Copolymer Complexes Research Articles

Customizing Cerium Oxide Particle Synthesis with Hybrid Polyion Complex Templates for Enhanced Oxidation Performance in Photo-Fenton Processes.

Hybrid poly-ion complexes were synthesized through the complexation of a double hydrophilic copolymer with Ce(III) ions. These colloids act as reservoirs for cerium ions, enabling the synthesis of cerium-based Prussian blue nanoparticles with a cubic structure, a narrow size distribution around 100 nm, and good colloidal stability in water. Upon high-temperature calcination, these nanoparticles are transformed into a cerium/iron-based metal oxide catalyst (CeO2/Fe2O3). The resultant composite catalyst demonstrates superior performance in the photo-Fenton oxidation of methylene blue pollutants, achieving a conversion efficiency that rivals other metal-based oxides and cerium-based catalysts.

Numerical representations of AB-type copolymer complexes: analysis of 1H NMR chemical shift patterns in terms of a Smith–Cantor set

When considering the possibility of storing information in the sequence of monomer residues within an AB-type copolymer chain, it is constructive to model that sequence as a string of ones and zeros. The intramolecular environment around any given digit (say a “1”) can then be represented by another string of integers—a code—obtained by summing pairs of digits at equivalent positions, in both directions, from that digit. The code can include only integers 0, 1 and 2, and can represent a number in any base b higher than 2. In base b = 3 the resulting set of codes includes all numbers (because only digits 0, 1 and 2 occur in ternary expansions), but in any base b > 3 the codes define a limited set of numbers comprising a fractal we term a Smith–Cantor set. The 1H NMR spectrum of a random, AB-type co(polyester-imide) shows, on complexation with pyrene, a pattern of complexation shifts approximating very closely to the Smith–Cantor set for which b = 4. Other co(polyimide) complexes show a 1H NMR pattern corresponding to a specific sub-set of this fractal. The sub-set arises from a “stop-at-zero” limitation, whereby digits in the initial string are set to zero for code-generating purposes if they occur beyond a zero, as viewed from the central “1”. The limitation arises in copolymers where pyrene binds by intercalation between pairs of adjacent diimide residues. This numerical approach provides a complete, unifying theory to account for the emergence of fractal character in the 1H NMR spectra of AB-type copolymer complexes.

The copolymerized sulfur coordination-metal complex dye sensitizer exhibiting the highest power conversion efficiency (PCE) 11.78% in dye sensitized solar cells

Polymeric metal complex dyes have been recognized as a significant class of dye sensitizer for optoelectronic applications due to their unique properties. In order to improve the light absorption and photovoltaic performance and to decrease costs, five novel D-A-π-A motif copolymerized sulfur coordination-metal complexes (BDTT-BBT-Ni, BDTT-BBT-Cu, BDTT-BBT-Zn, BDTT-BBT-Cd and BDTT-BBT-Hg) have been designed and synthesized for being used as dye sensitizer. And the photovolataic performance test results show that the highest PCE of the copolymer complex BDTT-BBT-Hg of five copolymers has reached 11.78% and the copolymer dye sensitizers are simple and inexpensive to synthesize and have good solubility. These results provide a new way to develop stable and efficient metal complexes with sulfur coordination dye sensitizers in the future.

Functionalized Amphiphilic Block Copolymers and Complex Emulsions for Selective Sensing of Dissolved Metals at Liquid-Liquid Interfaces.

Increasing contamination in potable water supplies necessitates the development of sensing methods that provide the speed and selectivity necessary for safety. One promising method relies on recognition and detection at the liquid-liquid interface of dynamic complex emulsions. These all-liquid materials transduce changes in interfacial tensions into optical signals via the coupling of their chemical, physical, and optical properties. Thus, to introduce selectivity, it is necessary to modify the liquid-liquid interface with an interfacially stable and selective recognition unit. To this end, we report the synthesis and characterization of amphiphilic block copolymers modified with metal chelators to selectively measure the concentrations of dissolved metal ions. We find that significant reduction in interfacial tensions arises upon quantitative addition of metal ions with high affinity toward functionalized chelators. Furthermore, measurements from UV-vis spectroscopy reveal that complexation of the block copolymers with metal ions leads to an increase in surface excess and surfactant effectiveness. We also demonstrate selective detection of iron(III) cations (Fe3+) on the μM levels even through interference from other mono-, di-, or trivalent cations in complex matrices of synthetic groundwater. Our results provide a unique platform that couples selective recognition and modulation of interfacial behaviors and demonstrates a step forward in the development of the multiplexed sensing device needed to deconvolute the complicated array of contaminants that comprise real-world environmental samples.

Polymer Containing Multiple Secondary Structures—A Competition between Helical Induction and C‐T Complexation

AbstractThough “foldamers” have greatly developed, molecules that fold beyond 2° structures are less common. The design and synthesis of triblock copolymers of the “A‐B‐A” type containing two types of helix formation blocks are presented. Two blocks (A and B) are chosen, with one comprised of L‐polyproline as block “A” and the other block (B) comprised with three naphthalene diimide‐derivatives separated by two proline residues. Block (B) is carefully designed to serve as a bifunctional initiator for the ring‐opening polymerization of proline‐N‐carboxy anhydride as well as to encapsulate an electron‐rich aromatic species by charge transfer complexation (C‐T). As a result of (C‐T) complexation with dialkoxy pyrene, the native helical structure of the middle block is transformed into a 1D columnar structure without affecting the 2° structure of the polyproline block. In this way, the initial helix1‐b‐helix2‐b‐helix1 structure of the block copolymers is transformed into a helix1‐b‐columnar‐b‐helix1 structure. The C‐T complexation and related structural changes of the block copolymers are characterized using UV‐vis, fluorescence, and circular dichroism spectroscopy.

Post-coordination photoinitiated macromolecular thiol-ene coupling reaction for construction of metallo-supramolecular complexes of ABCL2-type miktoarm star copolymers and self-assembly of the complexes in water

In this paper, we focus on investigating synthesis of metallo-supramolecular architectures of ABCL2-type miktoarm star copolymers PCL(-b-PDPA)-b-[(Tpyp)2-b-PMPC] (A, PCL; B, PDPA; C, PMPC; L, Tpyp) with ruthenium(II) (Ru(II)) ions and exploring self-assembly behavior of the complexes in water. Direct coordination of PCL(-b-PDPA)-b-[(Tpyp)2-b-PMPC] to Ru(II) ions and post-coordination photoinitiated macromolecular thiol-ene coupling reaction strategies were explored to construct Ru(II) coordination complexes, respectively. The result indicates that the post-coordination coupling reaction was more suitable strategy for constructing this kind of coordination complexes, which may avoid a larger steric hindrance generated from the coexistence of the three arms of PCL(-b-PDPA)-b-[(Tpyp)2-b-PMPC] leading to the disadvantageous influence on the formation of the bis(terpyridine)-Ru(II) complex. It should be mentioned that, however, although a photoinitiated macromolecular thiol-ene radical coupling reaction is facile, so far to achieve complete reaction of the target groups (i.e., alkene groups) has remained a challenge. Therefore, herein a post-coordination thiol-ene coupling reaction was explored carefully and an appropriate condition for the complete reaction of the alkene groups was given. Interestingly, the Ru(II) coordination complexes could self-assemble to form 2D platelets. This should be attributed to the unique metallo-supramolecular architecture. It is expected that the exploration can provide strategies for construction of complicated and exquisite metallo-supramolecular architectures and novel self-assemblies.

Two-Dimensional Hexagonal Structure of Boron Nitride Nanotubes and BNNT-Induced Phase Transition of Block Copolymer in BNNT/Block Copolymer Complex for Energy Harvesting

Since boron nitride nanotubes (BNNTs) were first manufactured, they have gained considerable attention for their wide-scale application as reinforcing composites, piezoelectric materials, electrical insulating materials, thermal conductors, and neutron shielding materials because of their excellent mechanical, electrical, thermal, and neutron absorption properties. Despite the remarkable properties and broad application scope of BNNTs, their use has been limited because of their ineffective structural control due to the presence of one-dimensional nanoparticles. To overcome this limitation, we investigated an approach for the collective self-assembly of BNNTs by using block copolymers (Pluronic P65 and Pluronic P85) as a template and studied the BNNT-induced phase behavior of the block copolymer. For homogenous mixtures of BNNTs and block copolymers, the BNNTs were encapsulated by the in situ polymerization of surfactants (p-BNNTs), where their overall structures were confirmed by small-angle neutron scattering (SANS) and atomic force microscopy (AFM) measurements. The p-BNNTs were mixed with the block copolymers (at 50%, Pluronic P65 or Pluronic P85) by centrifugation in alternative directions to form homogeneously mixed complexes. Polarized optical microscopy (POM) and small-angle X-ray scattering (SAXS) measurements confirmed a two-dimensional hexagonal structure of the BNNTs in the block copolymer matrix that self-assembled upon heating, which can give a possibility of being used as effective piezoelectric materials for energy harvesting. Moreover, upon the addition of BNNTs, the phase behavior of the block copolymer can be controlled, allowing the formation of hexagonal, face-centered cubic, and body-centered cubic structures depending on the BNNT concentration and temperature. This study provides a new and simple method to control the collective BNNT structure.

Ambient Environment Adaptive Elastomer Constructed by Microphase Separation and Segment Complexation of Triblock Copolymers.

Elastomers with environmental adaption have attracted considerable attention for advanced applications in various areas. Here, we fabricate an ambient environment adaptive elastomer by assembling triblock copolymers polystyrene-b-poly(acrylic acid)-b-polystyrene (SAS) and polystyrene-b-poly(ethylene oxide)-b-polystyrene (SES). Owing to the microphase separation of triblock polymers and hydrogen-bonding complexation of their middle segments, the SAS/SES complex presents dichotomy of vitrified hard PS domains and soft PAA/PEO domains, which presents major relaxation transition in the temperature zone 10-30 °C and relative humidity (RH) 40-60%. The SAS/SES elastomer presents quick adaption to the ambient environment change with temperature and humidity coupling. Moreover, after a loading-unloading cycle training, the SAS/SES elastomer exhibits domain orientation, low energy dissipation, high recovery ratio, and distinct strain stiffening compared with the pristine complex. The SAS/SES elastomer has potential to be used as a sensing and adaption component for complicated intelligent systems.

Enhancing the Antioxidant, Antibacterial, and Wound Healing Effects of Melaleuca alternifolia Oil by Microencapsulating It in Chitosan-Sodium Alginate Microspheres

In this study, antibacterial and antioxidant molecules-rich Melaleuca alternifolia oil (tea tree oil (TTO)) loaded chitosan (CS) based nanoemulsions (NEMs) were prepared and encapsulated by sodium alginate (SA) microsphere for antibacterial wound dressing. CS-TTO NEMs were prepared by oil-in-water emulsion technique, and the nanoparticle tracking analysis (NTA) confirmed that the CS-TTO NEMs had an average particle size of 89.5 nm. Further, the SA-CS-TTO microsphere was confirmed through SEM analysis with an average particle size of 0.76 ± 0.10 µm. The existence of TTO in CS NEMs and SA encapsulation was evidenced through FTIR analysis. The XRD spectrum proved the load of TTO and SA encapsulation with CS significantly decreased the crystalline properties of the CS-TTO and SA-CS-TTO microsphere. The stability of TTO was increased by the copolymer complex, as confirmed through thermal gravimetric analysis (TGA). Furthermore, TTO was released from the CS-SA complex in a sustained manner and significantly inhibited the bacterial pathogens observed under confocal laser scanning microscopy (CLSM). In addition, CS-TTO (100 µg/mL) showed antioxidant potential (>80%), thereby increasing the DPPH and ABTS free radicals scavenging ability of SA-CS-TTO microspheres. Moreover, CS and SA-CS-TTO microsphere exhibited negligible cytotoxicity and augmented the NIH3T3 cell proliferation confirmed in the in vitro scratch assay. This study concluded that the SA-CS-TTO microsphere could be an antibacterial and antioxidant wound dressing.

Complexes of Charged-Neutral Block Copolymers and Surfactants: Process-Dependent Features and Long-Term Stability of Their Aqueous Dispersions

Aqueous dispersions of charged-neutral block copolymers (poly(acrylamide)-b-poly(acrylate)) complexed with an oppositely charged surfactant (dodecyltrimethylammonium) have been prepared by different approaches: the simple mixing of two solutions (MS approach) containing the block copolymer and surfactant, with their respective simple counterions, and dispersion of a freeze-dried complex salt prepared in the absence of simple counterions (CS approach). The CS particles were investigated under different conditions: dispersion of a CS in salt-free water and dispersion of a CS in a dilute salt solution, the latter condition yielding dispersions with the same composition as the MS process. Additionally, aged dispersions (up to 6 months) and dispersed complexes of the polyacrylate homopolymer and dodecyltrimethylammonium surfactant were evaluated. By employing different characterization techniques, it was seen that dispersions prepared by the MS approach display nanometric spherical particles with disordered cores, and poor colloidal stability, partially caused by the absence of surface charge (ζ-potential close to zero). Oppositely, anisometric particles were formed in CS dispersions and were large enough to sustain micellar cubic cores. The CS particles presented long-time colloidal stability, partially due to a net negative surface charge, but the stability varied with the length of the neutral block composing the corona. Our results demonstrate that all dispersed particles are metastable structures, with physicochemical properties strongly dependent on the preparation procedure, thus making these particles suitable for fundamental studies and potential applications where accurate control of their properties, including size, shape, internal structure, and stability, is desired.

L-asparaginase immobilization in supramolecular nanogels of PEG-grafted poly HPMA and bis(α-cyclodextrin) to enhance pharmacokinetics and lower enzyme antigenicity

L-asparaginase (ASNase) enzyme has limited therapeutic use due to its poor pharmacokinetics and immunogenicity. To overcome these obstacles, we immobilized ASNase in biocompatible poly hydroxypropyl methacrylamide (P(HPMA))-based nanogels simply formed through the host-guest inclusion complex of ASNase-conjugated random copolymer of HPMA and polyethylene glycol (PEG) acrylate (P(HPMA-MPEGA)) and α-cyclodextrin dimer (bisCD) using cystamine as a linker. The effects of bisCD and polymer concentrations on particle size, gelation time, and recovery of enzyme activity were investigated. The ASNase-conjugated bisCD nanogels were discrete, homogeneous, and spherical with a mean projected diameter of 148 ± 41 nm. ASNase immobilized in the bisCD nanogels caused cytotoxicity on HL-60 cell line with IC50 of 3 IU/ml. In-vivo rat study revealed that the immobilized ASNase reduced the enzyme antigenicity and resulted in 8.1 folds longer circulation half-life than the native enzyme. Conclusively, immobilization of ASNase in P(HPMA-MPEGA) and bisCD supramolecular nanogels could enhance the therapeutic value of ASNase in cancer chemotherapy.

Sulfonated sodium tannin and AM/AMPS copolymer complex as an anti-temperature viscosity reducer for water-based drilling fluid

ABSTRACT Viscosity reducer is used to reduce the high viscosity of drilling fluid containing bentonite as a continuous phase. However, the viscosity of drilling fluid increases and the rheology of the drilling fluid deteriorates at high temperature, causing problems such as reduction in rate of penetration and bit balling. As a core component, drilling fluids with bad rheology seriously affect the further development of drilling engineering, especially at high temperatures. Therefore, there is an urgent need for viscosity reducer suitable for high temperature. In this study, a high temperature-resistant viscosity reducer for water-based drilling fluid was prepared. The rheological parameters of drilling fluids containing 0, 0.5, 1, 1.5 wt% viscosity reducer after aging at different temperatures were evaluated. The results showed that the rheological parameters, such as apparent viscosity, yield point, plastic viscosity, and gel strength decreased within 200℃. Otherwise, filtration volume of 1.8 and 2.2 g/cm3 compound drilling fluids containing 1 wt% viscosity reducer was less than 10 ml. And its resistance to Na+ contamination reached saturation, that is, 36% NaCl solutions. The mechanism of viscosity reduction was also investigated by Fourier transform infrared and X-ray diffraction. Viscosity reducer adsorbed on the clay particles and destroyed the network structure formed by the clay particles while releasing free water.

Competitive hydrogen bonding induced phase separation in supramolecular comb-shaped diblock copolymer

In this study, a route to prepare nanostructure in miscible diblock copolymers by utilization of competitively intermolecular hydrogen-bonding interactions is demonstrated. Block copolymers poly(4-vinylpyridine-b-4-hydroxybutyl acrylate) (P4VP-b-P4HBA) with various block ratios were synthesized and they were demonstrated to be miscible due to the intramolecular hydrogen bonding. By combination of P4VP-b-P4HBA and 3-pentadecylphenol (PDP), the miscible block copolymer forms comb-shaped di-block copolymer complexes through the competition interactions between the hydroxyl groups of PDP (proton donors) and the nitrogen of the pyridine rings of the P4VP blocks (proton acceptors). Upon blending with PDP, we observed morphology change from sphere structure to cylindrical, and lamellar, in a manner strongly dependent on the P4HBA fraction. The microstructure of this special comb-shaped di-block copolymer shows a strong sensitivity to the temperature. The results from the in situ small angle X-ray scattering experiments have demonstrated that, even below the order-disorder temperature, the size of the phase domain decreases with increasing temperature due to decrease of the strength of the hydrogen bond upon heating.

Inclusion complexes of triblock L35 copolymer and hydroxyl propyl cyclodextrins: a physico-chemical study

Polypseudorotaxanes based on triblock L35 copolymer and hydroxyl propyl-modified cyclodextrins (HP-α-CD and HP-β-CD) have been characterized. Their physico-chemical properties have been correlated to the threading process.

Heterogeneous Charged Complexes of Random Copolymers for the Segregation of Organic Molecules.

Nature harnesses the disorder of intrinsically disordered proteins to organize enzymes and biopolymers into membraneless organelles. The heterogeneous nature of synthetic random copolymers with charged, polar, and hydrophobic groups has been exploited to mimic intrinsically disordered proteins, forming complexes with enzymatically active proteins and delivering them into nonbiological environments. Here, the properties of polyelectrolyte complexes composed of two random copolymer polyelectrolytes are studied experimentally and via simulation with the aim of exploiting such complexes for segregating organic molecules from water. The anionic polyelectrolyte contains hydrophilic and hydrophobic side chains and forms self-assembled hydrophobic domains. The cationic polymer is a high-molecular-weight copolymer of hydrophilic and charged side groups and acts as a flocculant. We find that the polyelectrolyte complexes obtained with this anionic and cationic random copolymer system are capable of absorbing small cationic, anionic, and hydrophobic organic molecules, including perfluorooctanoic acid, a compound of great environmental and toxicologic concern. Importantly, these macroscopic complexes can be easily removed from water, thereby providing a simple approach for organic contaminant removal in aqueous media. MARTINI and coarse-grained molecular dynamics simulations explore how the microscale heterogeneity of these random copolymer complexes relates to their segregation functionality.

NMR spectroscopy of Cu(II) complexes with acrylamide and sodium acrylate copolymer and ω-amino acids

Macromolecular complexes of acrylamide and sodium acrylate copolymer with microelements, including Cu(II), may form at preparation of crop protection and stimulation compositions, where the copolymer serves as an adhesive, water-retaining and film-forming agent. Preparations for crop production may also contain amino acids that protect plants under stressful conditions (cold, dry, etc.). Carboxylic groups of copolymer, carboxylic and amino groups of amino acids may be involved in mixed Cu(II) ions complexes formation. Number of methylene groups separating carboxylic and amino group of amino acids affects its ability to form a stable chelate cycle and, therefore, ligand composition of mixed Cu(II) ions complexes with acrylamide and sodium acrylate copolymer and amino acid. This work is aimed at determining the ligand composition of mixed macromolecular Cu(II) ion complexes with acrylamide and sodium acrylate copolymer and ω-amino acids (β-alanine, γ-aminobutyric acid, ε-aminocaproic acid). 13C and 1H NMR spectroscopy was used to clarify complexes composition. A complex where carboxylic groups of amino acids are ligands has been found to form in aqueous solutions of Cu(II) ions and ω-amino acid (β-alanine, γ-aminobutyric acid, ε-aminocaproic acid) at molar ratio of Cu(II) ions – amino acid equal to 1 : 6. A chelate complex where both carboxylic and amino groups of β-alanine are involved in coordination has been discovered to form in the solution containing Cu(II) ions, β-alanine, as well as acrylamide and sodium acrylate copolymer at molar ratio of Cu(II) – β-alanine – copolymer COO− equal to 1 : 6 : 30. Carboxylic groups of copolymer participate in complex formation as well. Carboxylic groups of both amino acids and the copolymer have been shown to participate in complex formation in aqueous solutions containing Cu(II) ions, either γ-aminobutyric or ε-aminokaproic acid and also acrylamide and sodium acrylate copolymer.

PH-responsive spiropyran-based copolymers and their application in monitoring and antibacterial coatings

Although many multifunctional antibacterial materials have been developed, there are few antibacterial materials that can simultaneously monitor pathogenic bacteria and sterilize efficiently. In this work, pH-responsive spiropyran-based fluorinated copolymers with antibacterial, antifouling and fluorescence performances were prepared. First, the random copolymer of methacrylic acid and 1H,1H,2H,2H-perfluorododecyl acrylate (P(MAA-co-FDA)) were synthesized by RAFT polymerization. Second, spiropyran (SP) was grafted onto P(MAA-co-FDA) to obtain the P(MAA-co-SP-co-FDA) copolymer with fluorescence property. At the third step, the remaining carboxyl groups in the grafted copolymer were complexed with protonated polyhexamethylene biguanidine salt (PHMB) to obtain the P(MAA-co-SP-co-FDA)/PHMB copolymer complex antibacterial materials. The results show that the copolymer complex coatings can effectively inhibit the adhesion of bacteria and release PHMB in a bacterial microenvironment to kill S. aureus and E. coli but remain noncytotoxic. The P(MAA-co-SP-co-FDA) copolymer or its complex with PHMB can open the ring and generate a red fluorescence under acidic conditions produced by bacterial growth and metabolism. In addition, the coatings have good biocompatibility, which may be suitable for medical devices to reduce bacterial infection in vivo and in vitro. The prepared multifunctional materials with excellent anti-adhesion, antimicrobial and fluorescence characters will have a broad application prospect in antibacterial, antifouling and monitoring of medical devices.

Interpolymer Complexes of Star-Shaped Copolymers of Polyoxazoline with the Calixarene Core and Linear Polyacids in Solution

Star-shaped polymers with the calix[8]arene core and poly(2-isopropyl-2-oxazoline) and poly(2-isopropyl-2-oxazoline)–poly[3-(2-oxazoline)propionic acid] block copolymer arms at various ways of attaching blocks to the core are synthesized by ring-opening cationic polymerization. Luminescent labels are introduced by the esterification of carboxyl groups by diazomethane derivatives. In order to obtain interpolymer complexes luminescently labeled poly(methacrylic acid) and poly(acrylic acid) are synthesized. The resulting polymers are characterized by the methods of molecular hydrodynamics and optics. Interpolymer complex formation in the aqueous solutions of the polymers is studied by polarized luminescence. It is shown that the chemical structure of the polyoxazoline fragment and the way of its addition to the core influence the structural and dynamic characteristics of the interpolymer complexes with polycarboxylic acids and their stability.

COMPLEXION OF NONIONIC MACROMOLECULES WITH 3RD METAL IONS OF THE TRANSITION SERIES

The article discusses the formation of complexes between transition metal ions and a copolymer of crotonaldehyde with N-vinylpyrrolidone. Complexation of copolymers with metal ions in solutions has been studied by methods of IR-UV spectroscopy, sedimentation, diffusion and viscosimetry. Coordination of the metal with the copolymer occurs through the oxygen atom of the cycloamide and aldehyde groups.

Sequence of Polyurethane Ionomers Determinative for Core Structure of Surfactant-Copolymer Complexes.

The core of micelles self-assembled from amphiphiles is hydrophobic and contains little water, whereas complex coacervate core micelles co-assembled from oppositely charged hydrophilic polymers have a hydrophilic core with a high water content. Co-assembly of ionic surfactants with ionic-neutral copolymers yields surfactant–copolymer complexes known to be capable of solubilizing both hydrophilic and hydrophobic cargo within the mixed core composed of a coacervate phase with polyelectrolyte-decorated surfactant micelles. Here we formed such complexes from asymmetric (PUI-A2) and symmetric (PUI-S2), sequence-controlled polyurethane ionomers and poly(N-methyl-2-vinylpyridinium iodide)29-b-poly(ethylene oxide)204 copolymers. The complexes with PUI-S2 were 1.3-fold larger in mass and 1.8-fold larger in radius of gyration than the PUI-A2 complexes. Small-angle X-ray scattering revealed differences in the packing of the similarly sized PUI micelles within the core of the complexes. The PUI-A2 micelles were arranged in a more ordered fashion and were spaced further apart from each other (10 nm vs. 6 nm) than the PUI-S2 micelles. Hence, this work shows that the monomer sequence of amphiphiles can be varied to alter the internal structure of surfactant–copolymer complexes. Since the structure of the micellar core may affect both the cargo loading and release, our findings suggest that these properties may be tuned through control of the monomer sequence of the micellar constituents.