pH-Responsive Properties of Hollow Polyelectrolyte Microcapsules Templated on Various Cores

Abstract

Hollow polyelectrolyte microcapsules made of poly(allylamine hydrochloride) and sodium poly(styrene sulfonate), templated on various cores, manganese and calcium carbonate particles or polystyrene latexes, were investigated. The polyelectrolyte multilayers respond to a change of pH, leading to a swelling of the capsules in basic conditions and a further shrinking when the pH is reduced to acidic. The nature of the core and the subsequent dissolution process have an influence on this pH responsiveness, and the structuring effect of tetrahydrofuran on the multilayers has been demonstrated. Increasing the molecular weight of the polymers or the number of layers causes also a rigidification of the structure and modifies the pH response.

Stimuli‐Responsive Multilayered Hybrid Nanoparticle/Polyelectrolyte Capsules

“…In literature several papers have been published describing the swelling and dissolution behavior of polyelectrolyte multilayers from weak polyelectrolytes. [26][27][28] The interactions between the successive layers in the (Au NP / PAH) 4 capsules reported in our present paper are also based on the interactions between a weak polyacid, as the Au NP have carboxyl acid groups on their surface, and a weak polybase (i.e., PAH). Therefore, we were interested to know whether our (Au NP /PAH) 4 capsules exhibited a dual responsive behavior both at low and high pH.…”

Evolution of enzyme catalysts caged in biomimetic gel-shell beads

“…The recovery of the genotype (in the form of high-copy number plasmids) is achieved by disassembly of the polyelectrolyte shell upon short treatment with a solution of pH 12. This pH is higher than the pK a of the polycation, which is thus partly deprotonated, so that the polyelectrolyte complex disintegrates 27 and the plasmid DNA can be recovered from beads by standard gel-extraction (Fig. S7, SI).…”

“…While mirroring the role of a natural cell membrane, a man-made product capture system makes selections under in vitro conditions possible and the degrees of freedom in the design of selection schemes are increased. Multilayer technology provides versatile means of designing functional enclosures with variations in the building block polyelectrolytes 38 , so that GSBs can be used under non-physiological or even extreme conditions: for example, the PAH/PSS (poly(allylaminehydrochloride)/poly(styrene-sulfonate)) system withstands temperatures up to 95 °C 10 , is stable between 2 and pH 11 27 , and capsules can even be filled with organic solvents without losing their integrity 39 . The 'immortalization' of droplets makes GSB compartments also suitable for multi-step processes, in which small molecules can be exchanged, while the bead shell cages proteins and DNA.…”

Selective Synthesis of DOPA and DOPA Peptides by Native and Immobilized Tyrosinase in Organic Solvent

“…[55] Preparation of PSS/PAH micro-capsules: The stepwise assembly of the PSS/PAH multi-layer on the MnCO 3 micro-particles was conducted by using a protocol described elsewhere. [26,56,57] Briefly, PSS and PAH solutions (20 mL, 2 mg mL À1 in 0.5 m NaCl) were alternately added to MnCO 3 particles (40 mg) suspended in H 2 O (1 mL). Each poly-electrolyte layer was adsorbed for 20 min, and the particles were collected by centrifugation and washed with H 2 O three times before the addition of the next layer to remove any polyelectrolytes that remained in the supernatant solution.…”