POLYMERS Vol.62 No.8
>> Chinese >> English >> Japanese >> Korean
COVER STORY
Environmental Purification Materials
COVER STORY: Highlight Reviews
Do We Need New Materials for Environmental Remediation? Izumi ICHINOSE
<Abstract> It is not easy to solve the ongoing issues of worldwide environmental pollution. Polymer-based separation-functional materials have contributed to various environmental protection activities by being used as filters, water treatment membranes, flocculants, adsorbents, etc. However, the remediation of the environment that has been polluted in the past will be a long-term challenge of a few decades. In this review, the ways of the polymer-based materials research for environmental protection will be discussed in view points of durability and recyclability of the materials. Especially, new separation materials required for natural resources development such as oil, gas, and minerals are introduced.
Keywords: Separation Membrane / Produced Water / Diamond-Like Carbon / Adsorbent
Top of the Page▲
Development of New Macro-Porous Polymers Contributing to Assessment and Improvement of Environmental Pollutions Ken HOSOYA
<Abstract> A variety of macro-porous polymers has been utilized for environmental clean-up, for example, adsorption, separation, as well as removal of organic pollutants in aqueous environment. Herein, essential advantages and practicable applications of macro-porous organic polymers, which our research group has studied, especially, new concepts and practicable methods for hydrophilic organic pollutants will be reviewed. First of all, selectivity using a new concept MIP (molecular imprinting polymer) and a multi-dimensional adsorption and exclusion mechanism by surface modified macro-porous polymer will be introduced. Afterwards I will introduce the advantages of an automated HPLC (high performance liquid chromatography) system having multi-switching valves for pre-concentration of really dilute pollutants. Finally I will briefly focus on practically applicable polymers such as spongy monoliths, adsorption media with photo-catalyst, as well as macro-porous polymers having anti-bacterial actions.
Keywords: Macro-porous Polymer / Monolith / Environmental Pollutant / Pre-treatment / Solid Phase Extraction / HPLC / MIP / Anti-Bacterial Action
Top of the Page▲
COVER STORY: Topics and Products
Removal of Cs(I) and Sr(II) by Ion Exchange Resins and Chelate Resins Katsuhiko YANO
<Abstract> Selective removal of Cs(I) and Sr(II) from waste water is needed in Fukushima Nuclear Power Station. We have estimated various types of ion exchange resins and chelate resins. Sulfonic-acid type cation-exchange resins and iminodiacetic-acid type chelate resins are effective for Cs(I) and Sr(II) adsorption from waste water. These adsorbents are based on aromatic copolymers, but resistant to some level of γ-ray irradiation. They show that ion exchange resins and chelate resins are available for Cs(I) and Sr(II) removal from waste water.
Keywords: Ion Exchange / Chelate / Cs / Sr / Removal
Top of the Page▲
Radioactive Cs-Decontamination from Aquaus Waste by Nanoparticles Tohru KAWAMOTO
<Abstract> Since 2011, the radioactive Cs-decontamination from the environment is the serious problem in Japan. Prussian blue (PB), one of the famous coordination polymers, is the well-known good adsorbent for Cs-ion. We have drastically improved the Cs-adsorption performance of PB by the control of its nanostructure and fabrication of the composite with other materials. These new adsorbent will contribute the decontamination around the Fukushima prefecture.
Keywords: Prussian Blue / Radioactive Cs / Waste / Decontamination / Nanoparticles
Top of the Page▲
Removal of Radioactive Cesium by Polymer Hitoshi MIMURA
<Abstract> Large amounts of high-activity-level water accumulated in the reactor, turbine building and the trench in the facility that were generated from the nuclear accident of Fukushima NPP-1 caused by the Great East Japan Earthquake. This contaminated water resulted in operation obstacles and environmental contamination. At present, the cold shutdown is completed by the circulating injection cooling system, while large amounts of high-activity-level water, over 260,000 m3, are stored in Fukushima NPP-1. In order to develop high selective adsorbents towards radioactive cesium, functional polymers can be used for the immobilization of selective fine adsorbents. By using the alginate gel polymer enclosing insoluble ferrocyanides and heteropolyacids, complete removal of radioactive Cs can be accomplished from seawater. Non woven Zeolite was also effective for the selective removal of radioactive cesium in the field of soil decontamination. Functional polymers are thus useful for the decontamination of radioactive cesium and environmental remediation.
Keywords: High-Activity-Level Water / Radioactive Cesium / Functional Polymer / Immobilization / Alginate Gel Polymer / Zeolite Non Woven / Decontamination
Top of the Page▲
Development of Fibrous Grafted Adsorbents for Environmental Remediation Noriaki SEKO
<Abstract> Water contamination with toxic metals causes serious human health problems. Environmental functional materials can contribute to environmental conservation such as removal of toxic metal. These functions were introduced into the artificial polymers by radiation graft polymerization. Graft polymerization can change the conventional polymer to act as metal adsorbents, which realizes rapid adsorption and easy handling. The synthesized fibrous adsorbents were used in a field test to achieve removing of dissolved radioactive cesium in Fukushima Pref., which was conducted successfully. Furthermore, a water purifier for cesium removal has been developed and is expected to be applied soon.
Keywords: Environment Purification and Preservation / Radiation Graft Polymerization / Toxic Metals / Radioactive Cesium
Top of the Page▲
Development of Energy Saving Fluororesin Media Hitoshi NIINUMA, Yoshiyuki SHIBUYA, Li BAO
<Abstract> We developed new fluororesin media with large pore size and thickness. It has high efficiency, low pressure-drop and long service-life which is similar to that of fiberglass media mainly used as HEPA filter media. The new HEPA filter with fluororesin media has lower pressure-drop than the fiberglass filter and a longer service-life than the conventional PTFE filter. Therefore it is possible to reduce the energy consumption at the operating stage of HEPA filters and we can provide an energy saving product that is reducing CO2 emission.
Keywords: Air Filter / Fiberglass Media / Fluororesin Media / Low Pressure Drop / Long Service Life / Energy Saving
Top of the Page▲
Removal Characteristic of Activated Carbon Fiber for Radioactive Iodine Makoto INOUE
<Abstract> An activated carbon fiber (ACF) is fibrous activated carbon which has many micro pores in the surface, and shows the characteristic outstanding as adsorbent.
Especially the activated carbon fiber containing 1,4-Diazabicyclo[2.2.2] octane (DABCO) shows the removal performance which was excellent under high humidity to the radioactive methyl iodide, and is used as a filter for the local ventilation of a nuclear power plant.
Keywords: Activated Carbon Fiber / Radioactive Iodine / DABCO / Filer / Local Ventilation / Nuclear Power Plant
Top of the Page▲
Polymer Science and I: A Personal Account
Roaming... Shoichi KUBO
<Abstract> Roaming various research laboratories gave me many acquaintances and a wide variety of research topics. Now I'm going to put my available materials together in order to create functional nano materials based on amazing polymers.
Top of the Page▲
Front-Line Polymer Science
Cancer-Specific DDS Using Stimuli-Responsive Polymers Yoshiki KATAYAMA
<Abstract> Cancer chemotherapy has a serious difficulty with its poor cell specificity. DDS using nano-medicine consisting of polymer materials will be one of the most promising strategies to address this issue. Almost all cancer nano-medicines uses enhanced permeability and retention effect (EPR effect) based on extravasation of huge molecules in tumor neovasculature. As an additional effect, cancer specific ligand-receptor interaction is also available to enhance the binding ability of nano-medicine to cancer cells. Although these strategies realize significant drug accumulation in tumors compared with small drug administration, greater amount of nano-medicine may still be distributed to other non-target organs. In this context, Stimuli-responsive polymers have been applied to enhance the contrast of drug concentration between tumor and normal cells. In this review, recent progress of cancer DDS materials using a stimuli-responsive strategy is reviewed. Future directions for ideal cancer nano-medicine is also considered.
Keywords: DDS / Nanomedicine / Stimuli-Responsive Polymer / Drug Carrier / Gene Delivery / Drug Delivery / Cancer
Top of the Page▲