The Study of Chitosan Solution Coating on Water Barrier Property of Seedling Paper Bag Made from Water Hyacinth

2021 ◽  
Vol 1047 ◽  
pp. 97-102
Author(s):  
Nattanicha Khamsao ◽  
Kornkamon Waengwan ◽  
Sunisorn Konchai ◽  
Poonnapat Patthong ◽  
Bpantamars Phadungchob ◽  
...  

Seedling bags are low cost and light weight containers used by farmers to germinate and sprout seeds into seedlings before transplanting into the ground. However, cutting and removing seedling bags before the transplantation can damage the plant roots and cause losses in their productivity. In addition, plastics used in conventional seedling bags contribute to more plastic waste during this process. This study offers a solution to these problems with alternative biodegradable materials; i.e. modified papers made from an invasive alien aquatic plant species—water hyacinth—and enhanced with Chitosan solution coating. Papers were made from water hyacinth and dipped or sprayed with Chitosan solution in acetic acid at concentrations of 1% wt., 1.5% wt., and 2% wt. The dipping method showed better water barrier properties than the spraying method in every concentration, with 2% wt. concentration having the best barrier properties. The 2% wt. concentration of Chitosan coating by dipping method changed the water contact angle of the water hyacinth paper from a hydrophilic to a hydrophobic surface. This enhancement in water resistance was confirmed by water absorption time, which reached over 1.5 hours—3 times longer than the spraying method.

2020 ◽  
Vol 1015 ◽  
pp. 89-93
Author(s):  
Thitipong Wutisart

Paper made from water hyacinth which was modified by PLA solvent coating and the PLA content were varied for finding the most appropriate content. The SEM images of both surface and cross section were carried out for showing the interaction between the water hyacinth paper and PLA film. The water barrier properties of PLA content at 0.4 % (W/V) and 0.6 % (W/V) showed the hydrophobic properties of water hyacinth paper. The modified water hyacinth paper could resist water being indicated by water absorption which was over 90 minute/5µL in any PLA content.


Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2234
Author(s):  
Carmela T. Prontera ◽  
Giuliano Sico ◽  
Maria Montanino ◽  
Anna De Girolamo Del Mauro ◽  
Paolo Tassini ◽  
...  

Zinc oxide nanoparticles (ZnONPs) and stearic acid are herein used for the preparation of hydrophobic coatings with good moisture barrier property on flexible plastic substrates. Fast, high throughput, mild and easy-to-run processing techniques, like airbrushing and gravure printing, are applied for thin films deposition of these materials. The results of this study indicated that the best hydrophobic coating in terms of water contact angle (115°) is obtained through a two-steps printing deposition of a ZnONPs layer followed by a stearic acid layer. All the deposition procedures proved to be effective in terms of water vapor barrier properties, reaching values of 0.89 g/m2/day, with a 45% reduction with respect to the bare substrate. These preliminary data are very encouraging in the perspective of a low cost and green approach for the realization of functional coatings for packaging applications.


Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1757 ◽  
Author(s):  
Rui Yang ◽  
Yunyi Liang ◽  
Shu Hong ◽  
Shida Zuo ◽  
Yingji Wu ◽  
...  

As a hydrophilic material, wood is difficult to utilize for external applications due to the variable weather conditions. In this study, an efficient, facile, and low-cost method was developed to enhance the hydrophobicity of wood. By applying the low-temperature chemical vapor deposition (CVD) technology, the polydimethylsiloxane-coated wood (PDMS@wood) with hydrophobic surface was fabricated employing dichlorodimethylsilane as the CVD chemical resource. The result of water contact angle (i.e., 157.3°) revealed the hydrophobic behavior of the PDMS@wood. The microstructures of the wood samples were observed by scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS) analysis verified PDMS successfully coated on wood surfaces. The chemical functional groups of the PDMS@wood were investigated by Fourier transform infrared (FT-IR) and Raman spectra. The thermogravimetric results indicated the enhanced thermal stability of the wood after PDMS coating. In addition, the stability test of PDMS@wood indicated that the hydrophobicity properties of the PDMS@wood samples were preserved after long-time storage (e.g., 30 days). The scratch test was carried out to examine the abrasion resistance of the hydrophobic coatings on PDMS@wood surface. It was suggested that low-temperature CVD process could be a successful approach for fabricating hydrophobic wood.


Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 331
Author(s):  
Pornchai Rachtanapun ◽  
Sarinthip Thanakkasaranee ◽  
Rafael A. Auras ◽  
Nareekan Chaiwong ◽  
Kittisak Jantanasakulwong ◽  
...  

Carboxymethyl rice starch films were prepared from carboxymethyl rice starch (CMSr) treated with sodium hydroxide (NaOH) at 10–50% w/v. The objective of this research was to determine the effect of NaOH concentrations on morphology, mechanical properties, and water barrier properties of the CMSr films. The degree of substitution (DS) and morphology of native rice starch and CMSr powders were examined. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) were used to investigate the chemical structure, crystallinity, and thermal properties of the CMSr films. As the NaOH concentrations increased, the DS of CMSr powders increased, which affected the morphology of CMSr powders; a polyhedral shape of the native rice starch was deformed. In addition, the increase in NaOH concentrations of the synthesis of CMSr resulted in an increase in water solubility, elongation at break, and water vapor permeability (WVP) of CMSr films. On the other hand, the water contact angle, melting temperature, and the tensile strength of the CMSr films decreased with increasing NaOH concentrations. However, the tensile strength of the CMSr films was relatively low. Therefore, such a property needs to be improved and the application of the developed films should be investigated in the future work.


1991 ◽  
Vol 23 (7-9) ◽  
pp. 1503-1507 ◽  
Author(s):  
L. M. Triet ◽  
N. T. Viet ◽  
T. V. Thinh ◽  
H. D. Cuong ◽  
J. C. L. van Buuren

The effluent from activated sludge treatment of petroleum wastewater was treated with the aid of a ponding system using aquatic plants (Water Hyacinth, Chlorella, Reed). A good result was obtained in this study. Pilot pond system shows that the purification efficiency depends on the residence time of about 14 days. The petroleum removal waa 97-98 %, the COD removal was from 88-93 %. The dissolved oxygen amount (with Chlorella) increased from 0.7 mg/l to 9.8 mg/l and the pH increased from 6.9 to 8-8.6. The application of 3 step biological pond with the use of Water Hyacinth, Chlorella, Reeds for post treatment of petroleum wastewater is appropriate in Vietnam.


2020 ◽  
Vol 23 (7) ◽  
pp. 587-598 ◽  
Author(s):  
Ahmed Refaat ◽  
Hanan Elhaes ◽  
Nabila S. Ammar ◽  
Hanan S. Ibrahim ◽  
Medhat Ibrahim

Aim and Objective: Wastewater treatment/remediation is a very important process that has a great environmental and economic impact. Therefore, it is crucial to innovate different methods to remove pollutants of different sources from wastewater. This work was conducted in order to study the removal of lead (Pb+2) from wastewater using microspheres of composites of sodium alginate, cellulose and chitosan, as well as using a cost-effective green route through composites of sodium alginate and dried water hyacinth. Materials and Methods: Molecular modeling at B3LYP/6-31g(d,p) was utilized to study sodium alginate, cellulose and chitosan. Sodium alginate was cross-linked with calcium chloride to form microspheres, then both sodium alginate/cellulose and sodium alginate/chitosan were also crosslinked as 50/50 to form microspheres. The roots of the aquatic plant water hyacinth in dry form were added to the cross-linked sodium alginate for up to 70%. SEM and FTIR were employed to study the surface of the prepared microspheres and their structures respectively. Atomic absorption spectroscopy was used to study the levels of Pb. Results: Molecular modeling indicated that the blending of such structures enhances their ability to bind with surrounding molecules owing to their ability to form hydrogen bonds. SEM results indicated that homogeneous structures of cellulose and chitosan are deformed when blended with sodium alginate, and FTIR confirmed the proper formation of the desired blends. Microspheres from sodium alginate showed the ability to remove Pb+2 from wastewater. SEM indicated further deformation in the morphology with the roughness of sodium alginate/water hyacinth microspheres, while FTIR confirmed the uniform matrices of the microspheres. The removal of Pb+2 was enhanced because of the addition of dried water hyacinth's roots. Conclusion: Modeling, experimental and kinetic data highlight sodium alginate/water hyacinth root as a green route to remediate Pb+2 from wastewater.


2021 ◽  
Vol 13 (15) ◽  
pp. 8244
Author(s):  
Francesca Cirisano ◽  
Michele Ferrari

Highly hydrophobic and superhydrophobic materials obtained from recycled polymers represent an interesting challenge to recycle and reuse advanced performance materials after their first life. In this article, we present a simple and low-cost method to fabricate a superhydrophobic surface by employing polytetrafluoroethylene (PTFE) powder in polystyrene (PS) dispersion. With respect to the literature, the superhydrophobic surface (SHS) was prepared by utilizing a spray- coating technique at room temperature, a glass substrate without any further modification or thermal treatment, and which can be applied onto a large area and on to any type of material with some degree of fine control over the wettability properties. The prepared surface showed superhydrophobic behavior with a water contact angle (CA) of 170°; furthermore, the coating was characterized with different techniques, such as a 3D confocal profilometer, to measure the average roughness of the coating, and scanning electron microscopy (SEM) to characterize the surface morphology. In addition, the durability of SH coating was investigated by a long-water impact test (raining test), thermal treatment at high temperature, an abrasion test, and in acidic and alkaline environments. The present study may suggest an easy and scalable method to produce SHS PS/PTFE films that may find implementation in various fields.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 251
Author(s):  
Jijia Zhang ◽  
Jihu Wang ◽  
Shaoguo Wen ◽  
Siwei Li ◽  
Yabo Chen ◽  
...  

In this paper, an environmentally friendly waterborne polyurea (WPUA) emulsion and its corresponding coating were prepared, which was characterized by dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM). To improve the performance of the coating, we doped sulfonated graphene (SG) into WPUA to prepare composite coating (SG/WPUA). SG can be uniformly dispersed in WPUA emulsion and is stable for a long time (28 days) without delamination. The water resistance of the composite coating with 0.3 wt.% SG nanofiller was improved; the water contact angle (WCA) result was SG/WPUA (89°) > WPUA (48.5°), and water absorption result was SG/WPUA (2.90%) < WPUA (9.98%). After water immersion treatment, SEM observation revealed that the SG/WPUA film only generated enlarged microcracks (100 nm) instead of holes (150–400 nm, WPUA film). Polarization curves and electrochemical impedance spectroscopy (EIS) tests show that SG nanosheets with low doping content (0.3 wt.%) are more conducive to the corrosion resistance of WPUA coatings, and the model was established to explain the mechanism.


Author(s):  
Bruna Rage Baldone Lara ◽  
Paulo Sérgio de Andrade ◽  
Mario Guimarães Junior ◽  
Marali Vilela Dias ◽  
Lizzy Ayra Pereira Alcântara

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 646
Author(s):  
Victor Gomes Lauriano Souza ◽  
Marta M. Alves ◽  
Catarina F. Santos ◽  
Isabel A. C. Ribeiro ◽  
Carolina Rodrigues ◽  
...  

This work aimed to produce bionanocomposites of chitosan incorporated with zinc oxide nanoparticles (ZnO NPs) synthesized using food industry by-products and to characterize them. Such nanoparticles are highlighted due to their low cost, antimicrobial activity, accessibility, and sustainability synthesis. Four different levels of ZnO NPs (0, 0.5, 1.0, and 2.0% w/w of chitosan) were tested, and the bionanocomposites were characterized in terms of their hydrophobicity, mechanical, optical, and barrier properties. Overall, the incorporation of ZnO NPs changed the composites from brittle to ductile, with enhanced elongation at break and reduced Young Modulus and tensile strength. Thus, ZnO NPs acted as plasticizer, turning the films more flexible, due to the presence of organic compounds on the NPs. This also favored permeability of oxygen and of water vapor, but the good barrier properties were maintained. Optical properties did not change statistically with the ZnO NPs incorporation. Thus, the characterization presented in this paper may contribute to support a decision on the choice of the material’s final application.


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