Solvent-free cellulose nanocrystal fluids for simultaneous enhancement of mechanical properties, thermal conductivity, moisture permeability and antibacterial properties of polylactic acid fibrous membrane

2021 ◽  
Vol 222 ◽  
pp. 109042
Author(s):  
Hui Shen ◽  
Yushan Li ◽  
Wei Yao ◽  
Shiwen Yang ◽  
Ling Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Polylactic Acid ◽  
Antibacterial Properties ◽  
Solvent Free ◽  
Cellulose Nanocrystal ◽  
Fibrous Membrane ◽  
Moisture Permeability

Preparation and study on the optical, mechanical, and antibacterial properties of polylactic acid/ZnO/TiO2 shared nanocomposites

2020 ◽  
Vol 36 (3) ◽  
pp. 285-311
Author(s):  
Ali Tajdari ◽  
Amir Babaei ◽  
Alireza Goudarzi ◽  
Razie Partovi
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Antibacterial Activity ◽  
Optical Properties ◽  
Polylactic Acid ◽  
Field Emission ◽  
Antibacterial Properties ◽  
Hydrolytic Degradation ◽  
Scanning Electron

In this research, first, ZnO nanorods were synthesized by hydrothermal method and characterized in terms of morphological and structural properties by means of field emission scanning electron microscopy, Fourier transform infrared, and X-ray diffraction techniques. Subsequently, polylactic acid/ZnO, polylactic acid/TiO2, and polylactic acid/ZnO/TiO2 nanocomposites with different percentages of nanoparticles and two different types of ZnO morphologies were prepared and their microstructural, optical, mechanical, hydrolytic degradation, and antibacterial properties were investigated. Field emission scanning electron microscopy results of polylactic acid/ZnO and polylactic acid/TiO2 samples showed a proper dispersion and nanoparticle distribution for low percentages (up to 5 wt%) and increased aggregation for the higher percentages. Besides, a large increase in the aggregation tendency was observed for combined nanoparticles (polylactic acid/ZnO/TiO2 nanocomposites). Results of the tensile test, the UV–Vis absorption tests, and the hydrolytic degradation tests of the samples showed an enhanced mechanical (approximately 55% increase in the presence of 3–5 wt% of nanoparticles) and light absorption and degradation (approximately 85% increase in the presence of 3–10 wt% of nanoparticles) for the polylactic acid by incorporating nanoparticles. It was also observed that, in addition to the quality of dispersion and distribution of nanoparticles in the polymeric matrix, the type of morphology of nanoparticles can contribute to the improvement of these properties. The cylindrical morphology of ZnO played a greater role on improving the polylactic acid mechanical properties compared to the spherical ZnO morphology (approximately 20%). On the contrary, the increased polylactic acid optical properties and degradation with ZnO spherical morphology were more pronounced (approximately 60%). Interestingly, when both ZnO and TiO2 were added, a synergistic effect in the case of UV-shielding and degradation rate and alternatively, a detrimental effect on the mechanical properties were detected. (The polylactic acid optical properties increased by about 17% and its degradation more than doubled.) Furthermore, the antibacterial activity of polylactic acid was investigated against the two Gram-positive Listeria monocytogenes and Gram-negative bacteria Escherichia coli by incorporating nanoparticles. The results indicated that as the nanoparticle percentage increases, the antibacterial activity steadily increases.

scholarly journals Evaluation of Nanocomposite Made of Polylactic Acid and Nanocellulose from Carrot Pomace Modified with Silver Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 812 ◽  
Author(s):  
Monika Szymańska-Chargot ◽  
Monika Chylińska ◽  
Piotr M. Pieczywek ◽  
Anna Walkiewicz ◽  
Giorgia Pertile ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mechanical Properties ◽  
Carbon Dioxide ◽  
Silver Nanoparticles ◽  
Polylactic Acid ◽  
Cellulose Nanofibrils ◽  
Antibacterial Properties ◽  
Young Modulus ◽  
Transmission Rates ◽  
Degradation Temperature

In this research, it was proposed to use carrot cellulose nanofibrils (CCNF) isolated from carrot pomace modified with silver nanoparticles (AgNPs) as a filler of polylactic acid (PLA) composites matrix. The new procedure was based on two steps: first, the preparation of nanocellulose modified with metal nanoparticles, and then the combination with PLA. Two concentrations—0.25 mM and 2 mM—of AgNO3 were used to modify CCNF. Then, PLA was mixed with the filler (CCNF/AgNPs) in two proportions 99:1 and 96:4. The influence of CCNF/AgNPs on mechanical, hydrophilic, thermal, and antibacterial properties of obtained nanocomposites was evaluated. The greatest improvement of mechanical properties was observed for composite containing CCNF with 2 mM of AgNPs, which obtained the lowest Young modulus and highest strain at break. The degradation temperature was lower for PLA with CCNF/AgNPs, but crystallization temperature wasn’t influenced. The addition of CCNF/AgNPs also increased hydrophilicity. The transmission rates of oxygen, nitrogen, and carbon dioxide also increased after the addition of CCNF/AgNPs to PLA. The antibacterial function against Escherichia coli and Bacillus cereus was obtained after the addition of AgNPs but only at the contact surface with the material made, suggesting the lack of migration of nanoparticles from the composite.

Polylactic Acid/Halloysite Nanotubes-Titanium Dioxide Nanocomposites: Antibacterial and Mechanical Properties

2021 ◽  
Vol 1021 ◽  
pp. 270-279
Author(s):  
Abdulkader M. Alakrach ◽  
Awad A. Al-Rashdi ◽  
Taha Alqadi ◽  
Mohammed Abdulhakim Al Saadi ◽  
Sam Sung Ting ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
High Efficiency ◽  
Antibacterial Effect ◽  
Control Sample ◽  
Antibacterial Properties ◽  
Halloysite Nanotubes ◽  
Solution Casting ◽  
Elapsed Time ◽  
Solution Casting Method

Polylactic acid (PLA) nanocomposite samples with different properties like mechanical, thermal, barrier and antibacterial properties are good candidates as packaging biomaterials. Unique PLA/TiO2 and PLA/HNTs-TiO2 nanocomposite samples were fabricated by solution casting method. The mechanical and antibacterial properties of PLA/TiO2 and PLA/HNTs-TiO2 samples were investigated with comparing to the pristine PLA film as a control sample. PLA nanocomposite samples with TiO2 nanofillers showed poorer mechanical properties while PLA films with PLA/HNTs-TiO2 showed unique developments, which tensile strength improved by 46% with the incorporation of 5 wt%. The PLA nanocomposites showed a high efficiency to both Gram positive and Gram negative bacteria, significant antibacterial effect being proved after first week elapsed time by comparing to the control sample (presenting no antibacterial effect). By considering the multifunctional characteristics of PLA/TiO2 and PLA/HNTs-TiO2 nanocomposites, the samples produced by solution casting can be considered a favourable alternative as environmental-friendly packaging materials.

scholarly journals Study on Graphene/CNC-Coated Bamboo Pulp Fabric Preparation of Fabrics with Thermal Conductivity

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1265 ◽  
Author(s):  
Feng Yang ◽  
Cuiqin Lan ◽  
Haiming Zhang ◽  
Jian Guan ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Tensile Strength ◽  
Environmentally Friendly ◽  
Cellulose Nanocrystal ◽  
Clothing Industry ◽  
Thermal And Mechanical Properties ◽  
Bamboo Pulp ◽  
Fast Cooling ◽  
Bamboo Pulp Fabric

Functional fabrics have gained attention as an environmentally-friendly synthesis route. In the current study, novelty bamboo pulp fabrics with thermal conductivity properties were prepared by coating the fabric with graphene and cellulose nanocrystal (G/CNC) solutions. The influences of G and CNC concentrations on properties of fabrics were studied. The viscosities of the G/CNC solutions increased with an increase of G contents. G had an obvious thickening effect. Furthermore, compounded fabrics with different G and CNC contents (GCBPFs) were prepared and extensively characterized in terms of thermal and mechanical properties, and morphology. The ultimate thermal conductivity, bursting strength, and tensile strength of the GCBPF were 0.136 W/m·K, 1.514 MPa, and 25.8 MPa, with 4 wt.% CNC and 3 wt.% G contents, respectively. The results demonstrated that the as-fabricated GCBPFs with favorable thermal conductivity could be applied as a novel fast cooling textile for the clothing industry.

Preparation and characterization of solvent-free fluids reinforced and plasticized polylactic acid fibrous membrane

2020 ◽  
Vol 161 ◽  
pp. 122-131 ◽  
Author(s):  
Qiao Yu ◽  
Yi Qin ◽  
Mengyao Han ◽  
Fei Pan ◽  
Lu Han ◽  
...  
Keyword(s):  
Polylactic Acid ◽  
Solvent Free ◽  
Fibrous Membrane

scholarly journals SUSTAINABLE CELLULOSE NANOCRYSTAL REINFORCED CHITOSAN/HPMC BIO-NANOCOMPOSITE FILMS CONTAINING MENTHOL OIL AS PACKAGING MATERIALS

2021 ◽  
Vol 55 (5-6) ◽  
pp. 649-658
Author(s):  
SALAH A. A. MOHAMED ◽  
AHMED SALAMA ◽  
MOHAMED EL-SAKHAWY ◽  
ABDELMAGEED M. OTHMAN
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Food Packaging ◽  
Hydroxypropyl Methylcellulose ◽  
Composite Films ◽  
Antibacterial Properties ◽  
Film Structure ◽  
Cellulose Nanocrystal ◽  
Nanocomposite Films ◽  
Low Oxygen

There is a growing demand to develop biodegradable composite films, with enhanced water resistance, antimicrobial activity, high mechanical properties and low oxygen permeability. In the present study, chitosan/hydroxypropyl methylcellulose (HPMC) films reinforced with cellulose nanocrystal (CNC) and containing menthol oil were prepared for food packaging applications. Menthol oil was selected due to its antibacterial properties, as well as relatively low cost and wide availability. CNC was prepared from bagasse via acid degradation. The bio-composites were prepared through a simple and versatile solution mixing and casting method. The morphology, chemical composition, water absorption, mechanical properties and antibacterial activity of the films were investigated. FTIR spectra were used to evaluate the film structure in terms of the interactions between components. Data showed that the addition of CNC improved the mechanical properties of the formed films and the menthol oil enhanced their antibacterial properties. HPMC and HPMC/CNC reduced the water absorption of the pure chitosan membrane from 70% to 22% and 9-11% by weight, respectively, which makes these constituents a good alternative for producing packaging.

Enhanced moisture permeability and heat dissipation effect of solvent-free boron nitride fluids based polylactic acid fibrous membranes

2021 ◽  
pp. 101001
Author(s):  
Hui Shen ◽  
Junfeng Wang ◽  
Yushan Li ◽  
Long Zheng ◽  
Siwei Xiong ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Polylactic Acid ◽  
Heat Dissipation ◽  
Solvent Free ◽  
Effect Of Solvent ◽  
Moisture Permeability ◽  
Dissipation Effect ◽  
Fibrous Membranes

An analysis of the transport properties and mechanical stability of rapidly solidified Al-Sb alloy

2015 ◽  
Vol 10 (2) ◽  
pp. 2663-2681
Author(s):  
Rizk El- Sayed ◽  
Mustafa Kamal ◽  
Abu-Bakr El-Bediwi ◽  
Qutaiba Rasheed Solaiman
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Melt Spinning ◽  
Elastic Moduli ◽  
Mechanical Stability ◽  
Microstructural Analysis ◽  
Alloy System ◽  
Antimony Content ◽  
The Stability ◽  
Rapidly Solidified

The structure of a series of AlSb alloys prepared by melt spinning have been studied in the as melt–spun ribbons  as a function of antimony content .The stability  of these structures has  been  related to that of the transport and mechanical properties of the alloy ribbons. Microstructural analysis was performed and it was found that only Al and AlSb phases formed for different composition.  The electrical, thermal and the stability of the mechanical properties are related indirectly through the influence of the antimony content. The results are interpreted in terms of the phase change occurring to alloy system. Electrical resistivity, thermal conductivity, elastic moduli and the values of microhardness are found to be more sensitive than the internal friction to the phase changes. 

Incorporation of Iraqi Rocks in the Production of Eco-Friendly Cement Mortar

2020 ◽  
Vol 38 (10A) ◽  
pp. 1522-1530
Author(s):  
Rawnaq S. Mahdi ◽  
Aseel B. AL-Zubidi ◽  
Hassan N. Hashim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Water Absorption ◽  
Structural Properties ◽  
Mechanical Milling ◽  
Cement Mortar ◽  
Cement Mortars

This work reports on the incorporation of Flint and Kaolin rocks powders in the cement mortar in an attempt to improve its mechanical properties and produce an eco-friendly mortar. Flint and Kaolin powders are prepared by dry mechanical milling. The two powders are added separately to the mortars substituting cement partially. The two powders are found to improve the mechanical properties of the mortars. Hardness and compressive strength are found to increase with the increase of powders constituents in the cement mortars. In addition, the two powders affect water absorption and thermal conductivity of the mortar specimens which are desirable for construction applications. Kaolin is found to have a greater effect on the mechanical properties, water absorption, and thermal conductivity of the mortars than Flint. This behavior is discussed and analyzed based on the compositional and structural properties of the rocks powders.

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