• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1990년도 제2차 학술발표초록집
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• pp.36-37
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• 1990

In the past, facile dissolution of cellulose has been hampered by the lack of suitable nondegrading solvents. Recently, this problem has been solved in our laboratory by the discovery of an inexpensive, convenient solvent system, that is the mixture of $NH_3\;and\;NH_4SCN$, for cellulose. Also, the $cellulose/NH_3/NH_4SCN$ solution system has been found to form the anisotropic, i.e., liquid crystalline phase. It is believed that both the cholesterio and the nematic phase occur. This finding has prompted extensive on-going researoh on the formation of the liquid crystalline phase from an inexpensive natural source such as cellulose since the nematic phase is envisioned as an excellent precursor sources for products with desirable properties, for example, high modulus and high strength. This interest naturally leads to a desire to understand the theological properties of the nematic phase so that the transformation of the nematic phase to the solid state with desirable properties can be efficiently accomplished, ;From this point of view, the theological behavior of the $cellulose/NH3_/NH_4SCN$ system has been studied as a function of shear rate and shear stress over a wide range of solvent compositions, cellulose concentration, centrifugation and urea contents, Results indicate that the viscosity decreases with increasing shear rate. A marked shear thinning behavior and a quasi-Newtonian behavior were observed in the low shear rate region and in the high shear rate region, respectively for all solvent compositions. The $cellulose/NH_3/NH_4SCN$ solution system only exhibited the viscosity increase with increasing cellulose concentration and failed to show the viscosity drop generally observed at the point of incipience of liquid crystal formation, This may be due to the gel-like nature of the solution by the association of the rodlike molecules into bundles which may serve as crosslinking points giving the cellulose solution a network structure. Also, simply hydrogen bonding may be so restrictive of molecular mobility that a viscosity drop is blocked. In addition to the above results, yield stress and thixotropy were also observed in the $cellulose/NH_3/NB_4SCN$ solution system which are characteristics of liquid crystal and gel, The results of the effect of centrifugation on viscosity show that viscosity decreases by the application of centrifugation. This may be explained by the change of the piled polydomain structure to the dispersed polydomain structure due to the pressure gradient generated during centrifugation.ation.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.630-634
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• 2011

Solvent-free conversion of various epoxides to their corresponding $\beta$-hydroxy thiocyanates was carried out successfully with $NH_4SCN$/zeolite molecular sieve $4{\AA}$ system at room temperature. The reactions were completed within 2 - 7 min to give thiocyanohydrins with perfect regioselectivity and isolated yields. Moreover, the zeolite can be reused for several times without losing its activity.

• Environmental Engineering Research
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• 제24권2호
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• pp.254-262
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• 2019

The impact of free cyanide ($CN^-$) and thiocyanate ($SCN^-$) on the $CN^-$ (CDO) and $SCN^-$ degraders (TDO) to nitrify and denitrify aerobically was evaluated under alkaline conditions. The CDO's were able to nitrify under cyanogenic conditions, achieving $NH_4{^+}-N$ removal rates above 1.66 mg $NH_4{^+}-N.L^{-1}.h^{-1}$, except when $CN^-$ and $SCN^-$ loading was 15 mg $CN^-/L$ and 50 mg $SCN^-.L^{-1}$, respectively, which slightly inhibited nitrification. The TDO's were able to achieve a nitrification rate of 1.59 mg $NH_4{^+}-N.L^{-1}.h^{-1}$ in the absence of both $CN^-$ and $SCN^-$, while the presence of $CN^-$ and $SCN^-$ was inhibitory, with a nitrification rates of 1.14 mg $NH_4{^+}-N.L^{-1}.h^{-1}$. The CDO's and TDO's were able to denitrify aerobically, with the CDO's obtaining $NO_3{^-}-N$ removal rates above 0.67 mg $NO_3{^-}-N.L^{-1}.h^{-1}$, irrespective of the tested $CN^-$ and $SCN^-$ concentration range. Denitrification by the TDO's was inhibited by $CN^-$, achieving a removal rate of 0.46 mg $NO_3{^-}-N.L^{-1}.h^{-1}$ and 0.22 mg $NO_3{^-}-N.L^{-1}.h^{-1}$ when $CN^-$ concentration was 10 and 15 mg $CN^-.L^{-1}$, respectively. However, when the CDO's and TDO's were co-cultured, the nitrification and aerobic denitrification removal rates were 1.78 mg $NH_4{^+}-N.L^{-1}.h^{-1}$ and 0.63 mg $NO_3{^-}-N.L^{-1}.h^{-1}$ irrespective of $CN^-$ and $SCN^-$ concentrations.

• Elastomers and Composites
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• 제34권1호
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• pp.3-10
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• 1999

아크릴로니트릴(AN) 단일중합체를 항온장치가 부착된 광중합반응기내에서 합성하여 최적반응조건하에서 중합속도모델식을 구하였다. AN의 농도($1.8{\sim}7.58mo1/1$), 증감제의 종류($NaSCN,\;KSCN,\;Ba(SCN)_2,\;NH_4SCN,\;ZnCl_2,\;Na_2SeO_3$) 및 농도($10{\sim}60%$), 반응온도($10{\sim}70^{\circ}C$), 에너지 세기($1,000{\sim}9,900{\mu}J/cm^2$)를 변화시켰다. 광증감제의 농도에 관계없이 반응온도 $50^{\circ}C$, 반응시간 3시간에서 균일한 분자량분포를 얻고, 이중 광증감제로 50%의 NaSCN의 경우 다음과 같은 중합속도 모델식을 구하였다. $R_p=0.0142[M]^{0.82}[I]^{0.49}[S]^{0.52}$ exp(-1.33/RT).

• 약학회지
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• 제7권2_3호
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• pp.36-41
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• 1963

Cobalt thiocyanate ion에 미치는 영향을 연구하였다. Cobalt ion이 $NH_{4}CNS$ 용액에 의해서 생성되는 ion의 색의 transmittance는 확산에 의하여 적어지며, 황산존재하에서는 황산의 양과 Transmittance 사이에 비례적 관계가 있다. 염산 및 질산도 역시 Transmittance의 값에 영향을 미치기는 하나 염산의 경과에는 이 착 ion이 황산존재하보다 다소 불안정하며 질산에 의해서는 안정화가 극히 적어서 단시간내에 Perthiocyanuric acid로 인정되는 물질로 분해한다. 또한 그 Transmittance가 과량의 광산존재하에서 적어지는 현상으로 부터 $Co(SCN)^{2-n/_{$ n/의 n의 값이 커지는 것은 ether에 이행하는 SCN-을 Volhard 씨법으로 정량함으로서 확증하였다.

• 한국결정학회지
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• 제12권4호
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• pp.207-211
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• 2001

Cd(SCN)₂{CH/sub 6/H/sub 10/(NH₂)₂}₂(1) 착물을 합성하고 단결성 X-선 회절법으로 구조를 규명하였다. 이 착물은 단사정계, 공간국 P2₁/ space group with a=11.842(2), b=7.926(2), c=11.291(2) Å, β=106.73(3)°V=1014.8(4)Ų, Z=2 로 결정화되었으며, 1775 개의 독립적인 회절반점에 대한 최종 신뢰도 인자 R₁및 ωR₂값은 각각 0.0518 및 0.1315이었다. 착물의 결정 구조는 2개의1,2-Diaminocyclohexane리간드의 질소 원자 xy 평면에서 Cd(II) 금속원자에 chelate 되어 5-membered ring을 형성하며, 2개의 thiocyanate 리간드의 황 원자가 z 축 방향으로 Cd(II) 금속 원자에 트란스 형태로 결합함으로 써 z축 방향으로 약간 늘러진 팔면체 구조의 착물을 형성한다.

• 분석과학
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• 제12권3호
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• pp.243-247
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• 1999

HCl 산성에서 aconitine류 알칼로이드는 Reineke 시액으로 백색의 침전을, 그리고 TCR 시액으로 청색의 침전을 형성하였다. 백색의 침전은 $NH_4OH$ 알칼리성의 물에 녹아 aconitine류 알칼로이드를 유리시키며, 유리된 aconitine류 알칼로이드는 DCE층으로 쉽게 전용되었다. 전용된 DCE층을 분취하여 UV흡광파장을 측정하고 TLC로 분리하였다. 청색의 침전은 DCE층에 전용되므로 전용된 DCE층을 분취하여 UV/Vis.흡광파장을 측정하였다. 이상의 방법으로 aconitine류 알칼로이드를 검출하여 생약이나 제제에서 aconitine류 알칼로이드를 함유한 부자류 생약을 확인할 수 있었다.

• 약학회지
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• 제7권2_3호
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• pp.67-71
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• 1963

Studies the reaction mechanism and optimal reaction condition of the process of preparing sodium isocyanate, by means of heating of sodium carbonate and urea. Proposing, at the sametime, the quantitative analyzing method of sodium isocyanate in the presence of impurities of $Na_{2}CO_{3}$, urea and biuret. 1. Sodium isocyanate could be prepared by means of heating reaction of sodium carbonate and urea. 2. Adding urea into the heated sodium carbonate is reasonable. 3. Quantitative analysis of sodium isocyanate in the presence of impurities, $Na_{2}CO_{3}$, urea and biuret could be done by the following method:-adding nitrobarite solution into sample solution in order to remove $CO_{3}"$ and neutralize the solution, filtering off $BaCO_{3}$, and then precipitating isocyanate as a silver salt, filtering off AgNCO, and then, titrating remaining $AgNO_{3}$ with $NH_{4}SCN$, (indicator $FeNH_{4}(SO_{4})_{2})$/TEX>

• 자원리싸이클링
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• 제31권1호
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• pp.21-28
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• 2022

폐리튬이온배터리를 고온에서 용융환원시키면 코발트, 니켈 및 구리 금속합금상을 얻을 수 있다. 이러한 금속합금상으로부터 금속을 분리회수하기 위한 공정을 개발하기 위해 코발트, 니켈 및 구리 금속을 혼합한 금속혼합물을 3% 과산화수소를 함유한 2 M 황산용액으로 침출하면 9.6%의 구리와 함께 코발트와 니켈이 모두 침출된다. 침출용액에서 Cyanex 301로 구리(II)가 선택적으로 추출되었으며, 30% 왕수로 구리(II)를 탈거했다. 구리가 분리된 여액에서 이온성액체인 ALi-SCN으로 Co(II)를 선택적으로 추출했으며, 15%의 암모니아용액으로 3단의 교차식 탈거를 통해 모두 탈거했다. 본 연구를 통해 코발트, 니켈 및 구리 금속혼합물의 황산침출액에서 용매추출로 세 금속을 분리할 수 있는 공정을 제안했다.

• Journal of Microbiology and Biotechnology
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• 제10권1호
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• pp.48-50
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• 2000

The energetics at the succinate:quinone oxidoreductase segment of V. alginolyticus was studied using a fluorescence quenching technique with inside-out membrane vesicles. A transient generation of the membrane potential (inside-positive) and ${\Delta}pH$ (inside-acidic) occurred in the presence of KCN and succinate when ubiquinone-1 (Q1) was added. The membrane potential (\Delta\psi$) generated by the succinate; quinone oxidoreductase segment was completely collapsed by the protonophore carbonylcyanide m-chlorophenylhydrazone (CCCP) and the membrane permeable anion $SCN^{-}$, whereas the ${\Delta}pH$ was completely collapsed by CCCP and $(NH_4)_2SO_4$. From these results, it was concluded that the succinate: quinone oxidoreductase segment as well as quinol oxidase [1] in the respiratory chain of V. alginolyticus generated $H^{+}$ electrochemical potential.