scholarly journals Superhydrophobic Coating Derived from Geothermal Silica to Enhance Material Durability of Bamboo Using Hexadimethylsilazane (HMDS) and Trimethylchlorosilane (TMCS)

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 530
Author(s):  
Silviana Silviana ◽  
Adi Darmawan ◽  
Febio Dalanta ◽  
Agus Subagio ◽  
Ferry Hermawan ◽  
...  

Bamboo, a fast-growing plant from Asia, is used as building material with unique properties, while exhibiting fast degradation due to its hydrophobicity. Therefore, many attempts have been implemented using several technologies for bamboo modification to alter the hydrophobicity. Most previous studies producing superhydrophobic properties are conducted by using tetraethoxysilane (TEOS) as a precursor agent. However, this method, using TEOS with harmful properties and unaffordable compounds, requires many steps to accomplish the experimental method. Therefore, this paper employed geothermal solid waste as a silica source of the precursor. Thus, an effective and efficient method was applied to prepare superhydrophobic coating by using a precursor of geothermal silica and further modification using hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMCS). The research was executed by the full factorial statistical method using two numerical variables (HMDS/TMCS concentration and silica concentration) and one categorical variable (solvent types). The uncoated material revealed higher weight gain in mass and moisture content than that of the coated bamboo after the soil burial test to assess the durability of the bamboo. However, the durability of superhydrophobic coating realized hydrophobic performance for both agents during sand abrasion for a total of 120 s at an angle of 45°. Statistical results showed the optimum contact angle (CA) achieved in superhydrophobic performance with lower silica concentration for HMDS concentration and the appropriate solvent of n-hexane for HMDS and iso-octane for TMCS. All results were supported using many instruments of analysis to confirm the step-by-step alteration of geothermal silica to be used as a superhydrophobic coating, such as XRF, XRD, FTIR, SEM, and SEM EDX.

Author(s):  
Aurélie Van Wylick ◽  
Elise Elsacker ◽  
Li Li Yap ◽  
Eveline Peeters ◽  
Lars de Laet

In the search for environmentally friendly materials, mycelium composites have been labelled as high potential bio-based alternatives to fossil-based and synthetic materials in various fields. Mycelium-based materials are praised for their biodegradability, however no scientific research nor standard protocols exist to substantiate this claim. This research therefore aims to develop an appropriate experimental methodology as well as to deliver a novel proof of concept of the material’s biodegradability. The applied methodology was adapted from a soil burial test under predefined laboratory conditions and hands-on preliminary experiments. The mycelium composite samples were placed in a nylon netting and then buried in potting soil with a grain size of 2 mm for different time-intervals ranging between one and sixteen weeks. Results showed that mycelium, which acted as the binder, had the tendency to decompose first. A weight loss of 43% was witnessed for inert samples made of the fungal strain Ganoderma resinaceum and hemp fibres after sixteen weeks. The disintegration rate in this method however depended on various parameters which were related to the material’s composition, its production method and the degradation process which involved the used equipment, materials and environmental properties.


2005 ◽  
Vol 96 (4) ◽  
pp. 1064-1071 ◽  
Author(s):  
Eun-Soo Park ◽  
Hun-Sik Kim ◽  
Mal-Nam Kim ◽  
Jin-San Yoon

Horticulturae ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 47
Author(s):  
Huan Zhang ◽  
Markus Flury ◽  
Carol Miles ◽  
Hang Liu ◽  
Lisa DeVetter

Soil-biodegradable plastic mulches (BDMs) are made from biodegradable materials that can be bio-based, synthetic, or a blend of these two types of polymers, which are designed to degrade in soil through microbial activities. The purpose of BDMs is to reduce agricultural plastic waste by replacing polyethylene (PE) mulch, which is not biodegradable. Most studies have evaluated the breakdown of BDMs within annual production systems, but knowledge of BDM breakdown in perennial systems is limited. The objective of this study was to evaluate the deterioration and degradation of BDMs in a commercial red raspberry (Rubus ideaus L.) production system. Deterioration was low (≤11% percent soil exposure; PSE) for all mulches until October 2017 (five months after transplanting, MAT). By March 2018 (10 MAT), deterioration reached 91% for BDMs but remained low for PE mulch (4%). Mechanical strength also was lower for BDMs than PE mulch. In a soil burial test in the raspberry field, 91% of the BDM area remained after 18 months. In-soil BDM degradation was minimal, although the PSE was high. Since mulch is only applied once in a perennial crop production system, and the lifespan of the planting may be three or more years, it is worth exploring the long-term degradation of BDMs in perennial cropping systems across diverse environments.


2003 ◽  
Vol 11 (3) ◽  
pp. 219-227 ◽  
Author(s):  
Chris Kneale

Many factors need to be considered in the design of new biocides for use in plastics applications. In Europe, biocides are now becoming more tightly regulated under the Biocidal Products Directive (BPD), and a significant data package needs to be provided not only for the registration of new actives, but also for existing biocides and biocidal formulations. A novel biocide must be compatible with the polymer matrix and must not adversely affect its physical properties. Once the issue of compatibility has been overcome, the antimicrobial efficacy of the biocide in the substrate should be established. Before selecting a test method to demonstrate such efficacy, it is necessary to consider whether the substrate should be pre-conditioned to simulate end use conditions, e.g. by leaching or artificial weathering. The final use of the product can also dictate the test protocol, e.g. a building membrane for ground contact should be evaluated using a soil burial test. Historically, biocides have been added to plastics to prevent their spoilage by fungal attack. Latterly, plastics with antibacterial effects have aroused much public interest. Advantages and disadvantages of traditional test methods will be discussed, and an alternative method for the evaluation of biocidal performance that is thought to be more representative of end use conditions will be presented.


2016 ◽  
Vol 846 ◽  
pp. 673-678 ◽  
Author(s):  
Nurul Aina Ismail ◽  
Syuhada Mohd Tahir ◽  
Yahya Norihan ◽  
Muhamad Firdaus Abdul Wahid ◽  
Nur Ezzati Khairuddin ◽  
...  

This study was carried out to evaluate the potential of plastic synthesized using bio-based starch. The method began with extraction of starch from chosen tubers with high content of starch; potato and yam. The samples were first grated, grinded and strained to obtain crude starch, which then centrifuged and rinsed to get pure starch. The starch was then reacted with hydrochloric acid to breakdown amylopectin to prevent the starch from becoming plastic-like. Finally, propan-1,2,3-triol was added as a plasticizer to increase the elasticity of the product. The chemical, mechanical, and thermal properties of the products were analyzed using Fourier transform infrared (FTIR), tensile strength tester and Thermogravimetric analysis (TGA). The FTIR spectra of the product displayed the presence of O-H, C-H, C=O and C-O absorption peaks, which indicate the formation of bioplastic has already occured. The tensile strength obtained for potato and yam starch-based bioplastic are 0.6 MPa and 1.9 MPa, respectively. The result gained from TGA showed that 50% weight loss occurred at 250°C for potato and 310°C for yam-based plastic. The highly biodegradability of the plastic was proven using soil burial test, which observed the percentage of soil biodegradation for potato and yam-based bioplastic in 1 week duration is 43% and 26%, respectively. These bio-based plastics have exhibited good thermal and mechanical properties with high biodegradability that makes them a suitable alternative for the existing conventional plastics.


Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3399 ◽  
Author(s):  
Domen Malis ◽  
Barbka Jeršek ◽  
Brigita Tomšič ◽  
Danaja Štular ◽  
Barbara Golja ◽  
...  

This research aimed to study the influence of lyocell with incorporated ZnO (CLY) for antibacterial activity and biodegradation of fiber blends composed of viscose (CV), flax (LI), and CLY. Fiber blended samples with an increased weight fraction of CLY fibers were composed, and single CLY, CV and LI fibers were also used for comparison. Antibacterial activity was determined for the Gram-negative Escherichia coli and the Gram-positive Staphylococcus aureus bacteria. The biodegradation of fiber blends was investigated by the soil burial test. The results show that the single CLY fibers exhibited high antimicrobial activity against both E. coli and S. aureus bacteria and that the presence of LI fibers in the blended samples did not significantly affect antibacterial activity against E. coli, but drastically decreased the antibacterial activity against S. aureus. LI fibers strongly promoted the growth of S. aureus and, consequently, impaired the antimicrobial performance of ZnO against this bacterium. The presence of CLY fibers slowed down, but did not prevent, the biodegradation process of the fiber blends, even at the highest ZnO concentration. The soil that was in contact with the fiber blended samples during their burial was not contaminated to such an extent as to affect the growth of sprouts, confirming the sustainability of the fiber blends.


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