Application of Surfactant auxiliaries
Wirote Sarakarnkosol
Surfactant containing auxiliary
Wetting and Rewetting agent Scouring agent Emulsifying and Dispersing agent Levelling agent Defoaming agent
Wetting and Rewetting agent:
Wetting power of surfactant
Middle hydrophilic group surfactant gave higher wetting power than those of end.
Higher wetting power Lower wetting power
Wetting power of surfactant
Branch or aromatic hydrophobic chain is prefers.
Lower wetting power
Higher wetting power
or
Wetting power of surfactant
Optimum of EO in non-ionic surfactant unit gave maximum wetting power.
EO EO EOEOEO
EO EO EOEOEO EO EO EOEOEO
EO EO EO Low solubility : Lower wetting power
High water affinity :Lower wetting power
Optimum EO : Highest wetting power
pH of wetting agent application
pH Anionic wetting agent Nonionic wetting agent
Strongly alkaline
Easily soluble surfactants with relatively low MW are applicable. Those with ester linkage are hydrolyse
Not-applicable (insoluble)
Weakly alkaline Applicable Generally applicable
Nearly neutral Applicable Applicable
Weakly acidApplicable, Sulphate type surfactant are decomposed dependinf on conditions.
Applicable
Strongly acidGenerally not applicable. In some cases particular sulphonate type are applicable
Generally applicable
Mercerization, Causticization
General scouring, bleaching,dyeing (Vat, Sulphur)
Desizing, Dyeing (Direct, Reactive)
Strongly acid
Strongly alkaline
Weakly alkaline
Nearly neutral
Weakly acid Chlorite bleaching, Dyeing (Acid, Disperse)
Carbonization
pH of textile application
Wetting agent for desizing process
Enzymatic desizing Not deactivate enzyme Good detergency Should use nonionic wetting agent
Polyethylene glycol ether Block copolymer EO, PPO ether
Oxidative desizing : should use nonionic or sulphonate anionic type Resistance to persulphate
As Enzymatic desizing Sulphosuccinate derivative
Wetting agent for scouring process
High wetting power Good detergency and emulsifying Not specify the chemical alone Should use the blends of anionic and
nonionic surfactant. Fatty alkyl sulfate, sulfonate and phosphate Ethoxylated fatty alcohol Ethoxylated octyl-/ nonyl- phenol
Wetting agent for bleaching Resistance to oxidising agent
H2O2 resistance Ethoxylated alkyl phenol
Hypochlorite resistance Disodium alkyl diphenyl ether Sodium alkane sulfonate
Chlorite resistance EO of short chain carbon alcohol EO of alkylphenol EO + anionic surfactant
Wetting agent for carbonising process Resistance the mineral acid condition
Nonionic surfactant Sulfonated anionic surfactant
Wetting agent for mercerisation Resistance to strongly alkaline Small hydrophobic group and good alkaline
solubility Phenol derivative Blends of ethyl hexanol sulfate with organic solvent Short-chain alkylphosphonate esters
Conventional wetting agent(insoluble in concentrated alkaline)
Wetting agent for mercerisation
soluble in concentrated alkaline
poor wetting in neutral
still wetting property in alkaline
Rewetting agent
Promote wetting property of substrate after drying
Not necessary to good wetting propertyAnionic surfactantHigh EO unit nonionic surfactant
Scouring agent :
Factor for scouring
Scouring
Effects of scouring agent
Mechanical effect involved in washing
Wetting/Penetrating effect Emulsifying/dispersingSolubilizing effect Detergency Foaming effect Other effects
Structural propose for scouring agent Longer chain hydrophobic with remaining
soluble Linear hydrophobic part End position of hydrophilic part Cloud point is slightly higher than process
temperature (non-ionic) Optimum EO unit (different for hydrophobic part) Ionic head group can increase the detergency of
PEO surfactant (e.g. Laureth sulfate) Not adsorb on the fiber
Schematic of Scouring process
(a) Surface covered with greasy dirt.
(b) Surfactant is added to the solution. It reduce adhesion of dirt to the surface when deposited with hydrophobic tails on the surface.
(c) Dirt particle are held as a suspension.
Mechanism for greasy dirt removal from substrate
(a) Roll-up
(b) Emulsification
(c) Solubilisation
Example of scouring agent with variation of typesDetergent % Detergency
Sodium salts of sulfuric ester of higher alcohol 35.3
Lauryl diethanolamide (1:2 type) 48.4
Blends of above detergent 46.0
10 mole EO adducts of nonylphenol 47.0 0.3% solution of each chemical % Detergency = [(A – B)/(C – B)] x 100
Where A = Reflectant of soiled fabric after wash B = Reflectant of soiled fabric before wash
C = Reflectant of white fabric• Standard soiled solution contained
1 part Fully hydrogenated tallow3 parts Liquid paraffin0.8 part Carbon black800 parts Carbon tetrachloride
Emulsifying & Dispersing agent :
Distinguish of term
Emulsifying agent (Emulsifier)Agent for help immiscibility liquid/liquid to
uniformly distribute in each phase (liquid/liquid)
Dispersing agentAgent for help uniformly distribute of solid in
liquid phase (solid/liquid)
Emulsifying agent
High HLB values use for O/W emulsion Low HLB values use for W/O emulsion Mix of 2 or 3 emulsifiers can gave
emulsion stability than those of single useAll of type of surfactant can be used for
emulsifier depends on liquid/liquid phase
Schematic of anionic emulsion (O/W)
Dispersing agent
Dispersing agent for disperse dyes Anionic dispersing agent
Naphthalene sulfonate Lignin sulfonate
Nonionic dispersing agent Higher EO alcohol ethoxylate Higher EO non-ionic surfactant
Typical anionic dispersing agent
Napthalene sulfonate
Lignin sulfonate
Model of the disperse dye system
Dispersion thermal stability on dispersing agent structure
Levelling agent :Levelness
Unlevelness
Main mechanisms of levelling agents
Nonionic agents Usually form water-soluble complexes with the dye,
some degree of solubilisation being involved
Ionic agents Dye-substantive
Form complexes with the dye and there is competition between the levelling agent and the fibre for the dye
Fibre-substantive competition between levelling agent and the dye for the fibre
Levelling agent types and their uses
Levelling agent for acid dyes
Cationic levelling agent
Anionic levelling agent
Schematic representation of solubilised acid dye-agent complex
Mechanism of levelling for acid dyes
Dye-SO3-
C
O
N
H
N+H3
Dye-SO3-
C
O
N
H
N+H3
Levelling-SO3-
C
O
N
H
N+H3
Levelling-SO3-
C
O
N
H
N+H3
Dye-SO3-
Levelling-N+R4
Dye-SO3-
Levelling-N+R4
Dye-SO3-
C
O
N
H
N+H3
Dye-SO3-Levelling-SO3
-
Nylon
1. Complex dye-levelling
2. Competitive anionic levelling
Splitting out
Splitting out
Levelling agent for disperse dyes
Non-ionic levelling agent tend to be separated at high temperature but can increase dyes solubilisation (Low cloud point)
Anionic levelling agent can increase the cloud point of nonionic agent
Should synergistic mixing together 7-10% of B in A can increase cloud point of A alone
(105oC) to 150oC Fully effective at pH >7 (Carefully selection of dyes)
(A) fatty acid ethoxylate (B) sodiumdodecylbenzenesulphonate
Levelling agent for disperse dyes
Modified nonionic (or Modified anionic, Weakly anionic) Phosphate ester ethoxylation
High temperature stability Protect hardness and trace metal ion Stabilise under high concentration of electrolyte Fully effective at pH 4-5 (pH of disperse dyeing)
Levelling agent for disperse dyes
Oligo-soaps or Ethoxylated multi-ester compounds.
More stable dye dispersion at high temperature Solubilisation take place at a lower temperature Dyeing rate at lower temp. is much slower Solubilisation of oligomer and acrylic size Low foaming
Defoaming agent :
Foam breaking mechanism
Typical defoaming agent
Organic based defoamers Relatively poor foam control Some tend to leave deposit on machine Example is propylene-1,2-glycol
mononeodecanoate
Typical defoaming agent
Silicone based defoamers High efficiency for controlling the foam If the emulsion use not suitable emulsifier,
Silicone spot is usually occur. Example is ethoxylated polydimethyl siloxane
Conclusion : Surfactant auxiliary
Surfactant contain the balancing of hydrophilic part and hydrophobic part.
CMC and Cloud point of surfactants can indicate their application and property.
Surfactant usually locate at interphase. Ionicity of surfactant is the important
function for choosing.
