethrin doses tested on grasshoppers showed that the LD50 values of the films are 1.85x10−5 g/cm2. Insecticidal activities of films were tested in greenhouse on Medicago Sativa plants contaminated with thrips and aphid. Nanocomposites are observed to repel mature aphids and kill young aphids and thrips.

Structure–property relationship of halloysite nanotubes/ethylene–vinyl acetate–carbon monoxide terpolymer nanocomposites

2016 ◽  
Vol 30 (1) ◽  
pp. 121-140 ◽  
Author(s):  
Gibin George ◽  
M Selvakumar ◽  
Arunjunairaj Mahendran ◽  
S Anandhan
Keyword(s):  
Carbon Monoxide ◽  
Vinyl Acetate ◽  
Volume Resistivity ◽  
Ethylene Vinyl Acetate ◽  
Halloysite Nanotubes ◽  
Filler Loading ◽  
Nanocomposite Films ◽  
Structure Property ◽  
Ionic Charge ◽  
Solution Cast

Poly(ethylene- co-vinyl acetate- co-carbon monoxide) (EVACO)/halloysite nanotube (HNT) nanocomposite films were solution cast. Dispersion of HNTs in the matrix was analyzed by elemental mapping and the role of HNTs on crystallizability, flammability and thermal, mechanical, and electrical properties of the polymer was evaluated. The nature of interaction between the EVACO matrix and HNTs was studied using Fourier transform infrared spectroscopy. The highest tensile strength was observed for the composite with 1% filler loading, whereas the highest crystallinity was observed for that with 3% filler loading. The decay in the tensile properties at higher filler loading was due to agglomeration of HNTs and debonding of polymer–filler interface. The electrical volume resistivity of the composites decreased with HNT loading because of the ionic charge transfer. The direct current electrical resistivity study of the composites proves that the addition of HNT can improve the antistatic properties of the polymer.

scholarly journals Tailoring the Properties of Thermo-Compressed Polylactide Films for Food Packaging Applications by Individual and Combined Additions of Lactic Acid Oligomer and Halloysite Nanotubes

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1976 ◽  
Author(s):  
Sandra Rojas-Lema ◽  
Luis Quiles-Carrillo ◽  
Daniel Garcia-Garcia ◽  
Beatriz Melendez-Rodriguez ◽  
Rafael Balart ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Food Packaging ◽  
Ternary Systems ◽  
Halloysite Nanotubes ◽  
Nanocomposite Films ◽  
Melt Mixing ◽  
Blend Films ◽  
Ultrasound Assisted ◽  
The Individual ◽  
Thermal Stability Of

In this work, films of polylactide (PLA) prepared by extrusion and thermo-compression were plasticized with oligomer of lactic acid (OLA) at contents of 5, 10, and 20 wt%. The PLA sample containing 20 wt% of OLA was also reinforced with 3, 6, and 9 parts per hundred resin (phr) of halloysite nanotubes (HNTs) to increase the mechanical strength and thermal stability of the films. Prior to melt mixing, ultrasound-assisted dispersion of the nanoclays in OLA was carried out at 100 °C to promote the HNTs dispersion in PLA and the resultant films were characterized with the aim to ascertain their potential in food packaging. It was observed that either the individual addition of OLA or combined with 3 phr of HNTs did not significantly affect the optical properties of the PLA films, whereas higher nanoclay contents reduced lightness and induced certain green and blue tonalities. The addition of 20 wt% of OLA increased ductility of the PLA film by nearly 75% and also decreased the glass transition temperature (Tg) by over 18 °C. The incorporation of 3 phr of HNTs into the OLA-containing PLA films delayed thermal degradation by 7 °C and additionally reduced the permeabilities to water and limonene vapors by approximately 8% and 47%, respectively. Interestingly, the highest barrier performance was attained for the unfilled PLA film plasticized with 10 wt% of OLA, which was attributed to a crystallinity increase and an effect of “antiplasticization”. However, loadings of 6 and 9 phr of HNTs resulted in the formation of small aggregates that impaired the performance of the blend films. The here-attained results demonstrates that the properties of ternary systems of PLA/OLA/HNTs can be tuned when the plasticizer and nanofiller contents are carefully chosen and the resultant nanocomposite films can be proposed as a bio-sourced alternative for compostable packaging applications.

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