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Pugh, Robert
Alternative names
Publications (10 of 18) Show all publications
Alexandrova, L., Kota, H. R., Forssberg, E., Grigorov, L. & Pugh, R. (2011). The influence of mixed cationic-anionic surfactants on the three-phase contact parameters in silica-solution systems (ed.). Paper presented at . Colloids and Surfaces A: Physicochemical and Engineering Aspects, 373(1-3), 145-151
Open this publication in new window or tab >>The influence of mixed cationic-anionic surfactants on the three-phase contact parameters in silica-solution systems
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2011 (English)In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 373, no 1-3, p. 145-151Article in journal (Refereed) Published
Abstract [en]

The formation of thin wetting films on silica surface from aqueous solution of a) tetradecyltrimetilammonium bromide (C14TAB) and (b) surfactant mixture of the cationic C14TAB with the anionic sodium alkyl- (straight chain C12-, C14- and C16-) sulfonates, was studied using the microscopic thin wetting film method developed by Platikanov. Film lifetimes, three-phase contact (TPC) expansion rates, receding contact angles and surface tension were measured. It was found that the mixed surfactants caused lower contact angles, lower rates of the thin aqueous film rupture and longer film lifetimes, as compared to the pure C14TAB. This behavior was explained by the strong initial adsorption of interfacial complexes from the mixed surfactant system at the air/solution interface, followed by adsorption at the silica interface. The formation of the interfacial complexes at the air/solution interface was proved by means of the surface tension data. It was also shown, that the chain length compatibility between the anionic and cationic surfactants controls the strength of the interfacial complex and causes synergistic lowering in the surface tension. The film rupture mechanism was explained by the heterocoagulation mechanism between the positively charged air/solution interface and the solution/silica interface, which remained negatively charged.

National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-3685 (URN)10.1016/j.colsurfa.2010.10.040 (DOI)000286862300021 ()2-s2.0-78649951363 (Scopus ID)182bc110-edad-11df-8b36-000ea68e967b (Local ID)182bc110-edad-11df-8b36-000ea68e967b (Archive number)182bc110-edad-11df-8b36-000ea68e967b (OAI)
Note
Validerad; 2011; 20101111 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Alexandrova, L., Rao, K. H., Forssberg, E., Grigorov, L. & Pugh, R. (2009). Three-phase-contact parameters measurements for silica-mixed cationic-anionic surfactant systems (ed.). Paper presented at . Colloids and Surfaces A: Physicochemical and Engineering Aspects, 348(1-3), 228-233
Open this publication in new window or tab >>Three-phase-contact parameters measurements for silica-mixed cationic-anionic surfactant systems
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2009 (English)In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 348, no 1-3, p. 228-233Article in journal (Refereed) Published
Abstract [en]

The stability and interactions in thin wetting films between the silica surface and air bubble containing (a) straight chain C10 amine and (b) cationic/anionic surfactant mixture of a straight chain C10 amine with sodium C8, C10 and (straight chain) C12 sulfonates, were studied using the microscopic thin wetting film method developed by Platikanov [Platikanov D., J. Phys. Chem., 68 (1964) 3619]. Film lifetimes, three-phase contact (TPC) expansion rate, receding contact angles and surface tension were measured. The presence of the mixed cationic/anionic surfactants was found to lessen contact angles and suppresses the thin aqueous film rupture, thus inducing longer film lifetime, as compared to the pure amine system. In the case of mixed surfactants hetero-coagulation could arise through the formation of positively charged interfacial complexes. Mixed solution of cationic and anionic surfactants shows synergistic lowering in surface tension. The formation of the interfacial complex at the air/solution interface was confirmed by surface tension data. It was also shown, that the chain length compatibility between the anionic and cationic surfactants system controls the strength of the interfacial complex. The observed phenomena were discussed in terms of the electrostatic heterocoagulation theory, where the interactions can be attractive or repulsive depending on the different surface activity and charge of the respective surfactants at the two interfaces.

National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-6005 (URN)10.1016/j.colsurfa.2009.07.028 (DOI)000270623900036 ()2-s2.0-69249218948 (Scopus ID)4330e6b0-7d1f-11de-8da0-000ea68e967b (Local ID)4330e6b0-7d1f-11de-8da0-000ea68e967b (Archive number)4330e6b0-7d1f-11de-8da0-000ea68e967b (OAI)
Note
Validerad; 2009; 20090730 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Pugh, R. (2005). Experimental techniques for studying the structure of foams and froths (ed.). Paper presented at . Advances in Colloid and Interface Science, 114-115, 239-251
Open this publication in new window or tab >>Experimental techniques for studying the structure of foams and froths
2005 (English)In: Advances in Colloid and Interface Science, ISSN 0001-8686, E-ISSN 1873-3727, Vol. 114-115, p. 239-251Article in journal (Refereed) Published
Abstract [en]

Several techniques are described in this review to study the structure and the stability of froths and foams. Image analysis proved useful for detecting structure changes in 2-D foams and has enabled the drainage process and the gradients in bubble size distribution to be determined. However, studies on 3-D foams require more complex techniques such as Mutiple-Light Scattering Methods, Microphones and Optical Tomography. Under dynamic foaming conditions, the Foam Scan Column enables the water content of foams to be determined by conductivity analysis. It is clear that the same factors, which play a role in foam stability (film thickness, elasticity, etc.) also have a decisive influence on the stability of isolated froth or foam films. Therefore, the experimental thin film balance (developed by the Bulgarian Researchers) to study thinning of microfilms formed by a concave liquid drop suspended in a short vertical capillary tube has proved useful. Direct measurement of the thickness of the aqueous microfilm is determined by a micro-reflectance method and can give fundamental information on drainage and thin film stability. It is also important to consider the influence of the mineral particles on the stability of the froth and it have been shown that particles of well defined size and hydrophobicity can be introduced into the thin film enabling stabilization/destabilization mechanisms to be proposed. It has also been shown that the dynamic and static stability can be increased by a reduction in particle size and an increase in particle concentration

National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-13812 (URN)10.1016/j.cis.2004.08.005 (DOI)000230186700019 ()2-s2.0-19744363829 (Scopus ID)d19cf2f0-43c0-11df-a0f4-000ea68e967b (Local ID)d19cf2f0-43c0-11df-a0f4-000ea68e967b (Archive number)d19cf2f0-43c0-11df-a0f4-000ea68e967b (OAI)
Note
Validerad; 2005; 20100409 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Tan, S. N., Pugh, R., Fornasiero, D., Sedev, R. & Ralston, J. (2005). Foaming of polypropylene glycols and glycol/MIBC mixture (ed.). Paper presented at . Minerals Engineering, 18(2), 179-188
Open this publication in new window or tab >>Foaming of polypropylene glycols and glycol/MIBC mixture
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2005 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 18, no 2, p. 179-188Article in journal (Refereed) Published
Abstract [en]

The surface tension and foamability of a series of polypropylene glycols (PPG) with average molecular weights (MW) ranging from 200 to 2000 g mol-1 and hydrophilic-lipophilic balance (HLB) values ranging from 10.4 to 5.8 were compared to methyl isobutyl carbinol (MIBC), 4-methyl-2-pentanol (MW102 g mol-1 and HLB 6.1). Experiments were carried out using a modified Bikermann column in which the foam heights were determined at a range of gas flow rates and retention times were calculated at different foamer concentrations. These studies show the six-carbon polypropylene glycol (PPG400) with HLB value of 9.7 is an unusually strong frother. Since many industrial foamers/frothers commonly contain a mixture of chemical types, we have also studied the foaming behaviour of mixed systems of PPGs and MIBC at a range of concentrations. The foaming data indicated that a synergistic effect occurred for several of the mixed systems with differences in HLB values, which resulted in an increase in foam height compared to the performance of the individual systems. Dynamic surface tension measurements, determined in the short time span range of 0.1-10 s, correlated with the synergistic effect and it was found that the blended systems gave a higher dynamic surface tension gradient compared to the individual PPGs. It could be suggested that the mixed foamer (containing high HLB and low HLB value components) produce closed packed, molecular cohesive films at the air/solution interface giving greater surface elasticity, which appeared to increase foamability

National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-6858 (URN)10.1016/j.mineng.2004.08.017 (DOI)000227139900006 ()52cd5ad0-4a16-11df-a0f4-000ea68e967b (Local ID)52cd5ad0-4a16-11df-a0f4-000ea68e967b (Archive number)52cd5ad0-4a16-11df-a0f4-000ea68e967b (OAI)
Note
Validerad; 2005; 20100417 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Lu, S., Pugh, R. & Forssberg, E. (2005). Interfacial separation of particles (ed.). Paper presented at . Amsterdam: Elsevier
Open this publication in new window or tab >>Interfacial separation of particles
2005 (English)Book (Other academic)
Abstract [en]

Interfacial Separation of Particles is concerned with the processing and separation of fine solid particles in liquid solutions using interfacial technology. Interfacial separation has been finding wide application in many industrial fields, such as pigment and filler production, mineral processing, environmental protection, hydrometallurgy, bioengineering, food and beverage industry and chemical industry. This book describes all interfacial separation techniques and discusses the general and specific fundamentals of the techniques. The book intends to promote theoretical understanding and the more promising developments of interfacial separation technology whilst broadening the reader's background knowledge of industrial suspensions

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2005. p. 321
Series
Studies in interface science, ISSN 1383-7303 ; 20
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-16715 (URN)d3a65920-690c-11db-8cbe-000ea68e967b (Local ID)0-444-51606-9 (ISBN)d3a65920-690c-11db-8cbe-000ea68e967b (Archive number)d3a65920-690c-11db-8cbe-000ea68e967b (OAI)
Note
Godkänd; 2005; 20061031 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Alexandrova, L., Rao, K. H., Forssberg, E., Pugh, R. & Grigorov, L. (2003). Thin film studies in mixed cationic-anionic surfactant system (ed.). In: (Ed.), Leon Lorenzen (Ed.), Proceedings of the XXII International Mineral Processing Congress: . Paper presented at International Mineral Processing Congress : 29/09/2003 - 03/10/2003 (pp. 838-846). Marshalltown, South Africa: South African Institute of Mining and Metallurgy
Open this publication in new window or tab >>Thin film studies in mixed cationic-anionic surfactant system
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2003 (English)In: Proceedings of the XXII International Mineral Processing Congress / [ed] Leon Lorenzen, Marshalltown, South Africa: South African Institute of Mining and Metallurgy, 2003, p. 838-846Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Marshalltown, South Africa: South African Institute of Mining and Metallurgy, 2003
National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-34545 (URN)8c41cda0-b1a0-11de-8293-000ea68e967b (Local ID)0958460922 (ISBN)8c41cda0-b1a0-11de-8293-000ea68e967b (Archive number)8c41cda0-b1a0-11de-8293-000ea68e967b (OAI)
Conference
International Mineral Processing Congress : 29/09/2003 - 03/10/2003
Note
Godkänd; 2003; Bibliografisk uppgift: CD-ROM; 20091005 (hrao)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Shen, H., Pugh, R. & Forssberg, E. (2002). Floatability, selectivity and flotation separation of plastics by using a surfactant (ed.). Paper presented at . Colloids and Surfaces A: Physicochemical and Engineering Aspects, 196(1), 63-70
Open this publication in new window or tab >>Floatability, selectivity and flotation separation of plastics by using a surfactant
2002 (English)In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 196, no 1, p. 63-70Article in journal (Other academic) Published
Abstract [en]

In this paper, the floatability of seven plastics (POM. PVC, PET. PMMA, PC., PS and ABS) in the presence of alkyl ethoxylated nonionic surfactant (15-S-7) was investigated. It was found that the floatability of all the plastics decreases with the addition of the surfactant; but they are different in floatability and follow the order POM < PVC < PMMA < PET < PC < ABS < PS. From the separation test results of several plastic mixtures, it was shown that Gamma flotation method not only can be used to separate plastics mixture with different density, such as separation of POM and PVC from PC, POM and PVC from PS and ABS, PET and PMMA from PS and ABS, but also can be used to separate plastics mixture with similar density, such as separation of PMMA from PC. Products with grade higher than 99%. and recovery higher than 97% can be obtained for the separation of some plastic mixtures. Finally, surface chemical factors, such as wettability of plastics and surface tension of flotation medium, and gravity factors, such as particle density and shape, were studied, It was found that the depressing effect of surfactant 15-S-7 on the plastics is mainly due to the reduced liquid surface tension, and flotation selectivity for the plastics with identical particle size is dominated by contact angle, particle density and shape. (C) 2002 Elsevier Science B.V. All rights reserved.

National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-7745 (URN)10.1016/S0927-7757(01)00706-3 (DOI)000173356300009 ()2-s2.0-0036138228 (Scopus ID)628b6850-a248-11db-8975-000ea68e967b (Local ID)628b6850-a248-11db-8975-000ea68e967b (Archive number)628b6850-a248-11db-8975-000ea68e967b (OAI)
Note
Godkänd; 2002; 20070112 (pafi)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Shen, H., Forssberg, E. & Pugh, R. (2002). Selective flotation separation of plastics by chemical conditioning with methyl cellulose (ed.). Paper presented at . Resources, Conservation and Recycling, 35(4), 229-241
Open this publication in new window or tab >>Selective flotation separation of plastics by chemical conditioning with methyl cellulose
2002 (English)In: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 35, no 4, p. 229-241Article in journal (Refereed) Published
Abstract [en]

The floatability of seven plastics (POM, PVC, PET, PMMA, PC, PS and ABS) in the presence of methyl cellulose (MC) and separation of plastics mixtures were investigated in this paper. It was found that the seven plastics can be separated into three groups by using the wetting agent MC. Group one includes POM and PVC. They are depressed at very low MC concentrations. Group two, including PET, PMMA and PC, has an intermediate floatability. Group three (ABS and PS) has a high floatability. They are almost not depressed within the given MC concentration range. In order to understand the mechanism of selective flotation of plastics and the chemical conditioning process, surface chemical factors, such as wettability of plastics and surface tension of flotation medium, and gravity factors, such as particle density and shape, were studied. It was found that the depressing effect of MC on plastics is ascribed mainly to its adsorption on the plastics surfaces. The MC molecules absorbed on plastics expose some of their polar groups oriented towards the aqueous phase, hence making the plastics surfaces hydrophilic. In addition, flotation selectivity for the plastics is dominated not only by wettability of plastics, but also by particle size, density and shape.

National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-2876 (URN)10.1016/S0921-3449(02)00003-4 (DOI)000176085800002 ()2-s2.0-0036235961 (Scopus ID)09934190-a23a-11db-8975-000ea68e967b (Local ID)09934190-a23a-11db-8975-000ea68e967b (Archive number)09934190-a23a-11db-8975-000ea68e967b (OAI)
Note
Validerad; 2002; 20070112 (pafi)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Shen, H., Forssberg, E. & Pugh, R. (2001). Selective flotation separation of plastics by particle control (ed.). Paper presented at . Resources, Conservation and Recycling, 33(1), 37-50
Open this publication in new window or tab >>Selective flotation separation of plastics by particle control
2001 (English)In: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 33, no 1, p. 37-50Article in journal (Refereed) Published
Abstract [en]

A study on the control of particle size distribution (PSD) of the ground carbonate product in stirred media mills (wet Drais stirred bead mill and dry Sala Agitated Mill) is presented in this paper. The results indicated that the slope of product size distribution can be controlled by altering some operating parameters, such as size of grinding media and tip or peripheral speed. The profile of product size distribution from the stirred media mills was found to follow most closely the Rosin-Rammler-Bennett (RRB) model.

National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-2504 (URN)10.1016/S0921-3449(01)00056-8 (DOI)000169774200003 ()2-s2.0-0034985333 (Scopus ID)01f4cb50-aa2a-11db-aeba-000ea68e967b (Local ID)01f4cb50-aa2a-11db-aeba-000ea68e967b (Archive number)01f4cb50-aa2a-11db-aeba-000ea68e967b (OAI)
Note
Validerad; 2001; 20070122 (pafi)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Forssberg, E., Pugh, R. & Shen, H. (1999). Review of plastics waste recycling and the flotation of plastics (ed.). Paper presented at . Resources, Conservation and Recycling, 25(2), 85-109
Open this publication in new window or tab >>Review of plastics waste recycling and the flotation of plastics
1999 (English)In: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 25, no 2, p. 85-109Article in journal (Refereed) Published
Abstract [en]

This paper summarizes the importance of plastic waste recycling and plastic waste separation. Based on an analysis of the physical and chemical characteristics of plastics and plastic waste, the potentials and limitations of several technological processes are discussed. In addition, a review of the surface chemical aspects of plastic flotation is presented. It can be concluded that the flotation of plastics is a fairly flexible technique and could prove to be a useful process for the separation of mixtures of several different types of plastics. However, more research and development effort is required before this technology can be introduced to industry.

National Category
Metallurgy and Metallic Materials
Research subject
Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-15823 (URN)10.1016/S0921-3449(98)00017-2 (DOI)2-s2.0-0033082140 (Scopus ID)f6195630-b1ee-11db-bf9d-000ea68e967b (Local ID)f6195630-b1ee-11db-bf9d-000ea68e967b (Archive number)f6195630-b1ee-11db-bf9d-000ea68e967b (OAI)
Note
Godkänd; 1999; 20070201 (pafi)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved

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