Surface chemicals concepts of flotation de-inking

Theander, Katarina; Pugh, R.J.

doi:10.1016/j.colsurfa.2003.12.014

Cited by 38 publications

(18 citation statements)

References 21 publications

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“…The asymmetry can be made so great that the air appears to tear. This symmetry breaking may be important in numerous applications [15,16,17], and for understanding other physical processes which are modeled as the formation of a singularity, such as star or black hole formation [18] and supernova explosions [19]. Thus our experimental observation of the breakdown of cylindrical symmetry in the air bubble demonstrates a new view of dynamical singularities that may be relevant even on a celestial scale.…”

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confidence: 84%

Breakup of Air Bubbles in Water: Memory and Breakdown of Cylindrical Symmetry

et al. 2006

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Using high-speed video, we have studied air bubbles detaching from an underwater nozzle. As a bubble distorts, it forms a thin neck which develops a singular shape as it pinches off. As in other singularities, the minimum neck radius scales with the time until breakup. However, because the air-water interfacial tension does not drive breakup, even small initial cylindrical asymmetries are preserved throughout the collapse. This novel, non-universal singularity retains a memory of the nozzle shape, size and tilt angle. In the last stages, the air appears to tear instead of pinch.PACS numbers: 47.55.db, 47.55.df, 02.40.Xx The delightful tingling felt when drinking carbonated beverages, the glee of children blowing bubbles in a bathtub, and the importance of deep underwater fissures venting gasses into the oceans hint at the richness and significance of bubble formation in determining the texture and composition of our world. However, the process by which a bubble is formed is still full of surprises. A drop or bubble breaks up by forming a neck that thins to atomic dimensions, a process described as an approach towards a singularity where physical quantities such as stress or pressure grow infinitely large. Singularities often organize the overall dynamical evolution of nonlinear systems. Each symmetry in nature implies an underlying conservation law, so that the symmetries of the singularity associated with pinch-off naturally have important consequences for its dynamics. It was previously believed [1,2,3,4,5,6,7,8,9,10,11,12] that the pinching neck of any drop or bubble would become cylindrically (i.e. azimuthally) symmetric in the course of pinch-off. Recently, pinching necks of air in water were observed to lose cylindrical symmetry in the course of detachment [13,14].Here we show that this loss of symmetry is caused by a new form of memory in singular dynamics: even a small asymmetry in the initial conditions is preserved throughout bubble detachment. This novel singularity retains a memory of the nozzle shape, size and tilt angle. The asymmetry can be made so great that the air appears to tear. This symmetry breaking may be important in numerous applications [15,16,17], and for understanding other physical processes which are modeled as the formation of a singularity, such as star or black hole formation [18] and supernova explosions [19]. Thus our experimental observation of the breakdown of cylindrical symmetry in the air bubble demonstrates a new view of dynamical singularities that may be relevant even on a celestial scale.Singularities govern the dynamics in many familiar break-up events, such as the dispersal of oil drops into * Electronic address: nkeim@uchicago.edu vinegar during the making of a salad dressing, or the dripping of water from a leaky faucet. For many fluid pairs -for example, one viscous fluid breaking in a surrounding fluid of high viscosity [7,8,12] -the shape and dynamics of the pinching neck depend solely on the fluid parameters, as the breakup forgets its initial conditions on ...

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confidence: 84%

Breakup of Air Bubbles in Water: Memory and Breakdown of Cylindrical Symmetry

et al. 2006

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“…The sealed samples of the nonionic surfactants were stored in a refrigerator. The nonionic surfactant has a similar structure to surfactants used in flotation de-inking plants as dispersing and ink detachment agents [12]. The surfactant was dissolved in Millipore water set to pH 10 with concentrated sodium hydroxide and the ionic strength was set to 1 mM with NaCl previously roasted at 500 • C for 24 h.…”

Section: Methodsmentioning

confidence: 99%

Friction force measurements relevant to de-inking by means of atomic force microscope

Theander

Pugh²,

Rutland

2005

Journal of Colloid and Interface Science

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“…It seems that effective ink removal is obtained under the condition that the surface tension is not very low and the (negative) charge is not too high, because higher charge leads to stabilization of fine particles which cannot be removed by flotation or adsorption deinking. The influence of surface tension was described by different authors [3,4,9]. The flotation efficiency depends on the concentration of surfactant.…”

Section: Discussionmentioning

confidence: 99%