Charge Density Rules For Nature-Inspired Materials
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We acknowledge the support of: Perry Group, Dubin Group, Charge Density Rules For Nature-Inspired Materials Hansen Tjo, Sarah L. Perry Department of Chemical Engineering, University of Massachusetts Amherst Polycation (+) Polyanion (-) • Surfactant amphilicity -> flexible environments, e.g., hydrophobic drug encapsulation for release in polar physiological system • Charged micelle isotropy ~ ideal colloidal systems How does molecular chemistry inform coacervate phase behavior? Comple x Coacervation 100μm 100μm 100μm Surfactant Steric Repulsion Effects On Phase Behavior 100μm 100μm Y(-) ~ 0.6 Precipitation Predominates Y(-) ~ 0.8 100μm Spherical Droplets (Coacervates) Y(-) ~ 0.3 100μm L-to-S Phase Transition 100μm Y(-) ~ 0.6 • Increase in Polymer Charge Density Decreases Critical Micelle Surface Charge Density • Increase in neutral surfactant head PEG length effectively decreases micelle surface charge density Taylor et al., Soft Matter, 2016, 12, 9142. Applications: • Drug delivery • Vaccines stabilizers • Sustainable oil recovery Electrostatically driven, associative liquid-liquid phase separation (LLPS) • Charge density studies inform molecular design of polymer-micelle slug injections • High-throughput optimization of slug parameters using porous microfluidic media • Bridging systems chemistry and microfluidic platforms for energy sustainability Adapted from He et al., ACS Crystal Growth & Design, 2020, 20, 1021. PDADMAC-SDS/TX-100 Phase Diagram Surfactant Steric Hindrance Polymer Charge Density Design Rules = No Phase Separation Increasing Micelle Surface Charge Density Surfactant amphilicity forms adsorbed film lowering oil/slug interfacial tension Microfluidic Gradient-Tree Approach Increasing surfactant PEG-length increases (−) of turbidity jump scales with increasing micelle steric repulsion Negative correlation between polymer charge density and • Determined the effects of polymer and micelle charge densities in driving complex coacervation • Charge density design framework can be generalized to broad classes of ionic colloids, e.g., charged proteins, nanoparticles etc. and broaden array of coacervate-based platforms • Further exploration into nanoscale chemistry affects on coacervate mechanical properties for renewable energy applications Polyethylene Glycol (PEG) tail on neutral surfactant head = Well-plate assays for turbidity, optical microscopy, kinetics studies
Transcript of Charge Density Rules For Nature-Inspired Materials
We acknowledge the support of: Perry Group, Dubin Group,
Charge Density Rules For Nature-Inspired MaterialsHansen Tjo, Sarah L. PerryDepartment of Chemical Engineering, University of Massachusetts Amherst
Polycation (+) Polyanion (-)
• Surfactant amphilicity -> flexible environments, e.g.,
hydrophobic drug encapsulation for release in polar
physiological system
• Charged micelle isotropy ~ ideal colloidal systems
How does molecular chemistry inform
coacervate phase behavior?
ComplexCoacervation
100μm
100μm
100μm
Surfactant Steric Repulsion Effects On Phase Behavior
100μm
100μm
Y(-) ~ 0.6
Precipitation Predominates
Y(-) ~ 0.8
100μm
Spherical Droplets
(Coacervates)
Y(-) ~ 0.3
100μm
L-to-S Phase Transition100μm
Y(-) ~ 0.6
• Increase in Polymer Charge
Density Decreases Critical Micelle
Surface Charge Density
• Increase in neutral surfactant
head PEG length effectively
decreases micelle surface charge
density
Taylor et al., Soft Matter, 2016, 12, 9142.
Applications:
• Drug delivery
• Vaccines stabilizers
• Sustainable oil
recovery
Electrostatically driven, associative
liquid-liquid phase separation (LLPS)
• Charge density studies inform molecular design of polymer-micelle slug injections
• High-throughput optimization of slug parameters using porous microfluidic media
• Bridging systems chemistry and microfluidic platforms for energy sustainability
Adapted from He et al., ACS Crystal Growth & Design, 2020, 20, 1021.
PDADMAC-SDS/TX-100 Phase Diagram
Surfactant Steric
Hindrance
Polymer Charge Density
Design Rules
= No Phase Separation
Inc
reas
ing
Mic
elle
Su
rface
Ch
arg
e D
en
sity
Surfactant amphilicity forms
adsorbed film lowering oil/slug
interfacial tension
Microfluidic Gradient-Tree Approach
Increasing surfactant PEG-length
increases 𝒀(−) of turbidity jump
𝒀𝒄 scales with increasing micelle
steric repulsion
Negative correlation
between polymer charge density
and 𝒀𝒄
• Determined the effects of polymer
and micelle charge densities in
driving complex coacervation
• Charge density design framework can
be generalized to broad classes of
ionic colloids, e.g., charged proteins,
nanoparticles etc. and broaden array
of coacervate-based platforms
• Further exploration into nanoscale
chemistry affects on coacervate
mechanical properties for renewable
energy applications
Polyethylene Glycol (PEG) tail on neutral
surfactant head
= 𝒀𝒄
Well-plate assays for turbidity, optical
microscopy, kinetics studies
