• 한국결정성장학회지
• /
• 제23권2호
• /
• pp.101-107
• /
• 2013

재생 세륨 전구체로부터 수산화세륨($Ce(OH)_3$), 염화세륨($CeCl_3{\cdot}nH_2O$), 탄산세륨($Ce_2(CO_3)_3{\cdot}8H_2O$) 및 산화세륨($CeO_2$)을 합성하고 Ultra-sonication을 통해 나노입자의 산화세륨(IV)을 제조하였다. 폐 유리연마재로부터 정제한 약 99 wt% 재생 세륨 분말을 출발물질로 하여 황산침출과 황산나트륨의 첨가조건을 통해서 황산나트륨세륨 화합물($CeNa(SO_4)_2$)을 합성하였다. 또한 황산나트륨세륨 화합물과 수산화나트륨 수용액 첨가량 비의 조건을 달리하여 수산화세륨을 제조하였으며 염산의 첨가량에 따라 염화세륨을 합성하였다. 연속적인 합성공정으로 침상형의 탄산세륨을 합성한 후 하소와 분산을 통해서 평균 30~40 nm의 산화세륨(IV)을 합성하였다.

• 공업화학
• /
• 제8권5호
• /
• pp.866-871
• /
• 1997

전분의 친수성 및 반응성을 조절하기 위하여 propylene oxide, 1,2-epoxybutane, glycidyl methacrylate, maleic anhydride, caprolactone 등을 반응시켰으며 건조되지 않은 전분을 사용할 경우 propylene oxide, maleic anhydride 외에는 반응 수율이 아주 낮아지는 것이 관찰되었다. 이렇게 개질된 전분을 스티렌과 반응시켜 그라프트 공중합물로 전환하였으며 여러가지 중합방법에 대한 그라프트 수율이 비교되었다. 그라프트 중합반응의 경우 용액중합 및 cerium(IV)이온에 의한 중합은 각각 낮은 효율과 수율을 보였다. 현탁중합 방법으로는 전분 입자의 친수성 때문에 폴리스티렌으로 전분을 encapsulation 하기가 어려웠으며, 유화중합이 스티렌을 그라프트 시키기에 제일 적당한 방법임을 알 수 있었다.

• 한국수소및신에너지학회논문집
• /
• 제26권6호
• /
• pp.524-531
• /
• 2015

To improve the electrochemical and mechanical characteristics, engineering plastic of the sulfonated polyether ether ketone (SPEEK) as polymer matrix was prepared in the sulfonation reaction of polyether ether ketone (PEEK). The SPEEK organic-inorganic blended composite membranes were prepared by sol-gel casting method. It was loaded with the highly dispersed ceria and cesium-substituted molybdosilicic acid (Cs-MoSiA) and 1,4-diiodobutane which was cross-linking agent contents of $10{\mu}L$. Cs-MoSiA was added to increase proton conductivity. Ceria ($CeO_2$) was used as a free radical scavenger which degrade the membrane in polymer electrolyte membrane water elctrolysis (PEMWE). In conclusion, CL-SPEEK/Cs-MoSiA/Ceria 1% composite membrane showed high proton conductivity 0.2104 S/cm at $25^{\circ}C$ which was better than Nafion 117 membrane.

• 한국수소및신에너지학회논문집
• /
• 제25권6호
• /
• pp.561-569
• /
• 2014

Ceria ($CeO_2$) was used to increase the durability of the membrane in the polymer electrolyte membrane water electrolysis (PEMWE) circumstance. The sulfonated polyether ether ketone (SPEEK) as polymer matrix was prepared in the sulfonation reaction of polyether ether ketone (PEEK) to improve electrochemical characteristics. After sulfonation reaction, the organic-inorganic blended composite membranes were prepared by means of sol-gel casting method with loading the highly dispersed $CeO_2$ and Cs-substituted molybdophosphoric acid (Cs-MoPA) with cross-linking agent (tetrapropyl orthosilicate). Consequently, the composite membrane CL-SPEEK/Silane 4wt%/Cs-MoPA/Ceria(1%) showed the improved characteristics such as 82% of water content, 0.11136 S/cm of proton conductivity at $80^{\circ}C$, 55.50 MPa of tensile strength and 4.37% of breeding out of MoPA.

• 한국수소및신에너지학회논문집
• /
• 제26권3호
• /
• pp.212-220
• /
• 2015

The engineering plastic of sulfonated polyether ether ketone (SPEEK) as a polymer matrix has been developed in this lab to replace Nafion, solid polymer electrolytes of perfluorosulfonic acid membrane which has several flaws such as high cost, and limited operational temperature above $80^{\circ}C$. The SPEEK was prepared in the sulfonation reaction of polyether ether ketone (PEEK). The organic-inorganic blended composite membranes were prepared by sol-gel casting method with loading the highly dispersed ceria and cesium-substituted tungstosilicic acid (Cs-TSiA) with cross-linking agent contents of 0.01 mL. In conclusion, CL-SPEEK/Cs-TSiA/ceria 1% membrane showed the optimum results such as 0.1882 S/cm of proton conductivity at $80^{\circ}C$, and 99.61 MPa of tensile strength which were better than Nafion 117 membrane.

• 한국수소및신에너지학회논문집
• /
• 제25권2호
• /
• pp.151-160
• /
• 2014

CL-SPEEK/Cs-TPA/$CeO_2$ composite membrane was prepared for polymer electrolyte membrane water electrolysis (PEMWE). In order to improve the electrochemical, mechanical, durabilities and electrocatalytic characteristics, engineering plastic of polyether ether ketone (PEEK) as polymer matrix was sulfonated and the organic-inorganic blend composite membranes was prepared by loading cesium-substituted tungstophosphoric acid (Cs-TPA) by titration method with cross-linking agent contents of 0.01mL. Ceria ($CeO_2$) was used to scavenge free radicals which attack the membrane in the PEMWE circumstance and to increase the duration of the membrane. CL-SPEEK/$Cs_{(1)}$-TPA/CeriaIn conclusion, 1% membrane showed the optimum results such as 0.119 S/cm at $80^{\circ}C$ of proton conductivity and 62MPa of tensile strength.

• 한국수소및신에너지학회논문집
• /
• 제25권1호
• /
• pp.1-10
• /
• 2014

Ceria ($CeO_2$) was used to scavenge free radicals which attack the membrane in the polymer electrolyte membrane water electrolysis (PEMWE) circumstance and to increase the duration of the membrane. In order to improve the electrochemical, mechanical and electrocatalytic characteristics, engineering plastic of the sulfonated polyether ether ketone (SPEEK) as polymer matrix was prepared in the sulfonation reaction of polyether ether ketone (PEEK) and the organic-inorganic blended composite membranes were prepared by sol-gel casting method with loading the highly dispersed ceria and cesium-substituted phophomolybdic acid(Cs-MoPA) with cross-linking agent contents of 0.01mL. In conclusion, CL-SPEEK/$Cs_{(2.5)}$-MoPA/ceria(1%) membrane showed the optimum results such as 0.1095S/cm of proton conductivity at $80^{\circ}C$, 2.906meq./g-dry-membrane of ion exchange capacity and mechanical characteristics, and 49.73MPa of tensile strength which were better than Nafion 117 membrane.

• 한국수소및신에너지학회논문집
• /
• 제23권5호
• /
• pp.437-447
• /
• 2012

Ceria ($CeO_2$) was used to scavenge free radicals which attack the membrane in the polymer electrolyte membrane water electrolysis (PEMWE) circumstance and to increase the duration of the membrane. In order to improve the electrochemical, mechanical and electrocatalytic characteristics, engineering plastic of the sulfonated polyether ether ketone (SPEEK) as polymer matrix was prepared in the sulfonation reaction of polyether ether ketone (PEEK) and the organic-inorganic blended composite membranes were prepared by sol-gel casting method with loading the highly dispersed ceria and cesium-substituted tungstophosphoric acid (Cs-TPA) with cross-linking agent contents of 0.01 mL. In conclusion, CL-SPEEK/Cs-TPA/ceria (1%) membrane showed the optimum results such as 0.130 S/cm of proton conductivity at $80^{\circ}C$, 2.324 meq./g-dry-membrane of ion exchange capacity and mechanical characteristics, and 65.03 MPa of tensile strength which were better than Nafion 117 membrane.