Similar Degree Of Polymerization Research Articles

Unravelling inulin molecules in food sources using a matrix-assisted laser desorption/ionization magnetic resonance mass spectrometry (MALDI-MRMS) pipeline

Inulin, a polysaccharide characterized by a β-2,1 fructosyl-fructose structure terminating in a glucosyl moiety, is naturally present in plant roots and tubers. Current methods provide average degrees of polymerization (DP) but lack information on the distribution and absolute concentration of each DP. To address this limitation, a reproducible (CV < 10 %) high throughput (<2 min/sample) MALDI-MRMS approach capable of characterizing and quantifying inulin molecules in plants using matched-matrix consisting of α-cyano-4-hydroxycinnamic acid butylamine salt (CHCA-BA), chicory inulin-12C and inulin-13C was developed. The method identified variation in chain lengths and concentration of inulin across various plant species. Globe artichoke hearts, yacón and elephant garlic yielded similar concentrations at 15.6 g/100 g dry weight (DW), 16.8 g/100 g DW and 17.7 g/100 g DW, respectively, for DP range between 9 and 22. In contrast, Jerusalem artichoke demonstrated the highest concentration (53.4 g/100 g DW) within the same DP ranges. Jerusalem artichoke (DPs 9–32) and globe artichoke (DPs 9–36) showed similar DP distributions, while yacón and elephant garlic displayed the narrowest and broadest DP ranges (DPs 9–19 and DPs 9–45, respectively). Additionally, qualitative measurement for all inulin across all plant samples was feasible using the peak intensities normalized to Inulin-13C, and showed that the ratio of yacón, elephant garlic and Jerusalem was approximately one, two and three times that of globe artichoke. This MALDI-MRMS approach provides comprehensive insights into the structure of inulin molecules, opening avenues for in-depth investigations into how DP and concentration of inulin influence gut health and the modulation of noncommunicable diseases, as well as shedding light on refining cultivation practices to elevate the beneficial health properties associated with specific DPs.

Mechanochemistry in Block Copolymers: New Scission Site due to Dynamic Phase Separation.

Mechanochemistry can lead to the degradation of the properties of covalent macromolecules. In recent years, numerous functional materials have been developed based on block copolymers (BCPs), however, like homopolymers, their chains could undergo mechanochemical damage during processing, which could have crucial impact on their performance. To investigate the mechanochemical response of BCPs, multiple polymers comprising different ratios of butyl acrylate and methyl methacrylate were prepared with similar degree of polymerization and stressed in solution via ultrasonication. Interestingly, all BCPs, regardless of the amount of the methacrylate monomer, presented a mechanochemistry rate constant similar to that of the methacrylate homopolymer, while a random copolymer reacted like the acrylate homopolymer. Size-exclusion chromatography showed that, in addition to the typical main peak shift towards higher retention times, a different daughter fragment was produced indicating a secondary selective scission site, situated around the covalent connection between the two blocks. Molecular dynamics modeling using acrylate and methacrylate oligomers were carried out and indicated that dynamic phase separation occurs even in a good solvent. Such non-random conformations can explain the faster polymer mechanochemistry. Moreover, the dynamic model for end-to-end chain overstretching supports bond scission which is not necessarily chain-centered.

Mechanochemistry in Block Copolymers: New Scission Site due to Dynamic Phase Separation

AbstractMechanochemistry can lead to the degradation of the properties of covalent macromolecules. In recent years, numerous functional materials have been developed based on block copolymers (BCPs), however, like homopolymers, their chains could undergo mechanochemical damage during processing, which could have crucial impact on their performance. To investigate the mechanochemical response of BCPs, multiple polymers comprising different ratios of butyl acrylate and methyl methacrylate were prepared with similar degree of polymerization and stressed in solution via ultrasonication. Interestingly, all BCPs, regardless of the amount of the methacrylate monomer, presented a mechanochemistry rate constant similar to that of the methacrylate homopolymer, while a random copolymer reacted like the acrylate homopolymer. Size‐exclusion chromatography showed that, in addition to the typical main peak shift towards higher retention times, a different daughter fragment was produced indicating a secondary selective scission site, situated around the covalent connection between the two blocks. Molecular dynamics modeling using acrylate and methacrylate oligomers were carried out and indicated that dynamic phase separation occurs even in a good solvent. Such non‐random conformations can explain the faster polymer mechanochemistry. Moreover, the dynamic model for end‐to‐end chain overstretching supports bond scission which is not necessarily chain‐centered.

Design of Topology‐Controlled Polyethers toward Robust Cooperative Hydrogen Bonding

AbstractTopology control of polymers is critical for determining their physical properties and potential applications; in particular, topologies that incorporate numerous hydrogen bonding (H‐bonding) donors and acceptors along the polymer chains considerably influence the formation of different inter‐ and intramolecular H‐bonding motifs. In this study, the high‐level control of inter‐ and intramolecular H‐bonding is investigated in topology‐controlled poly(glycidoxy carbonyl benzoic acid)s (PGCs). Three types of topology‐controlled PGCs (i.e., linear, hyperbranched, and branched cyclic structures having a similar degree of polymerization) are prepared by introducing aromatic carboxylic acids into the corresponding polyglycidols (PGs) via quantitative post‐polymerization modification with phthalic anhydride. The obtained three types of PGCs demonstrated the high‐level interplay between the inter‐ and intramolecular H‐bonding in polymer chains by exhibiting the pH‐dependent self‐association properties in the solution state and the strong adhesion properties in the bulk state with high transparency. Interestingly, the dramatically enhanced adhesive property by 2.6‐fold is demonstrated by simple mixing of branched cyclic PGC and topology‐controlled PGs to promote the cooperative H‐bonding between polymer chains. The new class of cooperative H‐bonding is anticipated between topology‐controlled polymers to contribute to the development of advanced adhesive and the high potential in biological and biomedical applications due to its excellent biocompatibility.

Utilization of bamboo as biorefinery feedstock: Co-production of xylo-oligosaccharide with succinic acid and lactic acid

Herein, we investigated the possibility of co-producing xylo-oligosaccharides (XOSs) from bamboo, as value-added products, along with succinic and lactic acids, as platform chemicals. Xylan was extracted from bamboo using the alkali method under mild conditions. From xylan, XOSs were produced by partial enzymatic hydrolysis at a conversion rate of 83.9%, and all reaction conditions resulted in similar degrees of polymerization. Hydrogen peroxide-acetic acid (HPAC) pretreatment effectively removed lignin from NaOH-treated bamboo, and the enzymatic hydrolytic yield of NaOH and HPAC-treated bamboo was 84.3% of the theoretical yield. The production of succinic and lactic acids from the hydrolysate resulted in conversion rates of approximately 63.2% and 91.3% of the theoretical yield using Corynebacterium glutamicum Δldh and Actinobacillus succinogenes, respectively, under facultative anaerobic conditions. This study demonstrates that bamboo has a high potential to produce value-added products using a biorefinery process and is an alternative resource for compounds typically derived from petroleum.

Simultaneous Synthesis and Self-Assembly of Bottlebrush Block Copolymers at Room Temperature via Photoinitiated RAFT Dispersion Polymerization.

Bottlebrush polymers exhibiting unique properties have attracted considerable attention for applications in many research areas. Herein, the first simultaneous synthesis and self-assembly of bottlebrush block copolymers at room temperature via photoinitiated polymerization-induced self-assembly (photo-PISA) using multifunctional macromolecular chain transfer agents (macro-CTAs) is reported. Comparing with linear block copolymers, the bottlebrush block copolymers can promote the formation of higher-order morphologies (e.g., vesicles) when targeting similar degrees of polymerization (DPs). Moreover, a higher polymerization rate is observed in the case of bottlebrush block copolymers. Gel permeation chromatography (GPC) analysis shows that good polymerization control is maintained when synthesizing bottlebrush block copolymers by photo-PISA. Finally, the obtained bottlebrush block copolymer vesicles are used as seeds for further chain extension and multicompartment nanoparticles with a sponge internal structure are formed. It is expected that this study will not only expand polymer architectures employed in PISA, but also provide a new strategy to synthesize polymer nanoparticles with unique structures.

Introduction of β-Diketone Unit to Polyfluorene Side Chain for Improving Color Stability and Electron Transporting Property

Abstract Poly[9,9-bis(2,4-octanedionyl)-9′,9′-di-n-octyl[2,2′-bi-9H-fluorene]-7,7′-diyl] (PFOA) was prepared with a β-diketone structure incorporated in the side chain and the optimal octyl length remained. Compared with poly(9,9-di-n-octylfluorene) (PFO) with a similar degree of polymerization, we found that the introduction of β-diketone brought about superior fluorescent, electrochemical and electron transporting properties, which suggested improved color stability and electron mobility.

Facile Synthesis of CO2 -Responsive Nano-Objects: Batch versus Semi-Batch RAFT Copolymerization.

Precise polymer architecture and self-assembled morphological control are attractive due to their promising applications, such as drug delivery, biosensors, tissue engineering and "smart" optical systems. Herein, starting from the same hydrophilic units poly(ethylene glycol) (PEG), using CO2 -sensitive monomer N, N-diethylaminoethyl methacrylate (DEAEMA) and hydrophobic monomer benzyl methacrylate (BzMA), a series of well-defined statistical, block, and gradient copolymers is designed and synthesized with similar degree of polymerization but different monomer sequences by batch and semi-batch RAFT polymerization process and their CO2 -responsive behaviors of these nano-objects is systematically studied. The gradient copolymers are generated by using semi-batch methods with programmed monomer feed rate controlled by syringe pumps, achieving precise control over desired gradient copolymer composition distribution. In aqueous solution, the copolymers could self-assemble into various aggregates before CO2 stimulus. Upon bubbling CO2 , the gradient copolymers preferred to form nanosheet-like structures, while the block and statistical copolymers with similar molar mass could only form larger vesicles with thinner membrane thickness or disassemble. The semi-batch strategy to precisely control over the desired composition distribution of the gradient segment presents an emerging trend for the fabrication and application of stimuli-responsive polymers.

Poly(methyl ethylene phosphate) hydrogels: Degradable and cell-repellent alternatives to PEG-hydrogels

A degradable and water-soluble polyphosphoester (PPE), namely poly(methyl ethylene phosphate)-dimethacrylate (PMEP-DMA), was synthesized and crosslinked by UV irradiation to prepare PPE-hydrogels. Hydrogels with 10 and 15 wt% of PMEP were prepared after UV-irradiation with an additional 0.2 wt% of photoinitiator. The colorless and transparent PPE hydrogels were studied for their swelling and water uptake. The rheological analysis demonstrated their viscoelastic behavior. The PPE hydrogels were compared to poly(ethylene glycol) (PEG) hydrogels prepared from PEG-macromonomers of similar degrees of polymerization. Hydrolysis experiments proved a successful disintegration of the PPE hydrogels compared to PEG analogs; a faster weight loss for the hydrogels with 10 wt% of PMEP compared to the 15 wt% hydrogels was detected. NMR spectroscopy further proved the release of soluble PPEs from the network and the formation of phosphoric acid diesters during the hydrolysis. Finally, the cytotoxicity with the MG-63 osteoblast cell lines and proved low cell toxicity from the hydrogels with no significant cell adherence towards the gels similar to PEG-based hydrogels. In summary, this work proves PMEP-hydrogels as degradable alternatives to PEG-hydrogels with similar hydrophilicity and low cell adhesion, which might be used in further tissue engineering and to prevent polymer accumulation.

Saccharide Characteristics and Their Potential Health Effects in Perspective.

To understand the effects of saccharides on our metabolism and health, we need a clear understanding of what they are, how they differ, and why some types are deemed “less healthy” and others “better for health.” There are various ways to look at this topic. Firstly, saccharides can be classified according to their degree of polymerization (DP). This classification is useful when qualitative or quantitative analysis and calculation of intakes are required or for food-labeling definitions. However, it does not account for the fact that saccharides with a similar DP can differ in molecular composition, which will influence digestion, absorption, and metabolism. Secondly, another approach widely used in the biomedical and nutritional sciences is therefore a physiological classification, which addresses the rate and degree of digestibility and absorption, the glycemic response, and the metabolic fate. The individual health status also plays a role in this respect. An active, lean person will have a metabolic response that differs from an inactive person with overweight and insulin resistance. However, this approach will not give a complete answer either because the characteristics of the matrix/meal in which these carbohydrates (CHOs) are present will also influence the responses of our body. Thirdly, one can also rank CHOs by comparing their functional/technological properties, such as relative sweetness, viscosity, and solubility. Understanding CHO characteristics and related physiological responses will help understand health and disease implications. Therefore, a brief outline of different carbohydrate classifications is presented. This outline will be placed in the context of potential overall effects after consumption. The answer to the question whether we should we eat less of certain sugars depends on the angle from which you look at this matter; for example, do you address this question from a single molecular characteristic point of view or from a meal quality perspective? Looking at one particular CHO characteristic will almost always lead to a different conclusion (e.g., the labeling of fructose as toxic) than evaluating from a “total perspective” (fructose has adverse effects in certain conditions). Examples are given to help understand this matter for the benefit of justified dietary/food-based recommendations.

Effect of surface charge density on the ice recrystallization inhibition activity of nanocelluloses

Recently nanocelluloses have been found to possess ice recrystallization inhibition (IRI) activity, which have several potential applications. The present study focuses on the relationship between the surface charge density (SCD) of nanocelluloses and IRI activity. Cellulose nanocrystals (CNCs) and 2, 2, 6, 6-tetramethylpiperidine-1-oxyl oxidized cellulose nanofibrils (TEMPO-CNFs) with similar degrees of polymerization (DP) or fibril lengths but with different SCDs were prepared and characterized for IRI activity. When the SCD of CNCs was progressively reduced, an initial increase of IRI activity was observed, followed by a decrease due to fibril aggregation. CNCs with a low SCD became IRI active at increased unfrozen water fractions and higher annealing temperatures. TEMPO-CNFs with a low SCD also had higher IRI activity. Additionally, lowering pH to protonate the carboxylate groups of TEMPO-CNFs enhanced the IRI activity. These research findings are important in producing nanocelluloses with enhanced IRI activity and understanding their structure-activity relationship.

Photochemical Polymerization of N-Phenyl Mono-1,3-benzoxazines in Aqueous Media

Some N-phenyl monosubstituted mono-1,3-benzoxazines can be polymerized under appropriate UV irradiation in aqueous solutions at room temperature. Photoinduced intramolecular electron transfer from the amine to the phenyl ring in aqueous media produces the mesolitic O–alkyl bond cleavage governed by “topologically controlled Coulombic interactions”. Irradiation of EWG-substituted benzoxazines produces opening of the oxazine ring as expected, but no propagation of the polymerization is observed probably due to the low nucleophilicity of the intermediate phenolic species. However, with more nucleophilic electron-donor substituted benzoxazines the photopolymerization proceeds smoothly, with excellent conversions and modest degrees of polymerization. The produced materials show a similar degree of polymerization to the observed in the non-cross-linked fraction when monobenzoxazines are polymerized under thermal conditions (>150 °C) but having a lower dispersity.

Cylindrical Micelles with “Patchy” Coronas from the Crystallization-Driven Self-Assembly of ABC Triblock Terpolymers with a Crystallizable Central Polyferrocenyldimethylsilane Segment

Solution self-assembly of a series of linear ABC triblock terpolymers with a central crystallizable poly(ferrocenyldimethylsilane) (PFS) core-forming “B” block and terminal polystyrene (PS) and poly(methyl methacrylate) (PMMA) “A” and “C” blocks has been investigated. Three PS-b-PFS-b-PMMA triblock terpolymers with different block ratios (1, 3.6:1.0:4.7; 2, 7.0:1.0:6.9; and 3, 1.1:1.0:1.4) but with similar degrees of polymerization for the central PFS block were prepared through a combination of living anionic and atom-transfer radical polymerization techniques, together with azide/alkyne “click” chemistry. Cylindrical micelles with a crystalline PFS core were formed in solvents selective for the terminal PS and PMMA blocks. In ethyl acetate, a slightly more selective solvent for the PS block, cylinders with significant microphase separation within the corona in the dry state were observed on the basis of TEM analysis. The use of acetone, which is slightly more selective for the PMMA block than the PS blo...

Synthesis and thermoresponsive properties of OEGylated polypeptide with a LCST at body temperature in water and with a UCST in alcohol or ethanol/water solvent mixture

ABSTRACTThermoresponsive polypeptides bearing oligo(ethylene glycol) (OEG) pendants (i.e., P1‐OEGx and P2‐OEGx, x = 3, 7) were synthesized by copper‐mediated 1,3‐dipolar cycloaddition with high grafting efficiency (≥97%) between side‐chain “clickable” polypeptides, namely poly(γ‐4‐(propargoxycarbonyl)benzyl‐l‐glutamate) (P1) or poly(γ‐4‐(4‐propargoxyphenoxycarbonyl)benzyl‐l‐glutamate) (P2) and azido functionalized OEG (N3‐OEGx). P1 and P2 with similar degree of polymerization (DP = 35 or 37) were prepared from triethylamine initiated ring‐opening polymerization of respective N‐carboxyanhydrides. P1‐OEGx (x = 3, 7) and P2‐OEG7 showed reversible UCST‐type phase transitions in various alcoholic solvents (e.g., ethanol, propanol, n‐butanol, and n‐pentanol). P2‐OEG3 also showed reversible UCST‐type phase transitions in ethanol/water solvent mixtures at the weight percentage of ethanol no less than 50 wt %. P1‐OEG7 and P2‐OEG7 showed reversible LCST‐type phase transitions in aqueous solutions. Variable‐temperature UV–vis spectroscopy revealed that the LCST‐type phase transition temperature (Tpt) of P2‐OEG7 with benzoic acid phenyl ester linkages was at around body temperature and it was barely changed with the variation of polymer concentration, yet it showed noticeable dependence on the nature of salt (i.e., NaCl, NaBr, NaI, or KCl) and salt concentration in the range of 0–300 mM. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 163–173

Carbonation behavior of hydraulic and non-hydraulic calcium silicates: potential of utilizing low-lime calcium silicates in cement-based materials

This paper presents a study on the carbonation behaviors of hydraulic and non-hydraulic calcium silicate phases, including tricalcium silicate (3CaO·SiO2 or C3S), γ-dicalcium silicate (γ-2CaO·SiO2 or γ-C2S), β-dicalcium silicate (β-2CaO·SiO2 or β-C2S), rankinite (3CaO·2SiO2 or C3S2), and wollastonite (CaO·SiO2 or CS). These calcium silicate phases were subjected to carbonation reaction at different CO2 concentration and temperatures. Thermogravimetric analysis (TGA) tests were performed to quantify the amounts of carbonates formed during the carbonation reactions, which were eventually used to monitor the degree of reactions of the calcium silicate phases. Both hydraulic and non-hydraulic calcium silicates demonstrated higher reaction rate in case of carbonation reaction than that of the hydration reaction. Under specific carbonation scenario, non-hydraulic low-lime calcium silicates such as γ-C2S, C3S2 and CS were found to achieve a reaction rate close to that of C3S. Fourier transformed infrared (FTIR) spectroscopy and scanning electron microscope (SEM) tests were performed to characterize the carbonation reaction products of the calcium silicate phases. The FTIR spectra during the early stage of carbonation reaction showed formation of calcium silicate hydrate (C–S–H) from C3S, γ-C2S, β-C2S, and C3S2 phases with a similar degree of polymerization as that of the C–S–H that forms during the hydration reaction of C3S. However, upon further exposure to CO2, these C–S–H phases decompose and eventually converted to calcium-modified (Ca-modified) silica gel phase with higher degree of silicate polymerization. Contradictorily, CS phase started forming Ca-modified silica gel phase even at the early stage of carbonation reaction. This paper also revealed the stoichiometry of the Ca-modified silica gel that formed during the carbonation reaction of the calcium silicate phases using the SEM/energy dispersive spectroscopy (EDS) and TGA results.

Papain-Catalyzed Chemoenzymatic Synthesis of Telechelic Polypeptides Using Bis(Leucine Ethyl Ester) Initiator.

In order to construct unique polypeptide architectures, a novel telechelic-type initiator with two leucine ethyl ester units is designed for chemoenzymatic polymerization. Glycine or alanine ethyl ester is chemoenzymatically polymerized using papain in the presence of the initiator, and the propagation occurs at each leucine ethyl ester unit to produce the telechelic polypeptide. The formation of the telechelic polypeptides is confirmed by (1) H NMR and MALDI-TOF mass spectroscopies. It is revealed by AFM observation that long nanofibrils are formed from the telechelic polyalanine, whereas a conventional linear polyalanine with a similar degree of polymerization shows granule-like structures. The telechelic polyglycine and polyalanine show the crystalline structures of Polyglycine II and antiparallel β-sheet, respectively. It is demonstrated that this method to synthesize telechelic-type polypeptides potentially opens up a pathway to construct novel hierarchical structures by self-assembly.

Diallylbis(3-ethoxycarbonylpropyl)ammonium chloride: A symmetrically substituted monomer for the synthesis of an alternate zwitterionic-anionic cyclopolymer

Diallylbis[(3-ethoxycarbonylpropyl)ammonium chloride] (CH2=CHCH2)2N+[(CH2)3CO2Et]2, a new symmetrical diallyl quaternary ammonium salt, has been cyclopolymerized to its cationic polyelectrolyte (CPE) (+) I having pyrrolidine rings embedded in the polymer backbone. Polymer I would exemplify for the first time a cyclopolymer with each repeating unit bearing two identical 3-carboxypropyl pendants. (CPE) (+) I upon hydrolysis afforded pH-responsive polycationic acid (+) II, which upon successive deprotonation was transformed into a polyzwitterion acid (±) III and polyzwitterion-anion (± -) IV. Because of similar degrees of polymerization for I-IV, a meaningful comparison of their solution properties was possible. While I, II, and IV demonstrated polyelectrolyte like viscosity behavior, (±) III showed anti-polyelectrolyte properties. The anionic portion in (± -) IV controlled its solution properties. Polymer (± -) IV demonstrated remarkable antiscalant behavior; at a concentration of 15 ppm, it inhibited the precipitation of CaSO4 from its supersaturated solution with a scale inhibition efficiency of ≈100% even after 300 min. This study opens up the possibility of using the current polymer as an antiscalant in reverse osmosis plants. Open image in new window

The effects of poly(zwitterions)s versus poly(ethylene glycol) surface coatings on the biodistribution of protein nanoparticles

Zwitterionic poly(carboxybetaine) (PCB), poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and non-ionic poly(ethylene glycol) (PEG), which have similar degrees of polymerization, were grafted to branched polyethyleneimine (PEI) to generate PCB-grafted PEI (PEI-PCB), PMPC-grafted PEI (PEI-PMPC) and PEG-grafted PEI (PEI-PEG) copolymers, respectively. These grafted PEI copolymers with almost the same grafting number were coated on the surface of 110 nm bovine serum albumin-poly(N-3-acrylamidophenylboronic acid) (BSA-PAPBA) nanoparticles to make a comparison of the surface decoration effect on the biodistribution of nanoparticles. Compared to the nanoparticles without surface decoration, surface decoration with the copolymers significantly prolonged the circulation time of BSA-PAPBA nanoparticles, leading to remarkable enhancement of tumor uptake of the nanoparticles. The drug accumulation at the tumor site reached more than 10% injected dose per gram of tumor. Among them, the PEI-PMPC-decorated nanoparticles exhibited the best performance in tumor accumulation and anticancer ability. Thus, these surface-decorated nanoparticles may serve as a strong candidate for high tumor accumulation of drug delivery systems.

Polymethacrylates with Polyhedral Oligomeric Silsesquioxane (POSS) Moieties: Influence of Spacer Length on Packing, Thermodynamics, and Dynamics

Polymethacrylates with polyhedral oligomeric silsesquioxane (POSS) moieties (poly(POSS-MA)s) with flexible spacers between the POSS cages and the methacrylate group have distinctly different properties from their linear counterpart, i.e., PMMA. POSS cages modify interchain correlations and result in multiple dynamic processes that reflect the cooperative relaxations of both the pendant POSS units and ester dipoles and the polymer backbone. As a result, the freezing of the backbone dynamics is shifted to lower temperatures, and the nanocomposites appear softer than linear PMMA chains of similar degrees of polymerization. POSS cages can be employed as nanometer size blocks that, depending on the polymer backbone and the spacer, can impart mobility and control over the mechanical properties of nanocomposites.

Effects of interaction between a polycation and a nonionic polymer on their cross-assembly into mixed micelles.

In this paper, to investigate the effects of interactions between poly(quaternary ammonium) salts (PQAs) and poly(ethylene glycol) on their mixed micellar surface structures and properties under spontaneous conditions, a series of PQAs were first designed and synthesized by atom transfer radical polymerization (ATRP) using 2-(dimethylamino) ethyl methacrylate (DMAEMA) quaternized by bromobutane, bromooctane, and bromododecane, respectively. Poly(poly(ethylene glycol) methyl ether methacrylate) (PPEG) with a similar degree of polymerization was also prepared using poly(ethylene glycol) methyl ether methacrylate by ATRP. Next, these PQAs were mixed with an equal weight of PPEG in water to cross-assemble into mixed micelles. The structures and features of these mixed micelles were characterized by fluorescence measurements, transmission electron microscopy (TEM), dynamic light scattering (DLS), phase analysis light scattering (PALS), proton nuclear magnetic resonance ((1)H NMR), and hydrogen-hydrogen correlation spectroscopy nuclear magnetic resonance (H-H COSY NMR). These results suggest that PQAs and PPEG mixtures can cross-assemble into mixed micelles with low CMC. The surface structures, particle sizes, size distributions, and zeta potentials of PQAs and PPEG mixtures can be tailored by varying the alkyl chain length in quaternary ammonium salts, and the alkyl chain length also influences the distribution and the alkyl chain orientation of quaternary ammonium salts on mixed micelle surfaces. In addition, cytotoxicity of these mixed micelles can be markedly reduced by PPEG compared with their corresponding PQAs, but their good antibacterial activities are still maintained to a certain degree, as evaluated by methyl tetrazolium assay (MTT) and minimum inhibitory concentration (MIC). Our present work provides a new avenue for the preparation of biocompatible and antibacterial materials for biomedical applications.