• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.3
• /
• pp.274-285
• /
• 1996

These experiments were conducted to evaluate the effects of seed coating with ten environmentally acceptable polymers, on germination percentage, water uptake, respiration, emergence and seedling growth characteristics. The water absorption of polymer-coated seeds in saturation condition was highest in klucel and lowest in polyvinyl pyrrolidone(PVP), and that in water was highest in klucel and lowest in maltrin. Respiration rates of polymer-coated seeds in Hwayoungbyeo and Ilpumbyeo were lower than those of none-coated seeds, and those in Daecheongbyeo and Jinmibyeo were higher than that of none-coated seeds, and those of sepiret coated seeds were higher than PVP coated seeds. The germination polimer-coated seed was reduced by one percentage by coating with seed coating machine. Germination percentage was not affected by any of polymer coating in high quality seed, but there were significant effects in low quality seed coating with waterlock, surelease 46 and sepiret significantly reduced germination some cultivars. Germination percentage after accelated ageing treatment were slightly higher most of polymer-coated seeds than in none-coated seeds, but those of sepiret-and klucel-coated seeds were lower significantly. Germination percentage of seeds coated with daran 8600, rnaltrin, sacrust and opadry were enhanced slightly under cold test other polimers reduced germination. The seedling height of polymer-coated seeds were longer than those of none-coated seeds, but those of waterlock, PVP and maltrin coating seeds were shorter, seedling hight was shortened by polimer coating under cold test. Polymer-coated seeds showed higher emergence percentage, shorter emergence time in field condition. The highest emergence percentage and the shortest emergence time was shown at 90% soil moisture content.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.43 no.3
• /
• pp.147-151
• /
• 1998

The conductivity test is a measure of electrolytes leakage from plant tissue. The shorter the maturation period after heading was the greater electrical conductivity (EC) of rice seed. The polymer-coated seed was not different in EC compared with non-coated seed. As soaking time of rice seed increased, EC increased gradually. The EC varied from 9.9 to 20.7$\mu$S $cm^{-1}g^{-l}$ for control plots and from 21.3 to 41.7$\mu$S $cm^{-1}g^{-l}$ for heat-killed seeds which were produced by autoclaving seeds at 121$^{\circ}C$ for 20 minutes. The germination speed (the rate of 5th day) of rice seed was 94% at control plot, 83% at low temperature and 20% at high temperature. Besides, germination percentage was 95% for the control, 92% for the low temperature treatment and 39% for the high temperature treatment. The EC was negatively correlated (r=-0.771$^{**}$) with germination percentage at low temperature. Water uptake in seeds of 30, 40, 50 days after heading (DAH) was greater than that of 20 DAH. Plant height of seedlings was 9.84 cm for the control but 4.32 cm for the high temperature treatment, and the tallest for polymer-coated seed. Dry weight of seedlings was 0.841 g for the control and 0.287 g at high temperature. Besides, the polymer-coated seed was heavier than non-coated seed. The number of roots was largest from 40 to 50 DAH and polymer-coated seed, but was decreased from 20 to 30 DAH. The length of roots was 20.52 cm at control plot and 19.89 cm polymer-coated seed but 8.68 cm for the low temperature treatment and 7.28 cm for the high temperature treatment.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.43 no.4
• /
• pp.214-222
• /
• 1998

These experiments were conducted to investigate water uptake, electrical conductivity, germination percentage, seedling growth, and seedling establishment rate in direct seeding cultivation of rice. The rice seeds of six japonica type varieties were coated with 12 kinds of polymers in a standard concentration of 0.2% using seed coating machine. The water absorption of the polymer-coated seeds under saturation conditions was not different among varieties, and was the highest in kulcel, maltrin, and waterlock on the polymer-coated seeds. The electrical conductivity with waterlock (55.0 $\mu scm^{-1}g^{-1}$) was higher than the control plot (45.6 $\mu scm^{-1}g^{-1}$) and other treatments. The germination of the polymer-coated seeds was 95.9% at control plot, 92.7% at low temperature and 35.7% at high temperature. The total dry weight of seed decreased in the order of low temperature, control plot, and high temperature, and was effective in pvp (polyvinyl pyrrolidone), opadry, and sacrust. The seedling establishment rate in direct seeding cultivation ranged from 74.9 to 81.0% in flooded paddy surface, and ranged from 64.7 to 76.6% in dry paddy. In both cases, it decreased in the order of early, medium and medium-late varieties, but was enhanced in daran 8600, sepirect, and sacrust. According to this study the recommended polymers for direct seeding cultivation of rice are daran 8600, sepirect, and sacrust.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.429.2-429.2
• /
• 2014

ZnO nanowire is known as synthesizable and good mechanical properties. And, stimuli-responsive polymer is widely used in the application of tunable sensing device. So, we combined these characteristics to make precise tunable sensing devise. In this work, we investigate the dependence of ZnO nanowire alignment and morphology on si substrate using nanosphere template with various conditions via hydrothermal process. Also, pH-temperature dependant tuning ability of nanostructure was studied. The brief experimental scheme is as follow. First, Zno seed layer was coated on a si wafer ($20{\times}20mm$) by spin coater. And then $1.15{\mu}m$ sized close-packed PS nanospheres were formed on a cleaned si substrate by using gas-liquid-solid interfacial self-assembly method. After that, zinc oxide nanowires were synthesized using hydrothermal method. Before the wire growth, to specify the growth site, heat treatment was performed. Finally, NIPAM(N-Isopropylacrylamide) was coated onto as-fabricated nanostructure and irradiated by UV light to form the PNIPAM network. The morphology, structures and optical properties are investigated by FE-SEM(Field Emission Scanning electron Microscopy), XRD(X-ray diffraction), OM(Optical microscopy), and WCA(water contact angle).

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.2
• /
• pp.145-156
• /
• 1996

The effects of priming with different polyethylene glycol (PEG 6, 000) solutions on the germination, emergence characteristics and early plant growth in rice, barley and wheat were investigated. Rice, barley and wheat seeds were subjected to various priming conditions of osmotic potentials (-0. 75, -1.00 and -1.50 MPa) of PEG, and incubation period were 5 days at 25, 20, 2$0^{\circ}C$, respectively. The percentage of water absorption was highest in barely, and lowest in rice, and all the treatments enhanced water absorption in barley, but showed no significant effects in rice and wheat. Respiration quotient was lower than none PEG treatment seeds, and those of barley and wheat were higher than rice regardless of PEG concentration, and that of rice increased with high PEG concentration. Total germination percentage of osmoconditioning seeds with PEG was higher than that of none treatment seed, and those of barley and wheat were significant. The artificially deteriorated seeds with PEG treatment seeds after ageing treatment could recover to nearly the same germination level as that of the control seeds. The effects of coating polymer were higher than osmoconditioning with PEG, and germination characteristics in rice showed varietal difference at PVP and waterlock at recoated seeds after PEG treatment. Osmoconditioning with PEG reduced mean germination and emergence time, but there was no difference among PEG concentrations. The plant height of PEG treaed seed in rice was taller and those of barely and wheat showed varietal difference, and those of polymer-coated seed after PEG treatment were different among the polymers. The dry weight of PEG treatment were different among the crops, and those were increased with the high PEG concentration. The emergence percentage of PEG-treated seed were higher than none-treated seed, and those were decreased with the increased PEG concentration, and the highest emergence percentage of rice, barley and wheat were 90, 50 and 50% soil moisture content, respectively. The time to emergence in rice was longer than barley and wheat, and those in rice was shortened in high soil moisture content, and barley and wheat were shortened in low soil moisture content.

• Polymer(Korea)
• /
• v.32 no.4
• /
• pp.322-327
• /
• 2008

In this study, a multi-layered pellet was composed of a seed layer including a water-swellable agent and a drug layer containing doxazosin as a model drug, a porous membrane and a castor oil layer to control drug release. The pellet is prepared by a fluidized bed coating method. To confirm drug release from polymer blending in multi-layered pellet system, it is prepared by containing different ratio such as hydroxypropylmethylcellulose (HPMC) : ethyl cellulose (EC) in drug layer and cellulose acetate(CA) : Eudragit RS in membrane. Also, to confirm the effect of oil in drug release, castor oil is coated. As a result, we observed regularly spherical pellet with diameter of $1500{\mu}m$. Release pattern of drug is confirmed by dissolution tester in aqueous media. The more the ratio of EC in drug layer, CA in membrane, and castor oil layer in pellet, the less the drug release is observed. Formation and the amount of pores in membrane is observed by SEM.

• Polymer(Korea)
• /
• v.32 no.2
• /
• pp.103-108
• /
• 2008

Osmotic pellet, which consisted of water-swellable seed layer, drug layer, and porous membrane layer, has been widely utilized in oral drug delivery system. In this work, we describe the preparation of osmotic pellet with nifedipine as model drug and a mixture of cellulose acetate (CA) and Eudragit RS as membrane layer, and then examined the drug release behavior on the variation of the thickness change of membrane layer (CA and Eudragit RS) and release media. Furthermore, we examined the nifedipine release behavior using sodium alginate as a potential membrane candidate. Osmotic pellet was obtained in the quantitative yield by fluidized bed coater. Osmotic pellet exhibited the round morphology and the size ranging $1500{\sim}1700{\mu}m$ in SEM. The nifedipine release decreased as the thickness of membrane layer (CA and Eudragit RS) increased. In addition, it observed that there is difference of release amount in between intestinal juice (pH 6.8) and gastric juice (pH 1.2). In the case of osmotic pellet coated with sodium alginate, nifedipine release behavior depended on the crosslinking of sodium alginate layer. In conclusion, we found that various membrane layers could control the release amount of nifedipine.