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¿µÁøÄÚÆÛ·¹ÀÌ¼Ç Á¾ÇÕÄ«´Ù·Î±× |
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Publication     |
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D. Lerche, T. Sobisch, L.U.M Gmbh, Colloids and Surfaces A : Physicochem. Eng Aspects 440 (2014) 122-130 |
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Introduction     |
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ºÐ»êÇÑ ¹°ÁúÀÇ ºÐ»ê»óÅ (dispersion state) ´Â °øÁ¤ÁßÀÇ Áß°£ »ý¼º¹°ÀÇ Æ¯¼º, ÃÖÁ¾ »ý»êÇ°ÀÇ ±â´ÉÀûÀÎ ¸¹Àº Ư¼º ±×¸®°í Á¦Ç°ÀÇ shelf life ¿¡ Å« ¿µÇâÀ» ¹ÌÄ£´Ù.
ÀÌ°ÍÀº ºÐ»êÇÑ ¹°ÁúÀÌ flocculation, agglutination or agglomeration ±×¸®°í coalescence µîÀÇ Çö»óÀÌ ÀϾ ºÐ»êÇÑ ¹°ÁúÀÌ ¿ø·¡ÀÇ ¸ð½ÀÀ¸·Î µÇµ¹¾Æ °¡´Â Çö»ó
Áï destabilization ÀϾ°Ô µÇ¾î Á¦Ç°ÀÇ Æ¯¼ºÀÌ ¹Ù²î°Ô µÇ±â ¶§¹®ÀÌ´Ù. Flocculation or agglomeration Àº ÀÔÀÚµé »çÀÌÀÇ weak physical interaction ¿¡ ÀÇÇØ
¼·Î ¸ðÀÌ°Ô µÇ´Â °¡¿ªÀû Çö»óÀ¸·Î¼ ¾àÇÑ ±â°èÀûÀÎ ÈûÀ» °¡ÇÏ¿© ÁÖ¸é ÀçºÐ»êÀÌ °¡´ÉÇÏ´Ù.
ÀüÅëÀûÀ¸·Î ºÐ»êÇÑ ¹°ÁúÀÇ ¾ÈÁ¤¼ºÀº ÀÔÀÚÀÇ zeta potential À» ÃøÁ¤ÇÏ¿© ÀÔÀÚ°£ electrostatic interaction À» °è»êÇÏ¿© ºÐ¼®ÇÏ´Â ¹æ¹ýÀ» »ç¿ëÇÏ¿©¿Ô´Ù.
Áï Àý´ëÀû zeta potential °ªÀÌ 10mV ÀÌÇÏÀ̸é flocculation ÀÌ ÀϾ°í 30mV ÀÌÇÏÀÌ¸é ºÐ»ê»óÅ°¡ ºÒ¾ÈÁ¤ÇÏ´Ù´Â °ÍÀ» ÀǹÌÇÏ°í ¡¾30mV À̻󿡼´Â
ºÐ»êÀÌ ¾ÈÁ¤ÇÑ »óÅ·ΠÀÖ´Ù´Â °ÍÀ» ÀǹÌÇÑ´Ù. ±×·¯³ª zeta potential ¿¡ ÀÇÇÑ ºÐ»ê¾ÈÁ¤¼º ºÐ¼®Àº hard sphere ÀÇ particle ¿¡¼¸¸ Àû¿ë °¡´ÉÇÏ´Ù´Â °ÍÀ»
°í·ÁÇÏ¿©¾ß ÇÑ´Ù. ÀÌ·¯ÇÑ hard sphere particle Àº (1) potential ÀÌ ÀÔÀÚ Ç¥¸é¿¡ ÁÖ·Î À§Ä¡ÇØ ÀÖ°í (2) surface conductivity °¡ ¾ø°í (3) ÀÔÀÚÅ©±â¿¡ ºñÇØ ¾ãÀº
diffuse double layer ¸¦ °¡Áö¸ç (4) 3D-surface structure °¡ ¾ø´Â Ư¡ÀÌ ÀÖ´Ù.
³ª³ëºÐ»ê°ú °°Àº formulation ¿¡¼´Â Ç¥¸éÀÇ ±â´É¼º»Ó¸¸ ¾Æ´Ï¶ó steric and entropic stabilization ÀÌ ºÐ»ê¿¡ ´õ Å« ¿µÇâÀ» ¹ÌÄ£´Ù. ÀÌ °æ¿ì ÀÔÀÚ´Â ÁÖ·Î
polyelectrolytes ¶Ç´Â amphoteric surface molecules ·Î ÀÌ·ç¾îÁø ion-permeable surface layer ¿¡ ÀÇÇØ µÑ·¯ ½×¿© ÀÖÀ¸¸ç ÀÌ molecule ÀÇ head group ÀÌ
¿ÜºÎ·Î ÇâÇÏ°í ÀÖ¾î ¹ÙÀÌ¿ÀÀÇ ¼¼Æ÷¿Í À¯»çÇÑ ÇüŸ¦ ¶Ù°íÀÖ´Ù. ÀÌ·± ÇüÅÂÀÇ ÀÔÀÚ¸¦ soft particle À̶ó°í ºÎ¸£´Âµ¥ hard particle °úÀÇ °¡Àå Å« Â÷ÀÌÁ¡Àº
(1) core particle ÁÖÀ§¿¡ fixed electric charges °¡ 3Â÷¿øÀ¸·Î ºÐÆ÷µÇ¾î ÀÖ´Â ÃþÀÌ Ãß°¡·Î Á¸ÀçÇÑ´Ù´Â °ÍÀ̸ç (2) ÀÌ·Î ÀÎÇØ hydrodynamic flow ¿Í
electric conductivity Ư¼ºÀ» °¡Áø´Ù´Â °ÍÀÌ´Ù. ÀÌ·¯ÇÑ ion-penetrable layer ¸¦ particle corona ¶ó ºÎ¸¥´Ù. ÀÌ·¯ÇÑ soft particle ÀÇ zeta potential Àº ½ÇÇèÀû
electrophoretic mobility data ¿¡ ÀÇÇÏ´Â ±âÁ¸ÀÇ zeta potential ÃøÁ¤¹æ½ÄÀ¸·Î´Â ±¸ÇÒ ¼ö ¾øÀ¸¸ç soft particle »çÀÌ¿¡ ÀÛ¿ëÇÏ´Â interaction potential µµ ¿¹ÃøÇÒ ¼ö ¾ø°í
¶ÇÇÑ ºÐ»ê¾ÈÁ¤¼º ¿©ºÎµµ ¿¹ÃøÇÒ ¼ö ¾ø´Â °ÍÀÌ´Ù.
ÀÌ ³í¹®¿¡¼´Â particle-particle interaction À» È®ÀÎÇÏ´Â »õ·Î¿î Á¢±Ù ¹æ¹ýÀÎ analytical
centrifugation (STEP Technology) À» ¼Ò°³ÇÏ°í ºÐ»êÇÑ ¹°ÁúÀÇ phase separation À» È®ÀÎÇϴµ¥ ÀÖ¾î zeta potential °ú ¾î¶² Â÷ÀÌÁ¡ÀÌ ÀÖ´ÂÁö È®ÀÎÇÏ°íÀÚ ÇÑ´Ù.
Hard electronically stabilized particle ÀÇ °æ¿ì¿¡´Â zeta potential ÃøÁ¤¹ý°ú analytical centrifugation ¹æ¹ý ¸ðµÎ µ¿ÀÏÇÑ °á°ú¸¦ º¸¿´À¸³ª soft particle ÀÇ °æ¿ì¿¡´Â
analytical centrifugation ¹æ¹ýÀÌ phase separation À» in situ visualization ÇÒ ¼öÀÖÀ¸¸ç ¶ÇÇÑ flocculation »óŸ¦ Á¤È®È÷ ±¸º°ÇÒ ¼ö ÀÖ¾ú´Ù.
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Analytical centrifugation |
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ºÐ»êÇÑ ¹°ÁúÀ» ÀûÀýÇÑ tube ¿¡ ³Ö°í ȸÀü½ÃÄÑ ¿ø½É·ÂÀ» °¡ÇÏ¸é¼ tube ¿Í ÆòÇàÇÏ¿© Near Infra-red (±ÙÀû¿Ü¼±) ¸¦ Á¶»çÇÏ°í tube ¹Ý´ëÆí¿¡¼ ¾à 2000°³ÀÇ
sensor ·Î¼ Åõ°úµÇ¾îÁö´Â NIR ÀÇ ¾ç (Transmission) À» ÃøÁ¤ÇÏ¿© ±×·¡ÇÁ·Î Ç¥½ÃÇϸé tube Àüü À§Ä¡¿¡¼ ¹°ÁúÀÇ ³óµµ º¯È¸¦ ³ªÅ¸³»´Â Transmission graph ¸¦
±×¸± ¼ö ÀÖ´Ù. Á¤ÇØÁø ½Ã°£º°·Î ¿¬¼ÓÀûÀ¸·Î ÃøÁ¤µÇ¾îÁö´Â ¸ðµç ±×·¡ÇÁ¸¦ ÇϳªÀÇ µµÇ¥¿¡ ³ªÅ¸³»¸é ½Ã°£ÀÇ º¯È¿¡ µû¸¥ transmission ÀÇ º¯È¸¦ ÇÑ´«¿¡ º¼ ¼ö ÀÖ´Â
transmission profile À» ±¸ÇÒ ¼ö ÀÖ´Ù. ÀÌ·± ¹æ¹ýÀ» STEP Technology (Space & Time resolved Extinction Profile) À̶ó Çϴµ¥ ÀÌ ±â¹ýÀ» ÀÌ¿ëÇÏ¸é ¿ø½É·ÂÇÏ¿¡¼
ºÐ»êÇÑ ¹°ÁúÀÇ ¹Ì¼¼ÇÑ phase separation º¯È¸¦ È®ÀÎÇÒ ¼ö ÀÖ´Ù. |
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Example for the classical case of electrostatically stabilized metal oxide dispersion |
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40mV (at pH=5), close to zero (at pH=9) ±×¸®°í below -20mV (at pH=11) ÀÇ zeta potential À» °¡Áö°í ÀÔÀÚÅ©±â´Â 100nm ¿¡¼ 200nm »çÀÌ¿¡ ºÐÆ÷ÇÏ´Â
AEROXIDE Alu C ¸¦ °¢°¢ pH=5, 9, 11 ³óµµ¸¦ °¡Áø ¿ë¾×¿¡¼ ºÐ»ê½ÃÄÑ analytical centrifugation ÇÏ¿© ºÐ»ê»óŸ¦ È®ÀÎÇÏ¿´´Ù (Fig.1).
AEROXIDE Alu C ´Â ´ëÇ¥ÀûÀÎ hard surface particle À̶ó ÇÒ ¼ö ÀÖ´Ù.
Fig.1 ÀÇ a profile Àº pH=5 and ZP=40mV ÇÏ¿¡¼ ÀÔÀÚµéÀº °¢°¢ÀÇ ÀÔÀÚÅ©±â¿¡ µû¶ó °¢±â ´Ù¸¥ ¼Óµµ·Î ÀÏÁ¤ÇÏ°Ô sedimentation ÀÌ ÀϾ´Â °ÍÀ» ¾Ë ¼ö Àִµ¥
¿ø½É·ÂÇÏ¿¡¼ ÀÌ·¯ÇÑ ÇüÅÂÀÇ phase separation ÀÌ ÀϾ´Â °ÍÀº dispersion ÀÌ ¸Å¿ì stable ÇÑ »óÅ¿¡ ÀÖ´Ù´Â °ÍÀ» ÀǹÌÇÏ°í ¶ÇÇÑ ´Ù¾çÇÑ ÀÔÀÚÅ©±â·Î
ÀÌ·ç¾îÁø polydispersion ÀÎ °ÍÀ» ÀǹÌÇÑ´Ù.
Isoelectric point ÀÎ pH=9 Á¶°Ç¿¡¼ ºÐ»êÇÑ ¹°ÁúµéÀº °³º° ÀÔÀÚ°¡ ¾Æ´Ñ flocculation µÇ¾îÁø ÀÔÀÚ ÇüÅ·ΠÁ¸ÀçÇÏ°Ô µÈ´Ù (Fig.1 b.).
Transmission profile ÀÌ ¸Å¿ì °¡Æĸ£°í ¿ìÃøÀ¸·Î °¡¸é¼ profile »çÀÌ °£°ÝÀÌ Á¡Á¡ ´õ Á¼¾ÆÁö´Â °ÍÀ» ¾Ë ¼ö Àִµ¥ ÀÌ´Â flocculation »óÅ·ΠÁ¸ÀçÇÏ´Â ÀÔÀÚµéÀÌ
ħ°ÇÏ¸é¼ ¿ø½É·Â¿¡ ÀÇÇØ compression µÇ¾îÁö±â ¶§¹®ÀÌ´Ù. °á±¹ pH=9 ÇÏ¿¡¼´Â ºÐ»ê ¹°ÁúÀÌ ¸Å¿ì ºÒ¾ÈÁ¤ÇÏ°Ô Á¸ÀçÇÑ´Ù´Â °ÍÀ» ¾Ë ¼ö ÀÖ´Ù.
pH=11 ¿¡¼ Alu C ÀÔÀÚÀÇ zeta potential ÀÌ -20mV ÀÌÇÏ°¡ µÇ´Â ºÐ»ê ¹°ÁúÀÇ analytical centrifugation °á°ú¸¦ º¸¸é (Fig.1 c) Fig.1 a transmission profile °ú´Â
´Ù¸¥ ¸ð½ÀÀ» ¸ðÀÌ°í ÀÖ´Ù.
Fig.1 a ¿¡ ºñÇØ °¢ profile °£ °£°ÝÀÌ Á¶±Ý ´õ ³Ð°í ¿ìÃø¿¡¼ profile ÀÌ compression µÇ´Â °ÍÀ» º¼ ¼ö Àִµ¥ ÀÌ´Â ºÐ»êÇÑ ¹°Áú¿¡ °³º° ÀÔÀÚ¿Í flocculation µÈ
ÀÔÀÚ°¡ µ¿½Ã¿¡ Á¸ÀçÇÑ´Ù´Â °ÍÀ» ÀǹÌÇÑ´Ù.
ÀÌ °á°ú·ÎºÎÅÍ ¿ì¸®´Â zeta potential º¸´Ù analytical centrifugation ÀÌ ºÐ»ê¹°ÁúÀÇ flocculation Çü¼º ¿©ºÎ, sediment packing density µî°ú °°Àº ½ÇÁ¦ÀûÀÎ
Á¤º¸¸¦ ´õ ¸¹ÀÌ Á¦°øÇØÁÖ°í ÀÖ´Ù´Â °ÍÀ» ¾Ë ¼ö ÀÖ´Ù.
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Fig.1. Transmission profiles of AEROXIDE Alu C |
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Example for electrostatically stabilized metal oxide dispersions < 100nm |
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Particle size °¡ 100nm ÀÌÇÏ°¡ µÇ¸é zeta potential value °¡ Å©¸é ºÐ»ê ¹°ÁúÀÇ stability µµ Áõ°¡ÇÑ´Ù´Â »ó°ü°ü°èÀÇ ¿¬°ü¼ºÀÌ ±Þ°ÝÇÏ°Ô ÁÙ¾îµé°Ô µÈ´Ù.
30nm ¿¡¼ 100nm »çÀÌ Å©±âÀÇ ÀÔÀÚ·Î ÀÌ·ç¾îÁø Titania (AEROXIDE P25) ÀÇ zeta potential Àº Fig.2 ¿Í °°À¸¸ç pH 2, 4, 5, 7, 9 ±×¸®°í 10 ¿¡¼ÀÇ
Titania ºÐ»ê¹°ÀÇ analytical centrifugation °á°ú´Â Fig. 3 °ú °°´Ù. pH 2 ¿¡¼´Â 50mV ÀÇ zeta potential ¿¡¼ ¿¹ÃøÇÒ ¼ö ÀÖµíÀÌ ÀÌ ºÐ»ê¹°ÁúÀº ¸Å¿ì
stable ÇÏ¸ç °³º° ÀÔÀÚ Å©±â¿¡ µû¶ó °¢±â ´Ù¸¥ velocity ·Î sedimentation ÀÌ (polydisperse) ÀϾ°í ÀÖ´Ù´Â °ÍÀ» ¾Ë ¼ö ÀÖ´Ù.
¾à 48mV ÀÇ Zeta potential À» °¡Áö´Â pH 4 ¿¡¼µµ stable ÇÑ ºÐ»ê »óŸ¦ ¾Ë ¼ö ÀÖÀ¸³ª pH 2 ¿¡ ºñÇؼ profile °£ °£°ÝÀÌ ´õ ³Ð°Ô ³ªÅ¸³ª´Âµ¥
ÀÌ´Â ºñ·Ï zeta potential Àº pH 2 ¿Í ºñ½ÁÇÑ ¼öÁØÀ̳ª ÀÔÀÚµéÀÌ aggregation µÇ¾î sedimentation ÀÌ ´õ »¡¸® ÀÌ·ç¾îÁö°í ÀÖ´Ù´Â °ÍÀ» ¾Ë ¼ö ÀÖ´Ù.
pH 5 ¿¡¼´Â zeta potential ÀÌ 30mV ·Î ÁÙ¾îµé°Ô µÇÁö¸¸ ¿©ÀüÈ÷ ³ôÀº ¼öÄ¡ÀÌ´Ù. ÇÏÁö¸¸ dispersion state ´Â ¸Å¿ì ºÒ¾ÈÇÏ¿© ÀÔÀÚµéÀÇ flocculation Çü¼ºÀÌ
°ÇÏ°Ô ÀϾ°í ½Ã°£ÀÌ Áö³¯¼ö·Ï flocculation ÀÌ ½ÉÇÏ°Ô compression µÇ´Â °ÍÀ» ¾Ë ¼ö ÀÖ´Ù.
Isoelectric point ÀÎ pH 7 ¿¡¼´Â ´õ Å©°í ´õ »¡¸® sedimentation µÇ´Â flocculation ÀÌ Çü¼º µÇ¾úÀ¸¸ç flocculation network °¡ compression µÇ´Â Çö»óÀº
ÀϾÁö ¾Ê´Â´Ù´Â °ÍÀ» ¾Ë ¼ö ÀÖ´Ù.
Charge °¡ ¹Ù²î¾îÁö´Â pH 9 ¿Í 10 ¿¡¼´Â flocculation network °¡ compression µÇ´Â Çö»óÀÌ ´Ù½Ã ³ªÅ¸³ª°í ƯÈ÷ pH 10 ¿¡¼´Â flocculation µÇÁö ¾ÊÀº
°³º° ÀÔÀÚµéÀÌ sedimentation µÇ°í ÀÖ´Ù´Â °ÍÀ» ¾Ë ¼ö ÀÖ´Ù.
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Enzyme covered silica nanoparticles |
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¿©±â¼´Â ÀüÇüÀûÀÎ soft particle ÀÇ ¿¹¸¦ ¼Ò°³ÇÑ´Ù.
IEP 3 ÀÌ°í ÀÔÀÚ Å©±â°¡ 20nm ÀÎ silica particle À» Á÷°æ 1.9nm, IEP 10.7 ÀÎ lysozyme À¸·Î coating ÇÏ¿´À¸¸ç coated particle ÀÇ pH ¿¡ µû¸¥
zeta potential À» Fig. 4 ¿¡ ³ªÅ¸³»¾ú´Ù.
Plain silica ÀÇ IEP ÀÎ pH 3 À̻󿡼 positively charged lysozyme °úÀÇ »óÈ£ÀÛ¿ë¿¡ ÀÇÇØ pH 6.5 ¿¡¼ zeta potential ÀÌ >20mV ·Î ÃÖ´ë°¡ µÈ´Ù.
pH 4.23, 5.45, 8.68 ±×¸®°í 10.23 ¿¡¼ÀÇ zeta potential Àº °¢°¢ 5, 15, -30 ±×¸®°í -40mV °¡ µÇ¸ç À̶§ÀÇ analytical centrifugation °á°ú¸¦ Fig. 4 ¿¡ ³ªÅ¸³»¾ú´Ù.
Zeta potential ¿ø¸®¿¡ ÀÇÇϸé pH 4 ¿¡¼´Â ³·Àº stability, pH 7 ·Î °¡¸é¼ stability °¡ Áõ°¡ÇÏ°í pH 8.5 ·Î °¡¸é¼´Â ´Ù½Ã stability °¡ °¨¼ÒÇÏ°í pH 9 À̻󿡼´Â
high stability ¸¦ º¸¿©¾ß ÇÑ´Ù. ±×·¯³ª analytical centrifugation °á°ú´Â ¿ÏÀüÈ÷ ´Ù¸¥ ³»¿ëÀ» ¸»ÇÏ°í ÀÖ´Ù.
pH 4.23 ¿¡¼´Â transmission profile ÀÇ º¯È°¡ °ÅÀÇ ¾øÀ¸¸ç ¶ÇÇÑ transmission ÀÌ ¸Å¿ì ³ôÀº °ªÀ¸·Î ³ªÅ¸³ª°í Àִµ¥ ÀÌ´Â 20nm ÀÇ coated silica ÀÔÀÚ°¡
¿ÏÀüÈ÷ °³º°ÀûÀ¸·Î Á¸ÀçÇÏ°í aggregation ÀÌ ¼Ò·®¸¸ ÀϾ°í ÀÖ´Ù´Â °ÍÀ» ÀǹÌÇÑ´Ù. ÀÌ´Â ºñ·Ï zeta potential °ªÀÌ ¸Å¿ì ³·À½¿¡µµ ºÒ±¸ÇÏ°í dispersion ÀÌ
¸Å¿ì stable ÇÏ°Ô Á¸ÀçÇÑ´Ù´Â °ÍÀ» ÀǹÌÇÑ´Ù. pH °¡ 4.23 ¿¡¼ 5.45 ·Î µÇ¸é¼ zeta potential ÀÌ Áõ°¡ÇÏ¿´À½¿¡µµ ºÒ±¸ÇÏ°í dispersion ³»¿¡¼ flocculation ÀÌ
ÀϾ sedimentation ÀÌ È°¹ßÈ÷ ÀϾ°í ÀÖÀ¸¸ç °á±¹Àº dispersion ÀÌ ¸Å¿ì ºÒ¾ÈÁ¤ ÇÏ´Ù´Â °ÍÀ» ¾Ë ¼ö ÀÖ´Ù.
¶ÇÇÑ pH °¡ 8.68 ¿¡¼ zeta potential ÀÌ ¾à -35mV °¡ µÇ¾úÀ½¿¡µµ ºÒ±¸ÇÏ°í zeta potential ÀÌ ¾à 15mV ÀÎ pH 5.45 ¿¡¼ º¸´Ù dispersion stability °¡ ÈξÀ
´õ °¨¼ÒÇß´Ù´Â °ÍÀ» ¾Ë ¼ö ÀÖ´Ù.
pH 10.23 ÀÎ Á¶°Ç¿¡¼´Â ÀÔÀÚµé »çÀÌÀÇ interaction ÀÌ °¨¼ÒÇØ flocculation Çü¼ºÀÌ ÁÙ¾îµé¾î ´Ù¼Ò ¾ÈÁ¤ÀûÀÎ ºÐ»ê »óŸ¦ À¯ÁöÇÑ´Ù´Â °ÍÀ» ¾Ë ¼ö ÀÖ´Ù.
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Polyelectrolyte coated magnetic nanoparticles for gene delivery |
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Polyelectrolyte ·Î coating µÈ core-shell type silica/iron oxide magnetic nanoparticles ´Â ¸Å¿ì º¹ÀâÇÑ ±¸Á¶¸¦ °¡Áö°í ÀÖ´Ù.
Surface phosphate group °ú polyelectrolyte ¸¦ °¡Áø silicon dioxide °¡ layer ¸¦ Çü¼ºÇϸç magnetic core ¸¦ µÑ·¯ ½Î°í ÀÖ´Ù.
ÀÌ·¯ÇÑ ±¸Á¶¿¡ ÀÇÇØ ÀüÇüÀûÀÎ two-dimensional surface charge distribution ÀÌ ¾Æ´Ñ ƯÀÌÇÑ spatial fixed charge distribution ±¸Á¶°¡ µÈ´Ù.
Dispersion ¿¡¼ ÀÌ·¯ÇÑ polyelectrolyte µéÀÌ flocculation À» Çü¼ºÇÏ´Â °úÁ¤Àº ¸Å¿ì º¹ÀâÇÏ´Ù.
Negatively charged silica-iron oxide magnetic nano particle À» positively charged polyethylene Imine (PEI) À¸·Î PEI / iron (%m/m) À¸·Î Á¤·®ÀûÀ¸·Î coating
ÇÏ°Ô µÇ¸é particle ÀÇ charge °¡ º¯ÇÏ°í zeta potential µµ Fig. 5 ¿¡ º¸¿©ÁÖµíÀÌ undecorated particles (SO-Mag5) -38¡¾2 mV ¿¡¼ºÎÅÍ SO-Nag6-5
¾à 40mV ±îÁö ´Ù¾çÇÏ°Ô º¯ÇÏ°Ô µÈ´Ù.
ÀÌ °æ¿ì zeta potential Àº dispersion ¿¡ ¿µÇâÀ» ¹ÌÄ¡Áö ¾Ê°í iron ´ç PEI ³óµµ°¡ 10%, 12% ÀÏ ¶§ °¡Àå ÀûÀýÇÑ dispersion À» ±¸ÇÒ ¼ö ÀÖ´Ù.
PEI decoration ¿¡ ´ëÇÑ dispersion ÀÇ stability ¸¦ Analytical centrifuge ¸¦ ÀÌ¿ëÇÏ¿© ºÐ¼®ÇÏ¿´´Ù (Fig. 6)
PEI ¸¦ ÷°¡ÇÏÁö ¾ÊÀº undecorated SO-Mag5 ÀÇ °æ¿ì (Fig. 6, 0¹ø graph) º¯È°¡ °ÅÀÇ ¾øÀ» Á¤µµ·Î ¸Å¿ì stable ÇÑ dispersion ÀÓÀ» ¾Ë ¼ö ÀÖ´Ù.
1% ÀÇ PEI ¸¦ ÷°¡ÇÑ °æ¿ì (Fig. 6, 1¹ø graph) net negative charge °¡ ´Ù¼Ò °¨¼ÒÇÏ¿´À¸³ª dispersion »óÅ°¡ ¸¹ÀÌ º¯ÇÏ¿´´Ù. Áï °³º° ÀÔÀÚµéÀÌ
sedimentation ÇÏ´Ù°¡ ÀÔÀÚ»çÀÌ¿¡ flocculation ÀÌ Çü¼ºµÇ¾î ÀÔÀÚ°¡ ÇѲ¨¹ø¿¡ ¶³¾îÁö´Â Çü»óÀ» º¸ÀδÙ. 2% ÀÇ PEI ¸¦ ÷°¡ÇÑ °æ¿ì (Fig. 6, 2¹ø graph) °³º° ÀÔÀÚÀÇ
À̵¿Àº º¸ÀÌÁö ¾Ê°í °ÅÀÇ ÀüºÎ°¡ flocculation µÇ¾î network Çü½ÄÀ¸·Î sedimentation µÇ¾î compression µÇ´Â zone sedimentation Çü»óÀÌ ³ªÅ¸³´Ù.
2% ÀÇ PEI ¸¦ ÷°¡ÇÑ °æ¿ì (Fig. 6, 2¹ø graph) sedimentation pattern ÀÌ ´Ù½Ã º¯Çϴµ¥ ƯÀÌÇÏ°Ôµµ µÎ °¡Áö Á¾·ùÀÇ ÀÔÀÚ°¡ sedimentation ÇÏ´Â bimodal separation °ú
À¯»çÇÑ ÇüŸ¦ ³ªÅ¸³»°í ÀÖ´Ù. Áï Ãʱ⿡´Â ´Ù¾çÇÑ Å©±âÀÇ ÀÔÀÚµéÀÌ °³º°ÀûÀ¸·Î sedimentation ÇÏ´Â ÇüŸ¦ º¸ÀÌ´Ù°¡ °úÁ¤ÀÌ ÁøÇàÇÔ¿¡ µû¶ó zeta potential ÀÌ
30mV ÀÌ»óÀÓ¿¡µµ ºÒ±¸ÇÏ°í °³º°ÀÔÀÚµéÀÌ ´Ù½Ã »óÈ£ÀÛ¿ëÇÏ¿© flocculation network ¸¦ Çü¼ºÇÏ¿© ¸ðµÎ °°ÀÌ ¶³¾îÁö´Â zone sedimentation ¸ð½ÀÀ» º¸ÀÌ°í ÀÖ´Ù.
PEI-loading ¾çÀ» ´õ¿í ´Ã·Á ÃÑ 12% ±îÁö PEI ¾çÀ» Áõ°¡½ÃÄѵµ (Fig. 6, 12¹ø graph) zeta potential Àº ÀÏÁ¤ÇÏ°Ô 40mV ¸¦ À¯ÁöÇϴµ¥ flocculation Àº ÀϾÁö ¾Ê°í
ÀüüÀûÀ¸·Î polydisperse ÇüŸ¦ ³ªÅ¸³»¾î ¸Å¿ì ¾ÈÁ¤ÇÑ dispersion À» À¯ÁöÇÏ°í ÀÖ´Ù.
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Conclusion |
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ÀÚ¿¬Áß·Â ¶Ç´Â ¿ø½É·Â ÇÏ¿¡¼ dispersion ÀÇ separation µÇ´Â °ÍÀ» °üÂûÇϸé particle surface alteration, particle agglomeration/flocculation
±×¸®°í colloidal stability ¿¡ ´ëÇÑ Á¤º¸¸¦ Á÷Á¢À¸·Î È®ÀÎÇÒ ¼ö ÀÖ´Ù. ±×¸®°í dispersion state ¸¦ Á¤·®È ÇÒ ¼ö ÀÖÀ¸¸ç formulation À» ÃÖÀûÈ ÇÒ ¼ö ÀÖ´Ù.
ÀüÅëÀû ¹æ¹ýÀ¸·Î ÃøÁ¤µÈ zeta potential Àº agglomeration/flocculation À» Á¤È®ÇÏ°Ô ¹Ý¿µÇÏÁö ¸øÇÏ°í ƯÈ÷ soft particle ÀÇ °æ¿ì zeta potential °ªÀÌ
ÃæºÐÈ÷ Å«µ¥µµ ºÒ±¸ÇÏ°í flocculation µÉ ¼ö ÀÖ´Ù.
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