Development of highly oil-absorbent polylactic-acid microfibers with a nanoporous structure via simple one-step centrifugal spinning

2021 ◽  
pp. 120156
Author(s):  
Linmei Zhang ◽  
Chieko Narita ◽  
Yuki Himeda ◽  
Hidekazu Honma ◽  
Kazushi Yamada
Keyword(s):  
Polylactic Acid ◽  
Nanoporous Structure ◽  
Centrifugal Spinning ◽  
One Step ◽  
Oil Absorbent

scholarly journals Preparation of recyclable corn straw fiber as oil absorbent via a one-step direct modification

2021 ◽  
Vol 8 (1) ◽  
pp. 015506
Author(s):  
Yanlong Shi ◽  
Xiaojuan Feng ◽  
Ruihua Yang
Keyword(s):  
Corn Straw ◽  
Direct Modification ◽  
One Step ◽  
Oil Absorbent

scholarly journals Impact of the Incorporation of Nano-Sized Cellulose Formate on the End Quality of Polylactic Acid Composite Film

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Yidong Zhang ◽  
Chao Liu ◽  
Meiyan Wu ◽  
Zhenqiu Li ◽  
Bin Li
Keyword(s):  
Composite Film ◽  
Polylactic Acid ◽  
Composite Films ◽  
Crystallinity Index ◽  
Regenerated Cellulose ◽  
Fundamental Study ◽  
One Step ◽  
Hydrolysis Of ◽  
Better Than

Polylactic acid (PLA) films with good sustainable and biodegradable properties have been increasingly explored recently, while the poor mechanical property of PLA limits its further application. Herein, three kinds of nano-sized cellulose formate (NCF: cellulose nanofibril (CNF), cellulose nanocrystal (CNC), and regenerated cellulose formate (CF)) with different properties were fabricated via a one-step formic acid (FA) hydrolysis of tobacco stalk, and the influence of the properties of NCF with different morphologies, crystallinity index (CrI), and degree of substitution (DS) on the end quality of PLA composite film was systematically compared. Results showed that the PLA/CNC film showed the highest increase (106%) of tensile strength compared to the CNF- and CF-based films, which was induced by the rod-like CNC with higher CrI. PLA/CF film showed the largest increase (50%) of elongation at the break and more even surface, which was due to the stronger interfacial interaction between PLA and the CF with higher DS. Moreover, the degradation property of PLA/CNF film was better than that of other composite films. This fundamental study was very beneficial for the development of high-quality, sustainable packaging as an alternative to petroleum-based products.

scholarly journals Fiber Forming Capability of Binary and Ternary Compositions in the Polymer System: Bacterial Cellulose–Polycaprolactone–Polylactic Acid

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1148 ◽  
Author(s):  
Mehmet Onur Aydogdu ◽  
Esra Altun ◽  
Jubair Ahmed ◽  
Oguzhan Gunduz ◽  
Mohan Edirisinghe
Keyword(s):  
Mechanical Properties ◽  
Bacterial Cellulose ◽  
Polylactic Acid ◽  
Polymer System ◽  
Product Yield ◽  
Fiber Morphology ◽  
Fibrous Scaffold ◽  
Centrifugal Spinning ◽  
High Concentrations ◽  
Suitable System

Bacterial Cellulose (BC) has over recent decades shown great versatility in wound healing dressings, but is difficult to spin fibers with at high concentrations. An investigation into the preparation of bandage-like fibrous meshes is carried out to determine the optimal blend of polycaprolactone (PCL) and polylactic acid (PLA) as a suitable carrier for BC. Using a simple centrifugal spinning setup, polymer blends of PCL, PLA and BC are investigated as a ternary system to determine the most suitable composition with a focus on achieving maximal BC concentration. It is found that BC content in the fibers above 10 wt % reduced product yield. By creating blends of PLA-PCL fibers, we can create a more suitable system in terms of yield and mechanical properties. The fibrous samples are examined for yield, fiber morphology using scanning electron microscopy, mechanical properties using tensile testing and chemical characteristics using Fourier-transform infrared spectroscopy. A fibrous scaffold with > 30 wt % BC was produced with enhanced mechanical properties owing to the blending of PLA and PCL.

scholarly journals One-Step Polylactic Acid Screen-Printing Microfluidic Paper-Based Analytical Device: Application for Simultaneous Detection of Nitrite and Nitrate in Food Samples

Chemosensors ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 44 ◽  
Author(s):  
Siriwan Teepoo ◽  
Supattra Arsawiset ◽  
Pitchayatida Chanayota
Keyword(s):  
Polylactic Acid ◽  
Screen Printing ◽  
Colorimetric Detection ◽  
Simultaneous Detection ◽  
Reference Method ◽  
Cost Effective ◽  
Food Samples ◽  
Device Fabrication ◽  
Experimental Conditions ◽  
One Step

In this work, we report a one-step approach for fabricating screened-printed microfluidic paper-based analytical devices (μPADs) using polylactic acid as a new hydrophobic material. A polylactic acid solution was screen printed onto chromatography papers to create hydrophobic patterns for fluidic channels. The optimal polylactic acid concentration for successful device fabrication is 9% w/v. The μPADs were fabricated within 2 min and provided high reproducibility and stability. The utility of polylactic acid screen-printing was demonstrated for the simultaneous detection of nitrite and nitrate using colorimetric detection. Under optimized experimental conditions, the detection limits and the linear ranges, respectively, were 1.2 mg L−1 and 2–10 mg L−1 for nitrite and 3.6 mg L−1 and 10–50 mg L−1 for nitrate. The detection times for both ions were found to be within 12 min. The developed μPAD was applied for the simultaneous determination of these ions in food samples, and no significant differences in the analytical results were observed compared to those of the reference method. The polylactic acid screen-printing approach presented here provides a simple, rapid, and cost-effective alternative fabrication method for fabricating μPADs.

scholarly journals Study on Reinforced Modification of Polylactic Acid by New Hyperbranched Polyamide

2021 ◽  
Author(s):  
Jianjian Sun ◽  
Yansong Huang ◽  
Yu juan Jin ◽  
Lu Wang ◽  
Huafeng Tian
Keyword(s):  
Polylactic Acid ◽  
Raw Materials ◽  
Extrusion Process ◽  
Injection Molding Process ◽  
Molding Process ◽  
Twin Screw ◽  
Chemical Crosslinks ◽  
One Step ◽  
The Impact ◽  
Hyperbranched Polyamide

Abstract In order to achieve enhanced physical performance of polylactic acid (PLA), the hyperbranched polyamide (HBPA) was synthesized by "one-step" as raw materials, and added as a modifier to the PLA matrix. The HBPA/PLA blend was prepared through the twin screw extrusion process and the injection molding process. The results showed that, compared with pure PLA, the tensile strength of HBPA/PLA blends increased by 41.8% while the elongation at break and the impact strength basically unchanged. The addition of HBPA does not affect the glass transition temperature (Tg) and crystallization of PLA significantly, but can improve the thermal deformation temperature of PLA. HBPA acted as a nucleant for PLA during iso-temperature crystallization. HBPA could form hydrogen bonds and chemical crosslinks with PLA, thus exhibits excellent reinforcing effect for PLA.

Experimental investigation on fabrication and thermal-stamping of woven jute/polylactic acid biocomposites

2018 ◽  
Vol 53 (7) ◽  
pp. 851-861 ◽  
Author(s):  
Siqi Du ◽  
Xiongqi Peng ◽  
Hailin Gu
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
Alkali Treatment ◽  
Tensile Tests ◽  
Woven Fabrics ◽  
Scanning Calorimetry ◽  
Biodegradable Composites ◽  
One Step ◽  
Jute Fabrics ◽  
Complicated Geometries

Jute woven fabrics in as-received and alkali-treated conditions were respectively combined with polylactic acid resin to fabricate completely biodegradable composites by compression molding in one step. Scanning electron microscopy and differential scanning calorimetry and tensile tests were conducted to estimate the surface morphology, thermal, and mechanical properties of jute fabrics and the composites manufactured. The formability of the composites was evaluated by a thermal-stamping experiment. The results demonstrate that alkali treatment removes the surface impurities of fabrics and refine the fiber structures, lifting the thermal property of composites. As for the mechanical properties, the strength of the fabrics and composites declines while the modulus increases after alkali treatment of fabrics. Although some defects occur, the thermal-stamping experiments confirm the possibility of shaping jute/polylactic acid composite into complicated geometries. And the formability of the composites is influenced by many factors including sample sizes, the holding time of temperature, layup sequence, and so on while the number of layer makes no obvious difference to it.

scholarly journals Reinforcement of Polylactic Acid for Fused Deposition Modeling Process with Nano Particles Treated Bamboo Powder

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1146 ◽  
Author(s):  
Cuicui Wang ◽  
Lee Miller Smith ◽  
Wenfu Zhang ◽  
Mingpeng Li ◽  
Ge Wang ◽  
...  
Keyword(s):  
Polylactic Acid ◽  
Loss Modulus ◽  
Cellulose Nanofibers ◽  
Nano Particles ◽  
Crystalline Cellulose ◽  
Step Method ◽  
Fused Deposition ◽  
One Step ◽  
Bamboo Powder ◽  
The One

The focus of this report was to understand the tensile properties and dynamic mechanical properties of bamboo powder (BP) reinforced polylactic acid (PLA) composite filaments which were treated with nano calcium carbonate (CaCO3), cellulose nanofibers (CNF), and micro-crystalline cellulose (MCC) using impregnation modification technology. The storage modulus (E’) of nano CaCO3-BP/PLA, MCC-BP/PLA, and CNF-BP/PLA composite filaments increased compared with BP/PLA composite filaments before the glass transition temperature Tg. When the temperature was above Tg, the reinforcement effect of nano CaCO3, MCC, and CNF gradually became less apparent. The loss modulus (E’’) and loss factor (tan δmax) of the nano CaCO3-BP/PLA, MCC-BP/PLA, and CNF-BP/PLA composite filaments was higher than that of BP/PLA composite filaments produced by the “one-step” method. The tensile strength (TS) results showed a similar trend. Compared with the control samples, the TS of nano CaCO3-BP/PLA, MCC-BP/PLA, and CNF-BP/PLA composite filaments produced by the “one-step” method (and the “two-step” method) increased by 40.33% (and 10.10%), 32.35% (and −8.61%), and 12.32% (and −12.85%), respectively. The TS of nano CaCO3-BP/PLA, MCC-BP/PLA, and CNF-BP/PLA composite filaments produced by the “one-step” method was slightly higher than those produced by the “two-step” method. The elongation at break (EAB) of BP/PLA composite filaments was higher than that of BP/PLA samples treated with nano CaCO3, MCC, or CNF. The PLA and modified BP were readily accessible through a simple mixing process. The rheological investigation of such mixtures showed that nano CaCO3, CNF, and MCC have different effects on the processability and rheological properties of composites.

An Interactive Minicomputer Program for the Indexing and Simulation of Electron Diffraction Patterns

1976 ◽  
Vol 34 ◽  
pp. 542-543
Author(s):  
R.P. Goehner ◽  
W.T. Hatfield ◽  
Prakash Rao
Keyword(s):  
Electron Diffraction ◽  
Real Time ◽  
Pattern Analysis ◽  
Flow Diagram ◽  
Hard Copy ◽  
Time Analysis ◽  
Real Time Analysis ◽  
Transmission Electron ◽  
One Step ◽  
Diffraction Patterns

Computer programs are now available in various laboratories for the indexing and simulation of transmission electron diffraction patterns. Although these programs address themselves to the solution of various aspects of the indexing and simulation process, the ultimate goal is to perform real time diffraction pattern analysis directly off of the imaging screen of the transmission electron microscope. The program to be described in this paper represents one step prior to real time analysis. It involves the combination of two programs, described in an earlier paper(l), into a single program for use on an interactive basis with a minicomputer. In our case, the minicomputer is an INTERDATA 70 equipped with a Tektronix 4010-1 graphical display terminal and hard copy unit.A simplified flow diagram of the combined program, written in Fortran IV, is shown in Figure 1. It consists of two programs INDEX and TEDP which index and simulate electron diffraction patterns respectively. The user has the option of choosing either the indexing or simulating aspects of the combined program.

Nutrient-regulated gene expression in eukaryotes

2006 ◽  
Vol 73 ◽  
pp. 85-96 ◽  
Author(s):  
Richard J. Reece ◽  
Laila Beynon ◽  
Stacey Holden ◽  
Amanda D. Hughes ◽  
Karine Rébora ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Control ◽  
Direct Interaction ◽  
Signalling Pathways ◽  
A Cell ◽  
One Step ◽  
Higher Eukaryotes ◽  
Regulated Gene Expression

The recognition of changes in environmental conditions, and the ability to adapt to these changes, is essential for the viability of cells. There are numerous well characterized systems by which the presence or absence of an individual metabolite may be recognized by a cell. However, the recognition of a metabolite is just one step in a process that often results in changes in the expression of whole sets of genes required to respond to that metabolite. In higher eukaryotes, the signalling pathway between metabolite recognition and transcriptional control can be complex. Recent evidence from the relatively simple eukaryote yeast suggests that complex signalling pathways may be circumvented through the direct interaction between individual metabolites and regulators of RNA polymerase II-mediated transcription. Biochemical and structural analyses are beginning to unravel these elegant genetic control elements.

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