The authors would like to acknowledge the support from the Department of Earth Sciences, Uppsala University for supporting part of this research.

다중 벽 탄소 나노 튜브의 1 기능화 <ol><li> 안전 안경, 장갑 및 실험실 코트를 사용하여, 흄 후드 내부의 전체 작용 단계를 수행합니다. 눈금 실린더를 사용하여 질산 산성 황산 24 ㎖를 8 mL로 측정 한 다음 비이커로 옮긴다. 분석 저울에 주석 호일 컨테이너를 사용하여 비커에 처리되지 않은 다중 벽 탄소 나노 튜브의 32 mg을 추가 (최종 농도는 1 ㎎ / 산 혼합물의 ml를해야한다). </li><li> 첫째, 실온에서 2 시간 동안 초음파 세척기 (목욕)에 MWCNT 산 혼합물 비커를 유지. 그런 다음, 열 및 90에서 5 시간 동안 MWCNT-산 용액을 저어 핫 플레이트를 사용하여 ° C. </li><li> 필터 홀더에 배치 0.2 μm의 세공 직경의 PTFE 멤브레인 필터로 CNT 현탁액을 여과하고 여과를 돕기 위해 진공을 사용한다. 부분에 의해 여과 부분을 수행하고 여러 필터 멤브레인 (하나의 필터에 대한 부분마다 상기 혼합물의 약 1/4 일)를 사용합니다. 끓는 물에 추가혼합물의 pH가 5보다 커질 때까지 여과 공정시에 산 용액을 걸러. </li><li> 이 꺼져 있고 진공 시스템에 아무것도를 소개하지 전에 항상를 주입합니다. 폐액 수집 비커를 사용한다. </li><li> 폐기물 용기에 붓고 여과 산 (폐기물 처리 시설로 폐기물 용기를 보내거나 수돗물 중 적어도 열 배를 가산함으로써 싱크로 덤핑 전에 액체 희석). </li><li> CNT (약 24 시간 건조를 완료하기 위해 음식을 증발로 유지 다중 벽 탄소 나노 튜브와 여과막을 전송하고, 데시 케이 터에 넣어 요리 (실리카겔 약 100g 함유) 및 진공 환경을 생성 (약 1 시간 동안 진공을두고) ). <ol><li> 주걱을 사용하여 조심스럽게 막에서 탄소 나노 튜브를 긁어 깨끗한 용기 내로 입자를 옮긴다. 다중 벽 탄소 나노 튜브 분말의 무게를 측정하고 향후 사용을 위해 컨테이너를 레이블을 붙입니다. </li></ol></li></ol> 2. Poro전송 실험에 대한 우리 미디어 <ol><li> 실리카 모래의 산 세척 0.1 M HCl 용액을 준비합니다. <ol><li> 안전 안경, 장갑, 실험실 코트와 흄 후드 내부의 모든 단계를 수행합니다. 2 L 플라스크에 1 L를 탈 이온수를 추가합니다. 눈금 실린더를 사용하여 37 % 염산 8 mL로 측정한다. </li><li> 조심스럽게 탈 이온수에 염산을 추가합니다. 혼합하기 위해 조심스럽게 플라스크를 흔들어. </li></ol></li><li> 준비된 HCl 용액으로 모래를 씻으십시오. <ol><li> 약 1,000g 모래의 무게를. HCl 용액과 플라스크에 모래의 1/3를 추가하고 모래 (모래마다의 1/3)의 나머지 부분을 추가 한 후 혼합하기 위해 두 번 플라스크를 흔들어. </li><li> 플라스크를 세 번 흔들어 30 분간 모래 산을 둡니다. </li><li> 적어도 8 배를 산 폐액 용기 플라스크에서 액체를 붓고 탈 이온수로 모래를 씻어. </li></ol></li><li> H 2 O 2 용액으로 모래를 씻으십시오. <ol><li> 에 탈 이온수 700 ml에 추가모래 플라스크는 눈금 실린더를 사용하여 2 O 2 30 % 용액 40㎖의 H를 측정한다. </li><li> 모래 플라스크에 H 2 O 2 솔루션을 추가하고 혼합하기 위해 두 번 흔들어. 플라스크에 160 ml의 H 2 O 2 총이 때까지 2 O 2 용액을 3 회 30 % H의 또 다른 (40)를 가하여. </li><li> 흔들어 용액과 모래 매번 혼합하고, 반응이 완료 될 수 있도록 40 ​​분 동안 모래 H 2 O 2 용액을 떠난다. 플라스크를 흔들어 플라스틱 막대 매 10 분에 모래를 저어. </li><li> 싱크대 아래로 액체를 가만히 따르다 30 초 동안 수돗물을 실행합니다. </li></ol></li><li> 씻어 모래를 건조. <ol><li> 탈 이온수와 모래를 씻어 최소 8 시간은 모든 솔루션 제거 또는 반응 생성물을 통해 버려지합니다. 흔들어 세척 할 때 철저하게 약동하십시오. </li><li> 건조 24 시간 동안 오븐 (105 ° C)로 세척 모래 플라스크에 넣고, 다음 사용하여 오븐에서 모래를 취할모래가 식을 때까지 오븐 벙어리 장갑 2 시간 동안 카운터에 둡니다. </li><li> 플라스틱 용기에 깨끗한 모래를 전송합니다. 컨테이너를 표시하고 사용하기위한 준비를 적절한 선반에 배치합니다. </li></ol></li></ol> 3. 열 실험 <ol><li> 배경 용액의 조제. <ol><li> 열 실험에 적합한 배경 솔루션 화학을 준비합니다. </li><li> 다음 실험에 적합한 이온 강도를 달성하기 위해 pH 및 염화나트륨 염을 조정할 0.1 M HCl 및 0.1 M의 NaOH 용액을 사용한다. </li></ol></li><li> 열 선택. <ol><li> 이 실험 (5 및 이온 강도 : 본 연구에서 2 mM의 산도) 2.5 cm 직경 15cm 길이의 유리 열을 선택합니다. 유리관의 양쪽에있는 스틸 메쉬 필터 (0.2 mm)를 사용합니다. </li><li> 컬럼에 연결된 튜브 플러시 및 액체 흐름의 유형을 제어하기 위해 3- 방향 밸브까지 배경 용액으로 기입 (또는 다중 벽 탄소 나노 튜브 용액 (다중 벽 탄소 나노 튜브의 solution 또는 배경 용액)도 1에 도시 된 바와 같이. </li></ol></li><li> 컬럼의 습식 포장. <ol><li> 규모에 깨끗한 모래의 무게를 측정하고 선택한 열 크기 깨끗한 모래 124g을. </li><li> 높은 정밀도 연동 펌프를 사용합니다. 액체 유동의 2 ml / 분을 달성하기 펌프를 보정. </li><li> 수위가 증류탑의 저부 위의 몇 센티미터 때까지 아래로부터 열을 채우기 위해 펌프를 켜고. 열에 한번에 측정 모래의 약 1/10을 넣어하지만 모래 레벨이 열에있는 수위 위에 오지 않는지 확인. 모래 수준 이상으로 유지하기 위해 계속 열로 물 흐름을 계속합니다. </li><li> 완전 충전 후 적절한 필터 메쉬 열 뚜껑을 닫습니다. </li><li> 충전 탑은 적어도 1 시간 동안 흐르게. 칼럼의 개개의 파라미터는 다음 표 1에 나타내었다. </li></ol></li><li> 트레이서 시험. <ol><li> 에스MWCNT 솔루션 실험 이전에 추적 테스트와 열 실험을 타트. </li><li> 실험을 시작하기 위해 (20 ㎎ / L로 음식 색 트레이서를 사용하여) 트레이서 용액에 3 방향 전환 밸브. </li><li> 매 2 분에서 컬럼으로부터 유출을 채취 (즉, 4 ㎖ / 각 샘플링 튜브 내의 샘플)도 1에 도시 된 바와 같이 연결된 분획 수집기를 사용. </li><li> 4.32 세공 용적에 대한 트레이서 용액을 주입 계속 또한 실험의 위상을 I라고 (즉, 용액 모래 충전 탑의 총 세공 빈 공간을 통과 4.32 배). </li><li> 다른 기공 부피 4.32 대 (트레이서 실험의 경우 DI 물) 배경 용액 흐르도록 3 방향 전환 밸브. </li></ol></li><li> 다중 벽 탄소 나노 튜브 용액의 조제. <ol><li> 원하는 solutio로 (수용액 200 ㎖을 함유하는 300 ml의 비이커에 기능화 된 다중 벽 탄소 나노 튜브 15mg의 배치하여 분산, 기능화 된 다중 벽 탄소 나노 튜브 용액을 만들기N 화학 즉, pH가 5 및 2 mM의 이온 전류 실험 조건에서의 강도)과 15 분 동안 40 %의 출력되는 동력을 비커에 넣고 초음파 프로브를 호 모지 나이저 (사용). 15 ㎎ / L의 농도를 달성 MWCNT 동일한 수용액 800 mL를 다른 다중 벽 탄소 나노 튜브 분산 용액을 섞는다. </li><li> 크기와 후 기능화 된 나노 입자의 형상에 대한 스톡 용액의 주사 전자 현미경 (SEM) 이미지 분석을 수행한다. </li></ol></li><li> MWCNT 전송 실험. <ol><li> 열 실험을 시작 MWCNT 용액에 3 방향 전환 밸브. </li><li> 연결된 부분 수집기를 사용하여 매 2 분의 열에서 유출 샘플을 수집합니다. </li><li> 4.32 기공 부피 대 용액 MWCNT (I 실험의 위상)을 주입한다. </li><li> 실험의 단계 II라고 다른 세공 용적 4.32, 배경 용액을 흐르게 3 방향 전환 밸브. </li><li> backgro에의 주입 관 변경상기 실험의 위상 III라고 다른 4.32 세공 용적에 대한 흐름을 계속 (튜브에서 공기의 입구를 피하기 위해 잠시 동안 펌프를 정지 한 후) DI 물 병으로 싶게 용액. </li></ol></li><li> 샘플 분석. <ol><li> 튜브 랙에 분수 집에서 모든 튜브 샘플을 전송합니다. </li><li> , 시료 분석, 즉를위한 UV / VIS 분광 광도계를 준비 수집 된 시료의 정량에 대한 적절한 검사 파장을 찾을 수 있습니다. MWCNT 솔루션 및 추적 솔루션을위한 333 nm 파장 400 nm의를 사용합니다. </li><li> I, II, 및 (이전 단계에서 더 적합하다고 판단하는 경우 또는 상이한 파장) 400 nm의 파장을 사용하는 큐벳 III 및 데이터를 저장하는 단계 동안 컬럼으로부터 수집 된 모든 샘플을 스캔. </li><li> 분광 광도계로부터 데이터를 수집하고 대표적인 결과에 나타낸 바와 같이 (예를 들면, 파과 곡선을 얻기 위해 시간 또는 세공 용적 대 그리면,도3). </li><li> 제타 사이 저를 이용하여 유입 및 유출 샘플의 크기 분석 (수력 학적 직경)을 수행하고, 주사 전자 현미경을 사용하여 두 유출입 샘플에 대한 연구를 수행 시각화. </li></ol></li></ol>

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Technol. 45 (22), 9765-9775 (2011).</li><li>Kasel, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Limited+transport+of+functionlized+multi-walled+carbon+nanotubes+in+two+natural+soils.">Limited transport of functionlized multi-walled carbon nanotubes in two natural soils.</a> Environ. Pollution. 180, 152-158 (2013).</li><li>Yu, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+humic+acid+and+Tween-80+on+behavior+of+decabromodiphenyl+ether+in+soil+columns.">Effects of humic acid and Tween-80 on behavior of decabromodiphenyl ether in soil columns.</a> Environ. Earth Sci. 69 (5), 1523-1528 (2013).</li><li>Jaisi, D. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transport+of+single-walled+carbon+nanotubes+in+porous+media:+filtration+mechanisms+and+reversibility.">Transport of single-walled carbon nanotubes in porous media: filtration mechanisms and reversibility.</a> Environ. Sci. Technol. 42 (22), 8317-8323 (2008).</li><li>Tiraferri, A., Tosco, T., Sethi, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transport+and+retention+of+microparticles+in+packed+sand+columns+at+low+and+intermediate+ionic+strengths:+experiments+and+mathematical+modeling.">Transport and retention of microparticles in packed sand columns at low and intermediate ionic strengths: experiments and mathematical modeling.</a> Environ. Earth Sci. 63 (4), 847-859 (2011).</li><li>Tian, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deposition+and+transport+of+functionalized+carbon+nanotubes+in+water-saturated+sand+columns.">Deposition and transport of functionalized carbon nanotubes in water-saturated sand columns.</a> J. Hazard. Mater. 213-214, 265-272 (2012).</li><li>Mekonen, A., Sharma, P., Fagerlund, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transport+and+mobilization+of+multiwall+carbon+nanotubes+in+quartz+sand+under+varying+saturation.">Transport and mobilization of multiwall carbon nanotubes in quartz sand under varying saturation.</a> Environ. Earth Sci. 71 (8), 3751-3760 (2014).</li><li>Sharma, P., Bao, D., Fagerlund, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deposition+and+mobilization+of+functionalized+multiwall+carbon+nanotubes+in+saturated+porous+media:+effect+of+grain+size,+flow+velocity+and+solution+chemistry.">Deposition and mobilization of functionalized multiwall carbon nanotubes in saturated porous media: effect of grain size, flow velocity and solution chemistry.</a> Environ. Earth Sci. , (2014).</li><li>Phenrat, T., Lowry, G. V., Hotze, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoparticle+aggregation:+challenges+to+understanding+transport+and+reactivity+in+the+environment.">Nanoparticle aggregation: challenges to understanding transport and reactivity in the environment.</a> J. Environ. Qual. 39 (6), 1909-1924 (2010).</li><li>Crist, J. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transport+and+retention+mechanisms+of+colloids+in+partially+saturated+porous+media.">Transport and retention mechanisms of colloids in partially saturated porous media.</a> Vadose Zone J. 4 (1), 184-195 (2005).</li><li>Jaisi, D. P., Elimelech, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-walled+carbon+nanotubes+exhibit+limited+transport+in+soil+columns.">Single-walled carbon nanotubes exhibit limited transport in soil columns.</a> Environ. Sci. Technol. 43 (24), 9161-9166 (2009).</li><li>Corapcioglu, M. Y., Choi, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+colloid+transport+in+unsaturated+porous+media+and+validation+with+laboratory+column+data.">Modeling colloid transport in unsaturated porous media and validation with laboratory column data.</a> Water Resour. Res. 32 (12), 3437-3449 (1996).</li><li>Wan, J., Wilson, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Colloid+transport+in+unsaturated+porous+media.">Colloid transport in unsaturated porous media.</a> Water Resour. Res. 30 (4), 857-864 (1994).</li><li>Wan, J., Wilson, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visualization+of+the+role+of+the+gas-water+interface+on+the+fate+and+transport+of+colloids+in+porous+media.">Visualization of the role of the gas-water interface on the fate and transport of colloids in porous media.</a> Water Resour. Res. 30 (1), 11-24 (1994).</li><li>Bradford, S. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physical+factors+affecting+the+transport+and+fate+of+colloids+in+saturated+porous+media.">Physical factors affecting the transport and fate of colloids in saturated porous media.</a> Water Resour. Res. 38 (12), (2002).</li><li>Bradford, S. A., Torkzaban, S., Walker, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coupling+of+physical+and+chemical+mechanisms+of+colloid+straining+in+saturated+porous+media.">Coupling of physical and chemical mechanisms of colloid straining in saturated porous media.</a> Water Res. 41 (13), 3012-3024 (2007).</li></ol>

The authors declare that they have no competing financial interests.

다중 벽 탄소 나노 튜브 기능화의 효과 도 2는 작용 화 된 다중 벽 탄소 나노 튜브의 안정성이 확인 된 바와 같이, MWCNT의 용출 부피에서 관측 된 차이는 다중 벽 탄소 나노 튜브의 표면 (-COOH) 그룹에 의한 작용 및 카르복실기의 첨가 특히 때문이었다 (도 3 및도 4). 유사한 작용 화 공정에서 산소의 존재는 X 선 광전자 분광법에 의해 확인 하...

정보 기술, 에너지, 환경 과학, 의학, 국토 안보, 식품 안전 및 수송 등의 산업 분야에서 많은 기술을 개선하기 위해 다양한 종류의 나노 입자를 사용하는 나노 기술의 최근 발전과 함께; 토양 및 지하수의 나노 입자의 수송 및 유지에 대한 철저한 이해를 위해 평가뿐만 아니라 나노 입자 설계 1-3의 환경 응용에 중요하다. 탄소 나노 튜브는 대부분의 제조 된 탄소 계 나노 입자 2,4- 중 하나이다. 탄소 나노 튜브는 일반적으로 100 나노 미터 이하의 직경이 50 ㎛ 인 100 nm 범위의 길이를 갖는 그라 펜 길고 원통형이다. 그들은 전자, 광학, 화장품, 생물 의학 기술 (예를 들어, 복합 재료) (5)와 같은 많은 응용 프로그램에서 사용을 가속화 독특한 특성을 보유하고 있습니다. 사용 증가로, 또한 증가 R이인체 노출 및 효과 건강에뿐만 아니라 CNT 및 환경 5-8 다른 탄소 기반 나노 물질 처리 다음과 생태계에 부정적인 영향을 ISK. 지표면 변형 (비관 능화 된)로, 탄소 나노 튜브는 매우 소수성이며 수용액에 응집하는 경향이있다. 기능화 된 탄소 나노 튜브는, 그러나, 분산 수용액에서 안정하고 이러한 약물 전달 9 생물 의학적 용도로 사용된다 남아있을 수있다. 여기에서는 탄소 나노 튜브가 분산 동원 때문에 약물이 인체 (10) 내에 전달 될 ​​수있는 상태로 유지하는 것이 필수적이다. 한편, 환경 위험을 줄이기 위해, 대수층 및 식수 자원 (11)에 그 입구를 방지하기 위해 탄소 나노 튜브를 고정화하는 방법을 중심으로 연구가 필요하다. 최근의 연구는 살아있는 유기체에 탄소 나노 튜브의 독성 효과를보고도 있기 때문에, 입력하고 먹이 사슬에 축적 탄소 나노 튜브의 관점에서 생태계에 위험했다5,8를 생분해 탄소 나노 튜브는 어렵다. 탄소 나노 튜브의 장벽을 통과하기 위해 탄소 나노 튜브를 함유해도 매립 배리어 시스템을 가진 것이 가능할 수있다. 이러한 경우 탄소 나노 튜브는 지하수 저수지 및 표면 수역에 입력 할 수 있습니다. CNT의 폐기 규정이 잘 정의되지 않고 반송기구가 제대로 이해되는 바와 같이, 탄소 나노 튜브의 이동도의 개선 된 이해를 공식화 및 디자인 적절한 폐기 시스템 (12)에 필요하다. 따라서 CNT 보유를 수정 운명과 다공성 매체에서 탄소 나노 튜브의 수송 및 표면에 지하 환경에 일반적으로 존재하는 물리적, 화학적 요인의 효과를 연구하고 이해하는 것이 중요합니다. 다수의 연구는 다공성 매질에서의 나노 입자의 수송에 입자 (17)의 속도 (16), 및 표면 특성, 유동 콜렉터 입경 13-15의 효과에 대해 수행되었다. 오디오 솔루션의 효과에 그러나 체계적인 조사콜렉터 표면 상으로 가능한 증착에 이온 화학 (예 : pH와 이온 강도 등)는 여전히 18 ~ 20를 제한됩니다. 또한, 물리적 요인, 매체의 솔루션 화학, 탄소 나노 튜브의 표면 특성의 결합에 미치는 영향을 잘 이해하고 다른 문헌에서 변화되지 않습니다. 본 연구에서 다중 벽 탄소 나노 튜브의 표면 개질에 대한 제조 방법은, 산 세정 석영 모래를 충전 체계적인 실험실 규모의 컬럼과 함께 설명 될 것이다하는 포화 된 다공성 지지체의 표면 개질 된 탄소 나노 튜브의 반송, 유지 및 재 이동을 조사하기 위해 사용되는 .

<table border="0" cellpadding="0" cellspacing="0" width="750">
	<tbody>
		<tr height="43">
			<td height="43" style="height:43px;width:183px;">Name of Material/ Equipments</td>
			<td style="width:228px;">Company</td>
			<td style="width:169px;">Catalog Number</td>
			<td style="width:171px;">Comments/Description</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:183px;">MWCNT</td>
			<td style="width:228px;">Cheap Tubes Inc., USA</td>
			<td style="width:169px;">sku-03040304</td>
			<td style="width:171px;">Purchased as semi-functionlized powder</td>
		</tr>
		<tr height="148">
			<td height="148" style="height:148px;width:183px;">Quartz sand</td>
			<td style="width:228px;">Sibelco Nordic, Baskarp, Sweden</td>
			<td style="width:169px;">B44</td>
			<td style="width:171px;">Purchased with more than 91% silica sand</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:183px;">H2SO4</td>
			<td style="width:228px;">VWR</td>
			<td style="width:169px;">1.01833.2500</td>
			<td style="width:171px;">95-97% purity</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:183px;">HNO3</td>
			<td style="width:228px;">VWR</td>
			<td style="width:169px;">1.00441.1000</td>
			<td style="width:171px;">70% purity</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:183px;">HCl</td>
			<td style="width:228px;">VWR</td>
			<td style="width:169px;">1.00317.2500</td>
			<td style="width:171px;">37-38% purity</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:183px;">H2O2</td>
			<td style="width:228px;">VWR</td>
			<td style="width:169px;">23615.248</td>
			<td style="width:171px;">30% purity</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:183px;">NaCl</td>
			<td style="width:228px;">VWR</td>
			<td style="width:169px;">1.06404.0500</td>
			<td style="width:171px;">99.5% purity</td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:183px;">NaOH</td>
			<td style="width:228px;">Sigma-Aldrich</td>
			<td style="width:169px;">S8045-500G</td>
			<td style="width:171px;">99.99% pur pellets&#160;</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:183px;">Ultrasonic Homogenizer</td>
			<td style="width:228px;">Biologics Inc. Manassas, Virginia</td>
			<td style="width:169px;">Model 3000, 0-127-0002</td>
			<td style="width:171px;">Operated for fix time interval</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:183px;">Sonicator (bath)</td>
			<td style="width:228px;">Kerry Ultrasonic Ltd</td>
			<td style="width:169px;">1808</td>
			<td style="width:171px;">Common bath sonicator</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:183px;">Peristaltic pump</td>
			<td style="width:228px;">Ismantec, Glattbrugg, Switzerland</td>
			<td style="width:169px;">ISM931</td>
			<td style="width:171px;">Work with tygon tubing in the pump</td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:183px;">Spectrophotometer</td>
			<td style="width:228px;">Hach Lange</td>
			<td style="width:169px;">DR500, LPV408.99.0001</td>
			<td style="width:171px;">Operate with manual cuvette as well as automated sampling</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:183px;">pH meter</td>
			<td style="width:228px;">Metrohm</td>
			<td style="width:169px;">781</td>
			<td style="width:171px;">pH analysis</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:183px;">Glass column</td>
			<td style="width:228px;">Chromaflex</td>
			<td style="width:169px;">420830-1510</td>
			<td style="width:171px;">Column with adjustable cap</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:183px;">Fraction collector</td>
			<td style="width:228px;">Spectrum Labs Europe</td>
			<td style="width:169px;">CF-2, 124846</td>
			<td style="width:171px;">Fixed at regular interval of time</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:183px;">Fraction collector tubes</td>
			<td style="width:228px;">VWR</td>
			<td style="width:169px;">212-9599</td>
			<td style="width:171px;">6 ml volume glass tube</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:183px;">Hot plate stir</td>
			<td style="width:228px;">Thermo Scientific</td>
			<td style="width:169px;">SP131320-33</td>
			<td style="width:171px;">Adjustable tempurature</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:183px;">Oven</td>
			<td style="width:228px;">Elektro Helios</td>
			<td style="width:169px;">259</td>
			<td style="width:171px;">For oven dry of sand</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:183px;">Balance</td>
			<td style="width:228px;">Mettler Toledo</td>
			<td style="width:169px;">AE 160</td>
			<td style="width:171px;">For accurate weight</td>
		</tr>
	</tbody>
</table>

transport of surface-modified carbon nanotubes through a soil column

Carbon nanotubes (CNTs) are widely manufactured nanoparticles, which are being utilized in a number of consumer products, such as sporting goods, electronics and biomedical applications. Due to their accelerating production and use, CNTs constitute a potential environmental risk if they are released to soil and groundwater systems. It is therefore essential to improve the current understanding of environmental fate and transport of CNTs. The transport and retention of CNTs in both natural and artificial media have been reported in literature, but the findings widely vary and are thus not conclusive. There are a number of physical and chemical parameters responsible for variation in retention and transport. In this study, a complete procedure of selected multiwalled carbon nanotubes (MWCNTs) is presented starting from their surface modification to a complete set of laboratory column experiments at critical physical and chemical scenarios. Results indicate that the stability of the commercially available MWCNTs are critical with their attached surface functional group which can also influence the transport and retention of MWCNT through the surrounding medium.

다중 벽 탄소 나노 튜브 기능화의 효과 기능화 MWCNT 분산 용액 용액 평형에 도달 할 수 있도록 비이커에 밀봉 하였다. 초음파 6 개월 (그림 2)에 대한 동일하게 유지 솔루션 MWCNT의 유체 역학적 직경 (1,619 ± 262 ㎚)로 초음파 처리 후 원액에서 관찰도 침강이나 응집이 있었다. 이동성에 다중 벽 탄소 나노 튜브의 작용의 효과를 조사하기 위해, 열 실험의 ?...

Watch this Scientific Journal Video about Transport of Surface-modified Carbon Nanotubes through a Soil Column at JoVE.com

Transport of Surface-modified Carbon Nanotubes through a Soil Column

Surface properties of a nanoparticle are important for their interaction with the surrounding medium. Therefore the surface modification of carbon nanotubes can be critical for their transport and retention through porous media. Here, lab scale column experiments are used to understand the possible transport and retention of these nanoparticles.

토양 칼럼을 통해 표면 개질 된 카본 나노 튜브의 운송

Carbon nanotubes (CNTs) are widely manufactured nanoparticles, which are being utilized in a number of consumer products, such as sporting goods, ...

transport-of-surface-modified-carbon-nanotubes-through-a-soil-column

Research

JoVE Journal

Chemistry

9.4K 조회수.  Nalanda University. Surface properties of a nanoparticle are important for their interaction with the surrounding medium. Therefore the surface modification of carbon nanotubes can be critical for their transport and retention through porous media. Here, lab scale column experiments are used to understand the possible transport and retention of these nanoparticles. 

비디오: Transport of Surface-modified Carbon Nanotubes through a Soil Column

Dependence of Laser-induced Breakdown Spectroscopy Results on Pulse Energies and Timing Parameters Using Soil Simulants

The dependence of some LIBS detection capabilities on lower pulse energies (&lt;100 mJ) and timing parameters were examined using synthetic silicate samples. These samples were used as simulants for soil and contained minor and trace elements commonly found in soil at a wide range of concentrations. For this study, over 100 calibration curves were prepared using different pulse energies and timing parameters; detection limits and sensitivities were determined from the calibration curves. Plasma temperatures were also measured using Boltzmann plots for the various energies and the timing parameters tested. The electron density of the plasma was calculated using the full-width half maximum (FWHM) of the hydrogen line at 656.5 nm over the energies tested. Overall, the results indicate that the use of lower pulse energies and non-gated detection do not seriously compromise the analytical results. These results are very relevant to the design of field- and person-portable LIBS instruments.

LIBS detection capabilities on soil simulants were tested using a range of pulse energies and timing parameters. Calibration curves were used to determine detection limits and sensitivities for different parameters. Generally, the results showed that there was not a significant reduction in detection capabilities using lower pulse energies and non-gated detection.

토양 닮은를 사용하여 펄스 에너지 및 타이밍 매개 변수에 대한 레이저 유도 내역 분광학 결과의 의존

The  dependence of some LIBS detection capabilities on lower pulse energies (&lt;100  mJ) and timing parameters were examined using synthetic silicate ...

연구

화학

An Inverse Analysis Approach to the Characterization of Chemical Transport in Paints

The ability to directly characterize chemical transport and interactions that occur within a material (i.e., subsurface dynamics) is a vital component in understanding contaminant mass transport and the ability to decontaminate materials. If a material is contaminated, over time, the transport of highly toxic chemicals (such as chemical warfare agent species) out of the material can result in vapor exposure or transfer to the skin, which can result in percutaneous exposure to personnel who interact with the material. Due to the high toxicity of chemical warfare agents, the release of trace chemical quantities is of significant concern. Mapping subsurface concentration distribution and transport characteristics of absorbed agents enables exposure hazards to be assessed in untested conditions. Furthermore, these tools can be used to characterize subsurface reaction dynamics to ultimately design improved decontaminants or decontamination procedures. To achieve this goal, an inverse analysis mass transport modeling approach was developed that utilizes time-resolved mass spectroscopy measurements of vapor emission from contaminated paint coatings as the input parameter for calculation of subsurface concentration profiles. Details are provided on sample preparation, including contaminant and material handling, the application of mass spectrometry for the measurement of emitted contaminant vapor, and the implementation of inverse analysis using a physics-based diffusion model to determine transport properties of live chemical warfare agents including distilled mustard (HD) and the nerve agent VX.

In this paper, a procedure for quantifying the mass transport parameters of chemicals in various materials is presented. This process involves employing an inverse-analysis based diffusion model to vapor emission profiles recorded by real-time, mass spectrometry in high vacuum.

페인트의 화학 물질 운송의 특성을 역 분석 접근

The ability to directly characterize chemical transport and interactions that occur within a material (i.e., subsurface dynamics) is a vital component in ...

Tuning a Parallel Segmented Flow Column and Enabling Multiplexed Detection

Active flow technology (AFT) is new form of column technology that was designed to overcome flow heterogeneity to increase separation performance in terms of efficiency and sensitivity and to enable multiplexed detection. This form of AFT uses a parallel segmented flow (PSF) column. A PSF column outlet end-fitting consists of 2 or 4 ports, which can be multiplexed to connect up to 4 detectors. The PSF column not only allows a platform for multiplexed detection but also the combination of both destructive and non-destructive detectors, without additional dead volume tubing, simultaneously. The amount of flow through each port can also be adjusted through pressure management to suit the requirements of a specific detector(s). To achieve multiplexed detection using a PSF column there are a number of parameters which can be controlled to ensure optimal separation performance and quality of results; that is tube dimensions for each port, choice of port for each type of detector and flow adjustment. This protocol is intended to show how to use and tune a PSF column functioning in a multiplexed mode of detection.

Here, we present a protocol for the operation and tuning of parallel segmented flow chromatography columns to enable multiplexed detection.

병렬 세그먼트 흐름 열 조정과 멀티 플렉스 감지 활성화

Active flow technology (AFT) is new form of column technology that was designed to overcome flow heterogeneity to increase separation performance in terms ...

Curtain Flow Column: Optimization of Efficiency and Sensitivity

Active Flow Technology (AFT) is a form of column technology that increases the separation performance of a HPLC column through the use of a specially purpose built multiport end-fitting(s). Curtain Flow (CF) columns belong to the AFT suite of columns, specifically the CF column is designed so that the sample is injected into the radial central region of the bed and a curtain flow of mobile phase surrounding the injection of solute prevents the radial dispersion of the sample to the wall. The column functions as an 'infinite diameter' column. The purpose of the design is to overcome the radial heterogeneity of the column bed, and at the same time maximize the sample load into the radial central region of the column bed, which serves to increase detection sensitivity. The protocol described herein outlines the system and CF column set up and the tuning process for an optimized infinite diameter 'virtual' column.

Here, we present a protocol for the operation and optimization of Active Flow Technology (AFT) column in Curtain flow (CF) mode for enhanced separation performance.

흐름 열 커튼 : 효율성과 감도의 최적화

Active Flow Technology (AFT) is a form of column technology that increases the separation performance of a HPLC column through the use of a specially ...

Facile Preparation of Internally Self-assembled Lipid Particles Stabilized by Carbon Nanotubes

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled (functionalized) CNTs are used as stabilizers to produce Pickering type oil-in-water (O/W) emulsions. Lipids namely, Dimodan U and Phytantriol are used as emulsifiers, which in excess water self-assemble into the bicontinuous cubic Pn3m phase. This highly viscous phase is fragmented into smaller particles using a probe ultrasonicator in presence of conventional surfactant stabilizers or CNTs as done here. Initially, the CNTs (powder form) are dispersed in water followed by further ultrasonication with the molten lipid to form the final emulsion. During this process the CNTs get coated with lipid molecules, which in turn are presumed to surround the lipid droplets to form a particulate emulsion that is stable for months. The average size of CNT-stabilized nanostructured lipid particles is in the submicron range, which compares well with the particles stabilized using conventional surfactants. Small angle X-ray scattering data confirms the retention of the original Pn3m cubic phase in the CNT-stabilized lipid dispersions as compared to the pure lipid phase (bulk state). Blue shift and lowering of the intensities in characteristic G and G&#39; bands of CNTs observed in Raman spectroscopy characterize the interaction between CNT surface and lipid molecules. These results suggest that the interactions between the CNTs and lipids are responsible for their mutual stabilization in aqueous solutions. As the concentrations of CNTs employed for stabilization are very low and lipid molecules are able to functionalize the CNTs, the toxicity of CNTs is expected to be insignificant while their biocompatibility is greatly enhanced. Hence the present approach finds a great potential in various biomedical applications, for instance, for developing hybrid nanocarrier systems for the delivery of multiple functional molecules as in combination therapy or polytherapy.

We report on a smart application of carbon nanotubes for kinetic stabilization of lipid particles that contain self-assembled nanostructures in their cores. The preparation of lipid particles requires rather low concentrations of carbon nanotubes permitting their use in biomedical applications such as drug delivery.

탄소 나노 튜브에 의해 안정화 내부 자기 조립 된 지질 입자의 용이 한 제조

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled ...

Preparation of Carbon Nanosheets at Room Temperature

Amphiphilic molecules equipped with a reactive, carbon-rich "oligoyne" segment consisting of conjugated carbon-carbon triple bonds self-assemble into defined aggregates in aqueous media and at the air-water interface. In the aggregated state, the oligoynes can then be carbonized under mild conditions while preserving the morphology and the embedded chemical functionalization. This novel approach provides direct access to functionalized carbon nanomaterials. In this article, we present a synthetic approach that allows us to prepare hexayne carboxylate amphiphiles as carbon-rich siblings of typical fatty acid esters through a series of repeated bromination and Negishi-type cross-coupling reactions. The obtained compounds are designed to self-assemble into monolayers at the air-water interface, and we show how this can be achieved in a Langmuir trough. Thus, compression of the molecules at the air-water interface triggers the film formation and leads to a densely packed layer of the molecules. The complete carbonization of the films at the air-water interface is then accomplished by cross-linking of the hexayne layer at room temperature, using UV irradiation as a mild external stimulus. The changes in the layer during this process can be monitored with the help of infrared reflection-absorption spectroscopy and Brewster angle microscopy. Moreover, a transfer of the carbonized films onto solid substrates by the Langmuir-Blodgett technique has enabled us to prove that they were carbon nanosheets with lateral dimensions on the order of centimeters.

We present the synthesis of an amphiphilic hexayne and its use in the preparation of carbon nanosheets at the air-water interface from a self-assembled monolayer of these reactive, carbon-rich molecular precursors.

실내 온도에서 탄소 나노 시트의 제조

Amphiphilic molecules equipped with a reactive, carbon-rich "oligoyne" segment consisting of conjugated carbon-carbon triple bonds self-assemble into ...

Functionalization of Single-walled Carbon Nanotubes with Thermo-reversible Block Copolymers and Characterization by Small-angle Neutron Scattering

We demonstrate a protocol for single-walled carbon nanotube functionalization using thermo-sensitive PEO-PPO-PEO triblock copolymers in an aqueous solution. In a carbon nanotube/PEO105-PPO70-PEO105 (poloxamer 407) aqueous solution, the amphiphilic poloxamer 407 adsorbs onto the carbon nanotube surfaces and self-assembles into continuous layers, driven by intermolecular interactions between constituent molecules. The addition of 5-methylsalicylic acid changes the self-assembled structure from spherical-micellar to a cylindrical morphology. The fabricated poloxamer 407/carbon nanotube hybrid particles exhibit thermo-responsive structural features so that the density and thickness of poloxamer 407 layers are also reversibly controllable by varying temperature. The detailed structural properties of the poloxamer 407/carbon nanotube particles in suspension can be characterized by small-angle neutron scattering experiments and model fit analyses. The distinct curve shapes of the scattering intensities depending on temperature control or addition of aromatic additives are well described by a modified core-shell cylinder model consisting of a carbon nanotube core cylinder, a hydrophobic shell, and a hydrated polymer layer. This method can provide a simple but efficient way for the fabrication and in-situ characterization of carbon nanotube-based nano particles with a structure-tunable encapsulation.

A method for the functionalization of carbon nanotubes with structure-tunable polymeric encapsulation layers and structural characterization using small-angle neutron scattering is presented.

작은 각도 중성자 산란에 의한 열 가역적 블록 공중 합체 및 특성 단일 벽 탄소 나노 튜브의 기능화

We demonstrate a protocol for single-walled carbon nanotube functionalization using thermo-sensitive PEO-PPO-PEO triblock copolymers in an aqueous ...

Characterizing Electron Transport through Living Biofilms

Here we demonstrate the method of electrochemical gating used to characterize electrical conductivity of electrode-grown microbial biofilms under physiologically relevant conditions.1 These measurements are performed on living biofilms in aqueous medium using source and drain electrodes patterned on a glass surface in a specialized configuration referred to as an interdigitated electrode (IDA) array. A biofilm is grown that extends across the gap connecting the source and drain. Potentials are applied to the electrodes (ES and ED) generating a source-drain current (ISD) through the biofilm between the electrodes. The dependency of electrical conductivity on gate potential (the average of the source and drain potentials, EG = [ED + ES]/2) is determined by systematically changing the gate potential and measuring the resulting source-drain current. The dependency of conductivity on gate potential provides mechanistic information about the extracellular electron transport process underlying the electrical conductivity of the specific biofilm under investigation. The electrochemical gating measurement method described here is based directly on that used by M. S. Wrighton2,3 and colleagues and R. W. Murray4,5,6 and colleagues in the 1980&#39;s to investigate thin film conductive polymers.

A protocol for measuring electrical conductivity of living microbial biofilms under physiologically relevant conditions is presented.

특성화 생활 Biofilms 통해 전자 전송

Here we demonstrate the method of electrochemical gating used to characterize electrical conductivity of electrode-grown microbial biofilms under ...

Grafting Multiwalled Carbon Nanotubes with Polystyrene to Enable Self-Assembly and Anisotropic Patchiness

We demonstrate a straightforward protocol to graft pristine multiwalled carbon nanotubes (MWCNTs) with polystyrene (PS) chains at the sidewalls through a free-radical polymerization strategy to enable the modulation of the nanotube surface properties and produce supramolecular self-assembly of the nanostructures. First, a selective hydroxylation of the pristine nanotubes through a biphasic catalytically mediated oxidation reaction creates superficially distributed reactive sites at the sidewalls. The latter reactive sites are subsequently modified with methacrylic moieties using a silylated methacrylic precursor to create polymerizable sites. Those polymerizable groups can address further polymerization of styrene to produce a hybrid nanomaterial containing PS chains grafted to the nanotube sidewalls. The polymer-graft content, amount of silylated methacrylic moieties introduced and hydroxylation modification of the nanotubes are identified and quantified by Thermogravimetric Analysis (TGA). The presence of reactive functional groups hydroxyl and silylated methacrylate are confirmed by Fourier Transform Infrared Spectroscopy (FT-IR). Polystyrene-grafted carbon nanotube solutions in tetrahydrofuran (THF) provide wall-to-wall collinearly self-assembled nanotubes when cast samples are analyzed by transmission electron microscopy (TEM). Those self-assemblies are not obtained when suitable blanks are similarly cast from analogous solutions containing non-grafted counterparts. Therefore, this method enables the modification of the nanotube anisotropic patchiness at the sidewalls which results into spontaneous auto-organization at the nanoscale.

A procedure for the synthesis of polystyrene-grafted multiwalled carbon nanotubes using successive chemical modification steps to selectively introduce the polymer chains to the sidewalls and their self-assembly via anisotropic patchiness is presented.

자기 집합에 있도록 폴리스 티 렌과 이방성 Patchiness Multiwalled 탄소 나노튜브를 접목

We demonstrate a straightforward protocol to graft pristine multiwalled carbon nanotubes (MWCNTs) with polystyrene (PS) chains at the sidewalls through a ...

Electrochemical Impedance Spectroscopy as a Tool for Electrochemical Rate Constant Estimation

Electrochemical impedance spectroscopy (EIS) was used for advanced characterization of organic electroactive compounds along with cyclic voltammetry (CV). In the case of fast reversible electrochemical processes, current is predominantly affected by the rate of diffusion, which is the slowest and limiting stage. EIS is a powerful technique that allows separate analysis of stages of charge transfer that have different AC frequency response. The capability of the method was used to extract the value of charge transfer resistance, which characterizes the rate of charge exchange on the electrode-solution interface. The application of this technique is broad, from biochemistry up to organic electronics. In this work, we are presenting the method of analysis of organic compounds for optoelectronic applications.

Electrochemical impedance spectroscopy (EIS) of species that undergo reversible oxidation or reduction in solution was used for determination of rate constants of oxidation or reduction.

전기 화학 임피던스 분 광 전기 화학 속도 상수 추정을 위한 도구로

Electrochemical impedance spectroscopy (EIS) was used for advanced characterization of organic electroactive compounds along with cyclic voltammetry (CV). ...