• Journal of the Korea Institute of Building Construction
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• v.5 no.2 s.16
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• pp.97-105
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• 2005

Concrete structures in the marine environment often deteriorate in the early stage of their service life because of contact with various aggressive conditions. In recent years, the researches on the concrete in the marine environment have been carried out to increase their service life. In this experimental study, the concrete specimens were prepared with various adding contents of inorganic antifouling agent$(0\~3.0wt\%)$ composed of some fluosilicate solution. For evaluation of the properties of concretes containing inorganic antifouling agent, various tests such as setting time, slump loss, compressive strength, water absorption rate, fleering and thawing resistance and SEM of concrete, were conducted. As the results, physical and chemical properties of concretes were improved with an adding of inorganic antifouling agent. From the results of various tests, the optimal adding contents of antifouling agent was $1.0wt\%$.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.604-607
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• 2004

Concrete structures in the marine environment often deteriorate in the early stage of their service life because of contact with various aggressive conditions. In recent years, the study on the concrete in the marine environment are carried out to increase their service life. In this experimental study, the concrete specimens were prepared with various adding contents of inorganic antifouling agent$(0\~3.0wt\%)$ composed to some fluosilicate solution. For evaluatin of the physical and chemical properties of concretes containing inorganic antifouling agent, various tests such as setting time, slump loss, compressive strength, water absorption rate, freezing and thawing resistance and SEM micrographs of concrete, were conducted. As the results, physical and chemical properties of concretes were improved with an adding of inorganic antifouling agent. From the results of various tests, the optimal adding contents of antifouling agent was $1.0wt\%$.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.5
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• pp.1-8
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• 2023

Marine and hydraulic structures are subject to durability damage not only due to the penetration of sea water but also due to the attachment of marine organisms. Therefore, in this study, we tried to develop an antifouling coating agent with self-cleaning function for marine concrete. It was confirmed that the antifouling coating agent mixed with AKD, cellulose nanofibers and BADGE had sufficient antifouling performance at a well hydrophobicity of around 140° in contact angle and an inclination angle of 15°. In the abrasion resistance test of the surface, only a maximum loss of 0.015 g occurred. In the durability test, as a result of the chloride ion permeation test, almost no chloride ion permeation occurred in the variable where the coating agent was applied, and carbonation and freeze-thaw damage also rarely occurred, so it was analyzed that it was effective in securing durability of concrete.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.2
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• pp.85-93
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• 2012

We study on the distribution characteristics of antifouling agents such as Sea-nine 211, Irgarol 1051, Diuron using HS-SPME method in southwestern coast of Korea. Short half-life of Sea-nine 211 was distributed in very low concentrations and/or below detection limits in all of the sampling points, both water and sediments samples. Irgarol 1051 was detected to have the highest concentration respectively $6.98{\mu}g/L$, 28.50 ng/g-dry wt in the seawater and sediments, and regional distribution characteristics did not appeared. Strong bioaccumulation and long half-life of Diuron was distributed higher concentration than in all sampling point and was analyzed to have the highest concentration(3882.22 ng/g-dry wt) Mo7(Mokpo)'s sediment. Irgarol 1051 and Diuron distributed in the shipbuilding industry and ship marina are located just at the point to found in high concentrations. In addition, the distribution of the antifouling agent materials were lower in concentration than in inner bay to outter bay in sediments. Antifouling agent materials from these results were contaminated high potential from port and shipbuilding industry located in inner bay.

• Journal of the Korean Applied Science and Technology
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• v.34 no.1
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• pp.152-162
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• 2017

A hydrophilic coating solution was prepared by adding a silane coupling agent and a nano-inorganic oxide in aqueous surfactant solution to increase the efficiency of photovoltaic power generation due to the introduction of antifogging and antifouling properties on the glass surface of the solar cell module. Addition of $Ludox^{(R)}$, a nano-inorganic oxide, to 1% hydrophilic coating solution showed improved hydrophilicity and excellent antifogging effect regardless of $Ludox^{(R)}$ concentration. However, the antifouling effect on the glass surface was showed only when Ludox was added more than 10%. In the case of addition of 0.7% of hydrolyzed TEOS at pH 4, the antifogging effect was maintained as a result of the steam test as well as the antifouling effect even after the coated glass surface was rubbed 100 times with a wet Kimwipe. In addition, from the surface roughness ($R_q$) calculated using AFM data, the higher surface roughness with irregular surface shape was obtained with the higher concentration of TEOS. The addition of 0.7% of TEOS showed relatively high surface roughness and well organized surface condition which can help to improve transmittance of light. In conclusion, $Ludox^{(R)}$ is not required only for the antifogging property. However, at least 10% of Ludox should be added to show antifouling effect and 0.7% of TEOS should be added for good durability.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.1
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• pp.21-28
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• 2006

Since the usage of tributyltin(TBT) has been banned, many chemicals including Sea-Nine 211, Cu-pyrithione, and Zn-pyrithione were developed to use as antifouling agents for ships and coastal structures. However, the toxicity of these antifouling chemicals have not been systematically evaluated in ecotoxicological and biological studies. In this study, we investigated the effect of four antifouling substances on survival of estuarine rockfish, Sebastes schlegeli and amphipod, Monocorophium acherusicum. Survival of S. schlegeli and M. acherusicum during the 96-h exposure period were used to estimate the median lethal concentrations(LC50s) of test chemicals for each test species. Among antifouling agents, Cu-pyrithione($56{\mu}g{\cdot}1^{-1}$;96-h LC50) was most toxic to S. schlegeli, followed by $TBT(73{\mu}g{\cdot}1^{-1}),\;Sea-Nine(184{\mu}g{\cdot}1^{-1})\;and\;Zn-pyrithione(l707{\mu}g{\cdot}1^{-1})$, while TBT($26{\mu}g{\cdot}1^{-1}$) was most toxic to M. acherusicum followed by Sea-Nine($49{\mu}g{\cdot}1^{-1}$), Cu-pyrithione($119{\mu}g{\cdot}1^{-1}$) and Zn-pyrithione($334{\mu}g{\cdot}1^{-1}$). Effect concentrations of the antifouling chemicals estimated in this study can be used when assessing the potential risks of these substances, of which usage is increasing in the coastal environment.

• Korean Journal of Environmental Biology
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• v.36 no.3
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• pp.392-399
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• 2018

Toxicity assessment of antifouling agent, zinc undecylenate (ZU) has been investigated using the rate of survival and population growth in marine rotifer, Brachionus plicatilis. The survival rate of Brachionus plicatilis was determined after 24 h of exposure to ZU and was not affected up to the maximum level of $100.0mg\;L^{-1}$ of ZU. The population growth rate (r) was determined after 72 h of exposure to ZU. It was observed that r in the controls (absence ZU) was greater than 0.5 but exhibited a sudden decrease with an increase in the concentration of ZU. ZU reduced r in a dose-dependent manner and a significant reduction occurred at a concentration greater than $12.5mg\;L^{-1}$. The 50% effective concentration ($EC_{50}$) value of r during ZU exposure was $26.4mg\;L^{-1}$, No-observed-effect-concentration (NOEC) was $6.3mg\;L^{-1}$ and Lowest-observed-effect-concentration (LOEC) was $12.5mg\;L^{-1}$, respectively. Based on the results, it is apparent that ZU concentration greater than $12.5mg\;L^{-1}$ exhibited a toxic effect on the r of zooplankton, B. plicatilis in natural ecosystems.

• Membrane and Water Treatment
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• v.3 no.1
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• pp.35-49
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• 2012

In membrane processes, various agents are used to enhance, protect, and recover membrane performance. Applying these agents in membrane modification could potentially be considered as a simple method to improve membrane performance without additional process. Citric acid (CI) and sodium bisulfite (SB) are two chemicals that are widely used in membrane feed water pretreatment and cleaning processes. In this work, preadsorptions of CI and SB were developed as simple methods for polysulfone ultrafiltration membrane modification. It was found that hydrogen bonding and Van Der Waals attraction could be responsible for the adsorptions of CI and SB onto membranes, respectively. After modification with CI or SB, the membrane surfaces became more hydrophilic. Membrane permeability improved when modified by SB while decreased a little when modified by CI. The modified membranes had an increase in PEG and BSA rejections and better antifouling properties with higher flux recovery ratios during filtration of a complex pharmaceutical wastewater. Moreover, membrane chlorine tolerance was elevated after modification with either agent, as shown by the mechanical property measurements.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.2
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• pp.120-129
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• 2023

Marine structures are subject to damage not only from sea salt but also from the adhesion of marine microorganisms and suspended particles, which cause additional damages. In order to prevent this, periodic coating is employed in the case of vessels to maintain the necessary performance. However, it is true that periodic coating is difficult for concrete or steel support structures, and there is a risk of marine environmental pollution. In this study, authors developed an anti-fouling coating agent using eco-friendly materials that possess hydrophilic cellulose nanofibers and AKD(alkyl ketene dimer). To achieve a homogeneous mixture, the content of cellulose nanofibers was fixed at 1 %, and AKD, distilled water, and waste glass were mixed using a digital mixer and homogenizer. The contact angle of the prepared coated surface was observed to be over 130°, indicating sufficient performance even in a water droplet flow test with a 15° slope, suggesting self-cleaning capability. Furthermore, through the analysis of viscosity characteristics at different temperatures, it was confirmed that the application is feasible at room temperature. Microstructure analysis also verified that the coating agent is uniformly applied to the concrete surface.

• Journal of Marine Life Science
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• v.5 no.1
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• pp.9-16
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• 2020

We evaluated the toxic effects of antifouling paint (irgarol and diuron) on the population growth rate (r) of the marine diatom, Skeletonema costatum. The r of S. costatum was determined after 96 hrs of exposure to irgarol (0, 0.31, 0.63, 1.25, 2.5 and 5 ㎍ l^-1) and diuron (0, 7.81, 15.63, 31.25, 62.5 and 125 ㎍ l^-1). It was observed that r in the control (absence of irgarol and diuron) were greater than 0.04, while r in the treatment groups decreased with increasing irgarol and diuron concentrations. Irgarol and diuron reduced r in a dose-dependent manner with significant decreases occurring at concentrations above 0.63 and 15.63 ㎍ l^-1, respectively. The EC₅₀ values of r in irgarol and diuron exposure were 1.09 and 45.45 ㎍ l^-1. No observed effect concentration (NOEC) were 0.31 and 7.81 ㎍ l^-1, the lowest observed effect concentration (LOEC) were 0.63 and 15.63 ㎍ l^-1. This result indicate that a concentration of greater than 0.63 ㎍ l^-1 of irgarol and 15.63 ㎍ l^-1 of diuron in marine ecosystems induced to decreasing r of S. costatum. Also, these toxic values can be useful as a baseline data for the toxic evaluation of irgarol and diuron in marine ecosystems.