• 제목/요약/키워드: polyelectrolytes

검색결과 95건 처리시간 0.028초

Flocculation properties of a natural polyampholyte: The optimum condition toward clay suspensions

  • Nazarzadeh, Mohammad;Nikfarjam, Nasser;Qazvini, Nader Taheri
    • Environmental Engineering Research
    • /
    • 제22권3호
    • /
    • pp.255-265
    • /
    • 2017
  • Polyelectrolytes are commonly used as flocculants in drinking water treatment. However the growing concerns about their toxicity have motivated the search for biocompatible flocculants. Here, we show that gelatin, a natural amphoteric polyelectrolyte, can be effectively adsorbed on clay surfaces and can potentially be a suitable substitute for existing flocculants. The adsorption of gelatin from its aqueous solution onto the mineral clay surfaces at different conditions was systematically investigated using the design of experiments methodology. The gelatin adsorption was found to vary considerately with pH variation showed a maximum adsorption at its isoelectric point. The amount of adsorbed gelation increased with increasing pH from 3 to 5, attained a maximum at pH 5 and then decreased with increasing pH from 5 to 11. Similarly, the amount of adsorbed gelatin showed decreasing trends around salt concentration of 0.05 M and temperature $35^{\circ}C$. On the other hand, the adsorption was continuously increased with time and polymer concentration in the range of 0.1-0.9 mg/dL. Finally, the jar tests confirmed the ability of gelatin for using a natural flocculant for water treatment.

고분자전해질 LbL multilayering 처리된 섬유와 형광증백제와의 반응성 (Interaction between Polyelectrolytes Layer-by-Layer Assembled Fibers and Fluorescent Whitening Agent)

  • 심규정;이성린;진성민;류재호;윤혜정
    • 펄프종이기술
    • /
    • 제42권4호
    • /
    • pp.71-77
    • /
    • 2010
  • To utilize modified pulp fibers in papermaking system, it is necessary to evaluate the interaction between modified fibers and papermaking additives. Fluorescent whitening agent (FWA) is an important additive which has been widely used for production of writing and printing paper. We modified pulp fiber surface by Layer-by-Layer multilayering of polyelectrolytes, and investigated the interaction between these fibers and FWA used in internal addition or surface treatment. Pulp fiber with cationic surface charge showed a good affinity to internal FWA. For FWA in surface sizing agent, whiteness and brightness of paper was dependent on pickup weight and polyelectrolyte type. Pulp fibers with C-starch/PSS multilayer showed better optical properties than poly-DADMAC/PSS treatment. It indicated that polyelectrolyte type in Layer-by-Layer multilayering as well as a good affinity to FWA is important to get better whiteness and brightness.

셀룰로오스 나노피브릴 현탁액의 탈수성 평가 및 양이온성 고분자전해질 투입의 영향 (Evaluation of Dewatering of Cellulose Nanofibrils Suspension and Effect of Cationic Polyelectrolyte Addition on Dewatering)

  • 류재호;심규정;윤혜정
    • 펄프종이기술
    • /
    • 제46권6호
    • /
    • pp.78-86
    • /
    • 2014
  • Since cellulose nanofibrils (CNF) has large specific surface area and high water holding capacity, it is very difficult task to remove water from the CNF suspension. However, dewatering of CNF suspension is a prerequisite of following processes such as mat forming and drying for the application of CNF. In this study, we evaluated the drainage of cellulose fibers suspension under vacuum and pressure conditions depending on the number of grinding passes. Also, the effect of the addition of cationic polyelectrolyte on dewatering ability of CNF suspension was investigated. Regardless of dewatering condition, the total drained water amount as well as the drainage rate were decreased with an increase in the number of grinding passes. Pressure dewatering equipment enables us to prepare wet CNF mat with relatively higher grammage. The cationic polyelectrolytes improved the dewatering ability of CNF suspension by controlling the zeta potential of CNF. The fast drainage was obtained when CNF suspension had around neutral zeta potential.

Flocculation Characteristics of Kaoline Suspensions in Water by Cationic Polyelectrolytes

  • Kam, Sang-Kyu;Kim, Dae-kyoung;Ko, Byung-Churl;Moon, Chang-Seong;Lee, Min-Gyu
    • 한국환경과학회지
    • /
    • 제11권2호
    • /
    • pp.93-102
    • /
    • 2002
  • Using a simple continuous optical technique, coupled with measurements of zeta potential, the flocculation characteristics of kaoline suspensions of different content(15, 35 and 55 NTU) by several cationic polyelectrolytes, has been examined. The optimum mixing is obtained under a constant stirring of 200 rpm, differently from a general flocculation test. The charge density of a polyelectrolyte is important in determining the optimum dosage and in the removal of kaoline particles. The optimum dosage is less for the polyelectrolyte of higher charge density and is the same regardless of kaoline content. At the dosage, the removal of kaoline particles is higher for the polyelectrolyte of higher charge density and zeta potential of kaoline particles reaches to near zero. The rate of adsorption and flocculation rate have been found to be affected by charge density and molecular weight of a polyelelctrolyte and the content of kaoline particles.

간헐포기 소화 슬러지의 고분자 응집제에 의한 개량과 입도 분포 변화에 관한 연구 (A Study on the Conditioning with Polymer and the Particle Size Distribution of Intermittent Aerobic Digestion Sludge)

  • 김희준;김성홍;최재성
    • 한국환경보건학회지
    • /
    • 제30권3호
    • /
    • pp.253-258
    • /
    • 2004
  • Synthetic organic polyelectrolytes can be used to condition sludges to enhance their dewaterability. Intermittent aerobic digestion is an useful digestion technology and has many advantages like neutral pH, low installation cost and easiness to operation. The objectives of this study were to investigate the dewaterability of intemittent aerobic digestion sludge and to find the relationship between dewaterability and particle size distribution change under the conditioning of intermittent aerobic digestion sludge by cationic polyelectrolyte. Digested sludge from intermittent aerobic digestion was used and cationic polyacrylamide polymer was added as a conditioner. CST(capillary suction time), TTF(time-to-filtration) were tested as a dewaterability index and the number of particle distribution was analyzed using particle size analyzer. The results indicate that cationic polyelectrolytes is useful to enhance dewaterability of intermittent aerobic digestion sludge. Mean particle diameter was increased as polymer dosage increased and its value was reached up to 100 mm on the condition of optimal cationic polymer dosage. CST and TTF are well correlated with mean particle diameter when the weighting order is 1.7. By the optimal conditioning with cationic polymer, particles in the filtrate are also reduced significantly and this means that conditioning is helpful to main stream by reducing SS loading from return flow.

양친매성 고분자전해질 도입을 통한 리포좀의 안정도 증진에 관한 연구 (Improved Stability of Liposome by Association of Amphiphilic Polyelectrolytes)

  • 조은철;임형준;김준오;장이섭
    • 대한화장품학회지
    • /
    • 제33권1호
    • /
    • pp.1-6
    • /
    • 2007
  • 일반적으로 cyclodextrin (CD)은 liposome의 구조를 불안정하게 만드는 것으로 알려져 있다. 본 연구에서는 양친매성 고분자전해질을 리포좀에 도입하여 CD에 대한 리포좀의 안정도를 증진시키는 연구를 수행하였다. Transmission electron microscopy와 photocorrelation spectroscopy 결과들로부터 ${\beta}-CD$ (${\beta}CD$)와 hydroxypropyl-${\beta}CD$ ($HP{\beta}CD$)를 함유하는 리포좀에 고분자가 도입되었을 때 CD를 함유하는 phosphatidylcholine (PC)-cholesterol (Chol) 리포좀보다 우수한 구조적 안정성을 나타내었다. 또한, rhaponticin (Rh)을 $HP{\beta}CD$에 포접시키고 이를 함유하는 PC-Chol 리포좀과 고분자가 도입된 리포좀의 안정도를 비교해 보았을 경우도 마찬가지로 고분자가 도입된 리포좀이 월등히 향상된 구조적인 안정성을 나타내는 것을 확인하였다. 이와 더불어 guinea pig의 피부조직을 사용하고 franz-cell을 통한 in vitro 피부흡수실험을 수행한 결과, $HP{\beta}CD$에 의해 가용화된 Rh의 피부흡수가 고분자가 도입된 리포좀에 의해 증진됨을 확인할 수 있었다. 상기 결과들은 양친매성 고분자 전해질의 도입에 따라 CD에 의해 가용화된 특정한 활성성분을 함유하는 리포좀의 구조적인 안정성을 효과적으로 증진시킬 수 있음을 확인시켜 주었으며, 이렇게 향상된 리포좀의 구조적인 안정성을 통해 약물전달시스템 측면에서 많은 응용이 가능할 것으로 생각된다.