Comparison of morphological, structural and antibacterial properties of different Apocynum venetum poly (lactic acid)/nanocellulose nanofiber films

2019 ◽  
Vol 90 (5-6) ◽  
pp. 593-605 ◽  
Author(s):  
Lu Wang ◽  
Chenmeizi Wang ◽  
Qingle Zhang ◽  
Jianhua Liu ◽  
Xin Xia
Keyword(s):  
Lactic Acid ◽  
Cellulose Nanofibers ◽  
Antibacterial Properties ◽  
Poly Lactic Acid ◽  
Water Contact ◽  
Environment Friendly ◽  
Hydrolysis Method ◽  
Apocynum Venetum ◽  
Novel Material ◽  
Cnf Films

As new bio-based sustainable materials, this paper made a comparative study on the phloem and straw of Apocynum venetum. The cellulose nanofibers (CNFs) of Apocynum venetum phloem and straw were prepared by the acid hydrolysis method, and then different parts and proportions of poly (lactic acid) (PLA)/CNF films were prepared via electrospinning, respectively. The results revealed the CNF with longer length and finer diameter network structure can be separated by straw, while the short nanostructure of the rod-like structure can be separated by phloem. It was also shown that the wettability and permeability of PLA improved significantly by adding these two kinds of CNFs, the water contact angle of PLA decreased from 130° to 101° and the permeability was up to 4658 g/(m2•d). As for antibacterial properties, the antibacterial rate of CNF from straw proved slightly better than that from phloem against E.coli, reaching more than 90%. It proved that the CNF from straw showed excellent performance as phloem, providing a novel material for the preparation of CNFs, which can be naturally antibacterial and environment-friendly. The obtained PLA/CNF films could be potentially applied in antibacterial medical dressings.

Biocomposites of Poly(Lactic Acid) and Cellulose Nanofibers from Cassava Pulp

2017 ◽  
Vol 753 ◽  
pp. 13-17
Author(s):  
Chi Nguyen Thanh ◽  
Ruksakulpiwat Chaiwat ◽  
Ruksakulpiwat Yupaporn
Keyword(s):  
Electron Microscopy ◽  
Lactic Acid ◽  
Impact Strength ◽  
Epoxy Group ◽  
Cellulose Nanofibers ◽  
Poly Lactic Acid ◽  
Melt Mixing ◽  
Hydrolysis Method ◽  
Cassava Pulp ◽  
The Impact

Cellulose nanofibers (CNFs) were used as biobased fillers to prepare poly(lactic acid) (PLA)-based biocomposites. Cellulose nanofibers were extracted from cassava pulp (CP) by acid hydrolysis method. Before submitted to acid treatment, CP was pre-treated by alkali and bleaching treatments. The biocomposites were prepared by melt mixing, followed by hot melt pressing. In order to improve the compatibility of CNFs with PLA matrix, glycidyl methacrylate (GMA) grafted poly (lactic acid) (PLA-g-GMA) was used as a compatibilizer. PLA-g-GMA was prepared by grafting of GMA onto PLA chain via melt mixing using an internal mixer. Transmission electron microscopy (TEM) micrograph shows that most nanofibers with the diameter in the range of 10-30 nm and immeasurable length were obtained. The appearance of two new peaks at 49.07 and 44.71 ppm in the carbon-13 nuclear magnetic resonance (13C-NMR) spectrum of PLA-g-GMA, which represent the carbons of the epoxy group of GMA, confirms that GMA was successfully grafted onto PLA chain. The morphology of biocomposites, characterized by scanning electron microscopy (SEM), reveals that without using PLA-g-GMA, the poor dispersion of CNFs in PLA matrix was observed. In contrast to that, with using PLA-g-GMA, the dispersion of CNFs in PLA matrix was improved. Moreover, the impact strength results show that by incorporating 1.0 wt% CNFs into PLA matrix and using PLA-g-GMA as a compatibilizer, the impact strength of biocomposites was slightly enhanced compared to that of pure PLA.

Biodegradable Microfluidic Device: Hydrolysis, Decomposition and Surface Modification

2010 ◽  
Vol 447-448 ◽  
pp. 755-759 ◽  
Author(s):  
Jia En Low ◽  
Wei Xiang Koh ◽  
Joon Kit Lai ◽  
Yan Jie Lee ◽  
Xu Li ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Microfluidic Device ◽  
Ph Value ◽  
Blood Compatibility ◽  
Blood Clot ◽  
Hydrophobic Surface ◽  
Poly Lactic Acid ◽  
Water Contact ◽  
Chemical Grafting ◽  
Poly Ethylene

Poly(lactic acid) (PLA) is a biodegradable and biocompatible aliphatic polyester whose lactic acid monomers are derived from renewable resources such as corn and sugar beet. As a thermal plastic it can be processed through compounding and injection. As such, we have developed a microfludic device using PLA aimed at blood dialysis application. To quantify the degradation of PLA, its hydrolysis at different pH value was studied. To study the bioresorbable property of these fabricated devices, its decomposition was tested by morphology observation and weight change measurements after embedding in soil under simulated environmental conditions. Upon contact with a hydrophobic surface, platelets and prothrombin are always activated to attach to the surface, resulting in blood clot. This would block the blood flow through the dialysis channels in the microfluidic device. To improve the hydrophilicity, hence the blood compatibility, chemical grafting of a hydrophilic polymer, poly(ethylene oxide) methacrylate (PEGmA), onto the surface of PLA microfluidic device was carried out and the changes in hydrophilicity was monitored through measuring the water contact angle. Our results indicate that chemical grafting of PEGmA significantly improves the hydrophilicity of the device surface.

Effect of cellulose nanofibers from cassava pulp on physical properties of poly(lactic acid) biocomposites

2019 ◽  
Vol 33 (8) ◽  
pp. 1094-1108
Author(s):  
Thanh Chi Nguyen ◽  
Chaiwat Ruksakulpiwat ◽  
Yupaporn Ruksakulpiwat
Keyword(s):  
Lactic Acid ◽  
Cellulose Nanofibers ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Melt Mixing ◽  
Cassava Pulp ◽  
Lower Temperature ◽  
Alkali Hydrolysis ◽  
Internal Mixer

Biocomposites of poly(lactic acid) (PLA) and cellulose nanofibers (CNFs) extracted from cassava pulp were successfully prepared by melt mixing in an internal mixer. CNFs were prepared from cassava pulp by submitting to alkali hydrolysis, bleaching treatment, and acid hydrolysis. The compatibility between CNFs and PLA matrix was improved using glycidyl methacrylate (GMA) grafted PLA (PLA-g-GMA) as an effective compatibilizer. Higher elongation at break and impact strength of PLA/PLA-g-GMA/CNFs biocomposites was achieved compared to that of neat PLA. PLA-g-GMA shows a strong effect on the crystallization behavior of the biocomposites. The PLA/PLA-g-GMA/CNFs biocomposites induce cold crystallization to take place at lower temperature. Higher degree of crystallinity of PLA/PLA-g-GMA/CNFs biocomposites was obtained compared to PLA/CNFs biocomposites. The mechanical and thermal properties of PLA/CNFs biocomposites at various ratios were investigated. With increasing CNFs contents, the modulus of the biocomposites increases. Thermal stability of PLA/CNFs and PLA/PLA-g-GMA/CNFs biocomposites did not change significantly compared to that of neat PLA.

Chemo-enzymatic preparation and characterization of cellulose nanofibers-graft-poly(lactic acid)s

2019 ◽  
Vol 114 ◽  
pp. 308-318 ◽  
Author(s):  
Chaniga Chuensangjun ◽  
Takuya Kitaoka ◽  
Yusuf Chisti ◽  
Sarote Sirisansaneeyakul
Keyword(s):  
Lactic Acid ◽  
Cellulose Nanofibers ◽  
Poly Lactic Acid ◽  
Enzymatic Preparation

Surface-Modified Cellulose Nanofibers-graft-poly(lactic acid)s Made by Ring-Opening Polymerization of l-Lactide

2019 ◽  
Vol 27 (4) ◽  
pp. 847-861 ◽  
Author(s):  
Chaniga Chuensangjun ◽  
Kyohei Kanomata ◽  
Takuya Kitaoka ◽  
Yusuf Chisti ◽  
Sarote Sirisansaneeyakul
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Cellulose Nanofibers ◽  
Ring Opening Polymerization ◽  
Poly Lactic Acid ◽  
Surface Modified ◽  
Modified Cellulose

Surface Engineered Poly(lactic acid) (PLA) Microspheres by Chemical Treatment for Drug Delivery System

2013 ◽  
Vol 594-595 ◽  
pp. 214-218 ◽  
Author(s):  
C.Y. Tham ◽  
Zuratul Ain Abdul Hamid ◽  
Z.A. Ahmad ◽  
H. Ismail
Keyword(s):  
Drug Delivery ◽  
Contact Angle ◽  
Lactic Acid ◽  
Drug Delivery System ◽  
Water Contact Angle ◽  
Delivery System ◽  
Alkaline Solution ◽  
Alkaline Hydrolysis ◽  
Poly Lactic Acid ◽  
Water Contact

Poly (lactic acid) (PLA) is well known for their biodegradability and bioresorbable properties and these properties made them suitable in drug delivery system as drug carriers. PLA is relatively hydrophobic and lack of cell-recognition group to interact with biologically active molecules which reduce the surface compatibility of microspheres. In this project, alkaline hydrolysis was used to induce hydrophilic functional group on the microspheres surface. Alkaline solution at 0.01M and 0.1M was used to modify microspheres surfaces. The engineered surfaces were evaluated using Scanning Electron Microscopy and Water Contact Angle. 0.1M alkaline solution hydrolyzed microspheres at higher extends as compared to 0.01M, where partial microspheres disintegrated and porous structure was revealed. The water contact angle of PLA films shows decreased from 65 ̊ to range 42 47 ̊ after alkaline hydrolysis.

Crystallization behavior studied by synchrotron small-angle X-ray scattering of poly (lactic acid)/cellulose nanofibers composites

2017 ◽  
Vol 143 ◽  
pp. 106-115 ◽  
Author(s):  
Thanh Chi Nguyen ◽  
Chaiwat Ruksakulpiwat ◽  
Supagorn Rugmai ◽  
Siriwat Soontaranon ◽  
Yupaporn Ruksakulpiwat
Keyword(s):  
Lactic Acid ◽  
Small Angle ◽  
Crystallization Behavior ◽  
Cellulose Nanofibers ◽  
Poly Lactic Acid ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Bio-Composites Consisting of Cellulose Nanofibers and Na+ Montmorillonite Clay: Morphology and Performance Property

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1448 ◽  
Author(s):  
Runzhou Huang ◽  
Xian Zhang ◽  
Huiyuan Li ◽  
Dingguo Zhou ◽  
Qinglin Wu
Keyword(s):  
Cellulose Nanofibers ◽  
Composite Films ◽  
Performance Property ◽  
Water Contact ◽  
Third Stage ◽  
Networking Ability ◽  
Apparent Activation Energies ◽  
And Performance ◽  
Cnf Films ◽  
Degradation Properties

This paper reports the usage of cellulose nanofibers (CNFs) as a continuous nanoporous matrix and nanoclay (NC) as additive to fabricate hybrid films. CNF/Cloisite Na+ nanoclay composite films containing 10–50 wt % of NC were prepared for the study. The effects of NC incorporation and its content on mechanical, wettability and thermal degradation properties were investigated. The results showed that the film had a multilayer structure with gradually deposited CNT-NC hybrid on the filter paper Pure CNF films had higher moduli compared with those from the composite films, as the incorporation of NC decreased hydrogen bonding and networking ability of CNFs, especially at the high NC loading levels. The composite films demonstrated self-extinguishing ability when being exposed to the open flame. Composites with over 35 wt % NC did not burn because of the formation of a protective barrier containing ordered NC platelets. The addition of montmorillonite NC led to increased surface water contact angle, showing enhanced hydrophobicity of the material. During the film’s thermal pyrolysis, the first process occurred between 100 and 200 °C, resulting mainly from the evaporation of absorbed water; the second, between 280 and 350 °C, indicated thermal decomposition of cellulose; and the slow third stage happened from the 350 to 600 °C, representing carbonization. The results demonstrate that the apparent activation energies for all the CNF/NC composites were higher than the pure CNF film. CNF/NC films fabricated in this process are a promising barrier material for packaging applications.

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