Template polymerisation and co-polymerisation

Concepts of a synthetic minimal cell: Information molecules, metabolic pathways, and vesicle reproduction

How do the living systems emerge from non-living molecular assemblies? What physical and chemical principles supported the process? To address these questions, a promising strategy is to artificially reconstruct living cells in a bottom-up way. Recently, the authors developed the "synthetic minimal cell" system showing recursive growth and division cycles, where the concepts of information molecules, metabolic pathways, and cell reproduction were artificially and concisely redesigned with the vesicle-based system. We intentionally avoided using the sophisticated molecular machinery of the biological cells and tried to redesign the cells in the simplest forms. This review focuses on the similarities and differences between the biological cells and our synthetic minimal cell concerning each concept of cells. Such comparisons between natural and artificial cells will provide insights on how the molecules should be assembled to create living systems to the wide readers in the field of synthetic biology, artificial cells, and protocells research. This review article is an extended version of the Japanese article "Growth and division of vesicles coupled with information molecules," published in SEIBUTSU-BUTSURI vol. 61, p. 378-381 (2021).

Nucleic-Acid-Templated Synthesis of Smart Polymer Vectors for Gene Delivery

Nucleic acids are information-rich and readily available biomolecules, which can be used to template the polymerization of synthetic macromolecules. Here, we highlight the control over the size, composition, and sequence one can nowadays obtain by using this methodology. We also highlight how templated processes exploiting dynamic covalent polymerization can, in return, result in therapeutic nucleic acids fabricating their own dynamic delivery vector - a biomimicking concept that can provide original solutions for gene therapies.

Interpolymer Complexes Based on Cellulose Ethers: Application

Interpolymer complexes based on cellulose ethers have gained significant interest in recent years due to their versatile applications. These complexes are formed by combining different polymers through non-covalent interactions, resulting in stable structures. This article provides an overview of the various fields where IPCs based on cellulose ethers find application. IPCs based on cellulose ethers show great potential in drug delivery systems. These complexes can encapsulate drugs and enable controlled release, making them suitable for sustained drug delivery. They offer advantages in terms of precise dosage and enhanced therapeutic efficacy. Coatings and adhesives also benefit from IPCs based on cellulose ethers. These complexes can form films with excellent mechanical strength and enhanced water resistance, providing durability and protection. They have applications in various industries where coatings and adhesives play a crucial role. In food packaging, IPCs based on cellulose ethers are highly relevant. These complexes can form films with effective barrier properties against oxygen and water vapor, making them ideal for packaging perishable foods. They help extend to shelf life of food products by minimizing moisture and oxygen transfer. Various methods, such as solvent casting, coacervation, and electrostatic complexation, are employed to synthesize IPCs based on cellulose ethers.

Preparation of amphiphilic cationic polyacrylamide (CPAM) with cationic microblock structure to enhance printing and dyeing sludge dewatering and condition performance

Flocculation is an important pretreatment technology for sludge dewatering, and the flocculant's performance is the key factor to determine the flocculation effect. Cationic polyacrylamide (CPAM) is commonly used in dewatering and conditioning of printing and dyeing sludge (PD sludge), and the research of high-efficiency flocculant is a hot spot in the field of PD sludge dewatering. Hydrophobic butylacrylate (BA) and (2-(Methacryloyloxy)ethyl) trimethylammonium chloride (DMC) were introduced into the copolymer, and amphiphilic (hydrophilic/lipophilic) CPAM, namely TP-ADB, with microblock structure was synthesized by ultrasonic initiated template copolymerization in this study. The functional group composition of TP-ADB was determined by FTIR and ¹H NMR. Thermogravimetric analysis (TGA) showed that TP-ADB had good thermal stability. The amphiphilic rheological properties of the copolymer were measured according to the apparent viscosity. In addition, ¹H NMR and TGA results confirmed the existence of microblock structure in the copolymer chain. The polymerization mechanism was discussed by association coefficient (K_M) measurement. The results showed that the template copolymerization initiated by ultrasonic followed the law of free radical copolymerization. The pre-adsorption of DMC with sodium polyacrylate template (NaPAA) before the reaction confirmed that the template polymerization accorded with ZIP I mechanism. The cationic microblock structure and hydrophobic association of TP-ADB promoted the dewatering performance of PD sludge (FCMC = 72.9%, turbidity removal rate = 98.9%, SRF = 4.2 × 10¹² m·kg^-1). Hydrophobic association enhanced the bridging, sweeping, and net catching effect, and promoted the growth of floc size and fractal dimension. Cationic microblock structure can produce compact floc with higher mechanical strength by enhancing electrical neutralization and electrical patching. As a skeleton, the compressibility of filter cake was reduced and the permeability was enhanced, and the PD sludge dewatering effect was significantly improved.

Switchable Electrostatically Templated Polymerization

We report a switchable, templated polymerization system where the strength of the templating effect can be modulated by solution pH and/or ionic strength. The responsiveness to these cues is incorporated through a dendritic polyamidoamine-based template of which the charge density depends on pH. The dendrimers act as a template for the polymerization of an oppositely charged monomer, namely sodium styrene sulfonate. We show that the rate of polymerization and maximum achievable monomer conversion are directly related to the charge density of the template, and hence the environmental pH. The polymerization could effectively be switched "ON" and "OFF" on demand, by cycling between acidic and alkaline reaction environments. These findings break ground for a novel concept, namely harnessing co-assembly of a template and growing polymer chains with tunable association strength to create and control coupled polymerization and self-assembly pathways of (charged) macromolecular building blocks.

Template-Directed Synthesis of Bivalent, Broad-Spectrum Hosts for Neuromuscular Blocking Agents*

We report on the synthesis of bivalent water-soluble calix[4]arene and calix[5]arene hosts, Super-sCx4 and Super-sCx5 as new broad-spectrum supramolecular binders of neuromuscular blocking agents (NMBAs). Synthesis was achieved using the target bisquaternary amine NMBAs as a template to link two highly anionic p-sulfonatocalixarene building blocks in aqueous solution. Bivalent anionic hosts Super-sCx4 and Super-sCx5 bind by engaging both quaternary amines present on a variety of NMBAs. We report low μM binding to structurally diverse alkyl, steroidal, curarine and benzylisoquinoline NMBAs with high selectivity over the neurotransmitter acetylcholine and a variety of other hydrophobic amines.

Templated approach to well-defined, oxidatively coupled conjugated polymers

Templated oxidative polymerization affords organic soluble, oxidatively doped PEDOT-based polymers with controlled molecular weights and low dispersities (Đ ∼ 1.2) for the first time.

Gamma radiation-induced preparation of chitosan-acrylic acid-1-vinyl-2-vinylpyrrolidone/multiwalled carbon nanotubes composite for removal of 152+154Eu, 60Co and 134Cs radionuclides

Removal behaviors of ^152+154Eu, ⁶⁰Co, and ¹³⁴Cs radionuclides onto Chitosan-acrylic acid-1-vinyl-2-vinylpyrrolidone/oxidized multi-walled carbon nanotubes (CTS-AA-VP/o-MWCNTs) composite has been investigated by batch adsorption technique. CTS-AA-VP/o-MWCNTs composite has been synthesized by copolymerization of acrylic acid (AA) and 1-vinyl-2-vinylpyrrolidone (VP) onto the surface of chitosan/oxidized multi-walled carbon nanotubes (CTS/o-MWCNTs) using gamma radiation. SEM, TGA, and FTIR were applied to characterize the morphology, thermal stability, and structure of the composite. The composite shows high removal capacity of 321.77, 369.91, and 456.46 mg/g towards ^152+154Eu, ⁶⁰Co, and ¹³⁴Cs radionuclides, respectively.

Urea-Based Imprinted Polymer Hosts with Switchable Anion Preference

The design of artificial oxyanion receptors with switchable ion preference is a challenging goal in host–guest chemistry. We here report on molecularly imprinted polymers (MIPs) with an external phospho-sulpho switch driven by small molecule modifiers. The polymers were prepared by hydrogen bond-mediated imprinting of the mono- or dianions of phenyl phosphonic acid (PPA), phenyl sulfonic acid (PSA), and benzoic acid (BA) using N-3,5-bis-(trifluoromethyl)-phenyl-Ń-4-vinylphenyl urea (1) as the functional host monomer. The interaction mode between the functional monomer and the monoanions was elucidated by ¹H NMR titrations and ¹H–¹H NMR NOESY supported by molecular dynamic simulation, which confirmed the presence of high-order complexes. PPA imprinted polymers bound PPA with an equilibrium constant K_eq = 1.8 × 10⁵ M^–1 in acetonitrile (0.1% 1,2,2,6,6-pentamethylpiperidine) and inorganic HPO₄^2– and SO₄^2– with K_eq = 2.9 × 10³ M^–1 and 4.5 × 10³ M^–1, respectively, in aqueous buffer. Moreover, the chromatographic retentivity of phosphonate versus sulfonate was shown to be completely switched on this polymer when changing from a basic to an acidic modifier. Mechanistic insights into this system were obtained from kinetic investigations and DSC-, MALDI-TOF-MS-, ¹H NMR-studies of linear polymers prepared in the presence of template. The results suggest the formation of template induced 1–1 diad repeats in the polymer main chain shedding unique light on the relative contributions of configurational and conformational imprinting.

100th Anniversary of Macromolecular Science Viewpoint: Toward Artificial Life-Supporting Macromolecules

Terrestrial Life is based on polymers. In all known living organisms, DNA stores genetic information, mutates, self-replicates, and guides the synthesis of messenger molecules. Although the function of nucleic acids is well-understood, the development of artificial macromolecular mimics remains very limited. Laboratory-synthesized nucleic acids still support Life, and some nucleic acids analogues exhibit biological functions. Yet, after hundred years of polymer science, no other type of Life-supporting macromolecule (i.e., non-nucleic acids) has ever been reported. In this context, the aim of the present viewpoint is to discuss important challenges that shall be addressed by polymer chemists to achieve artificial Life. Similarly to DNA, an artificial Life-supporting macromolecule shall store information, transfer information, and mutate. Many tools, such as sequence-defined polymer synthesis, polymer modification, supramolecular polymer chemistry, and dynamic chemistry, are already available to chemists to attain these properties. However, the design of artificial Life-supporting macromolecules is hindered by two main factors. First, the chemical search space is enormous, and it is difficult to predict promising structures, even with the help of combinatorial and chemoinformatic tools. Second, rational design is probably a limited approach to achieve macromolecules that shall be involved in nonequilibrium metabolic systems. Hence, a synergic combination of classical polymer chemistry with the more recent field of systems chemistry is probably the key toward the emergence of artificial Life-supporting macromolecules.

Responsive Hydrogel-based Photonic Nanochains for Microenvironment Sensing and Imaging in Real Time and High Resolution

Microenvironment sensing and imaging are of importance in microscale zones like microreactors, microfluidic systems, and biological cells. But they are so far implemented only based on chemical colors from dyes or quantum dots, which suffered either from photobleaching, quenching, or photoblinking behaviors, or from limited color gamut. In contrast, structural colors from hydrogel-based photonic crystals (PCs) may be stable and tunable in the whole visible spectrum by diffraction peak shift, facilitating the visual detection with high accuracy. However, the current hydrogel-based PCs are all inappropriate for microscale detection due to the bulk size. Here we demonstrate the smallest hydrogel-based PCs, responsive hydrogel-based photonic nanochains with high-resolution and real-time response, by developing a general hydrogen bond-guided template polymerization method. A variety of mechanically separated stimuli-responsive hydrogel-based photonic nanochains have been obtained in a large scale including those responding to pH, solvent, and temperature. Each of them has a submicrometer diameter and is composed of individual one-dimensional periodic structure of magnetic particles locked by a tens-of-nanometer-thick peapod-like responsive hydrogel shell. Taking the pH-responsive hydrogel-based photonic nanochains, for example, pH-induced hydrogel volume change notably alters the nanochain length, resulting in a significant variation of the structural color. The submicrometer size endows the nanochains with improved resolution and response time by 2-3 orders of magnitude than the previous counterparts. Our results for the first time validate the feasibility of using structural colors for microenvironment sensing and imaging and may further promote the applications of responsive PCs, such as in displays and printing.

Augmented polyhydrazone formation in water by template-assisted polymerization using dual-purpose supramolecular templates

Template-assisted polymerization using donor–acceptor supramolecular templates results in higher M_w and M_n values, decreased critical hydrogelation concentrations, and increased gel recovery velocity following shear-induced breakdown.

Precise Generation of Selective Surface-Confined Glycoprotein Recognition Sites

Since glycoproteins have become increasingly recognized as key players in a wide variety of disease processes, there is an increasing need for advanced affinity materials for highly selective glycoprotein binding. Herein, for the first time, a surface-initiated controlled radical polymerization is integrated with supramolecular templating and molecular imprinting to yield highly reproducible synthetic recognition sites on surfaces with dissociation constants (K D) in the low micromolar range for target glycoproteins and minimal binding to nontarget glycoproteins. Importantly, it is shown that the synthetic strategy has a remarkable ability to distinguish the glycosylated and nonglycosylated forms of the same glycoprotein, with a >5-fold difference in binding affinity. The precise control over the polymer film thickness and positioning of multiple carbohydrate receptors plays a crucial role in achieving an enhanced affinity and selectivity. The generated functional materials of unprecedented glycoprotein recognition performance open up a wealth of opportunities in the biotechnological and biomedical fields.

Effect of Template Type on the Trametes versicolor Laccase-Catalyzed Oligomerization of the Aniline Dimer p-Aminodiphenylamine (PADPA)

Many previous studies have shown that (i) the oxidation of aniline or the aniline dimer p-aminodiphenylamine (PADPA) in a slightly acidic aqueous solution can be catalyzed with heme peroxidases or multicopper laccases and that (ii) subsequent reactions lead to oligomeric or polymeric products, which resemble chemically synthesized polyaniline in its conductive emeraldine salt form (PANI-ES), provided that (iii) an anionic "template" is present in the reaction medium. Good templates are anionic polyelectrolytes, micelles, or vesicles. Under optimal conditions, their presence directs the reactions in a positive way toward the desired formation of PANI-ES-type products. The effect of four different types of anionic templates on the formation of PANI-ES-like products from PADPA was investigated and compared by using Trametes versicolor laccase (TvL) as a catalyst in an aqueous pH 3.5 solution at room temperature. All four templates contain sulfonate groups: the sodium salt of the polyelectrolyte sulfonated polystyrene (SPS), micelles from sodium dodecylbenzenesulfonate (SDBS), vesicles from a 1:1 molar mixture of SDBS and decanoic acid, and vesicles from sodium bis(2-ethylhexyl)sulfosuccinate (AOT). Although with all four templates, stable, inkjet-printable solutions or suspensions consisting of PANI-ES-type products were obtained under optimized conditions, considerably higher amounts of TvL were required with SDBS micelles to achieve comparable monomer conversion to PANI-ES-like products during the same time period when compared to those with SPS or the two types of vesicles. This makes SDBS micelles less attractive as templates for the investigated reaction. In situ UV/vis/near-infrared, electron paramagnetic resonance (EPR), and Raman spectroscopy measurements in combination with an high-performance liquid chromatography analysis of extracted reaction products, which were deprotonated and chemically reduced, showed seemingly small but significant differences in the composition of the mixtures obtained when reaching reaction equilibrium after 24 h. With the two vesicle systems, the content of unwanted substituted phenazine units was lower than in the case of SPS polyelectrolyte and SDBS micelles. The EPR spectra indicate a more localized, narrower distribution of electronic states of the paramagnetic centers of the PANI-ES-type products synthesized in the presence of the two vesicle systems when compared to that of the similar products obtained with the SPS polyelectrolyte and SDBS micelles as templates. Overall, the data obtained from the different complementary methods indicate that with the two vesicle systems structurally more uniform (regular) PANI-ES-type products formed. Among the two investigated vesicle systems, for the investigated reaction (oxidation of PADPA with TvL and O2), AOT appears a somewhat better choice as it leads to a higher content of the PANI-ES polaron form.

Using ultrasonic (US)-initiated template copolymerization for preparation of an enhanced cationic polyacrylamide (CPAM) and its application in sludge dewatering

In this study, the ultrasonic (US)-initiated template copolymerization was employed to synthesize a novel cationic polyacrylamide (CPAM) characterized by a microblock structure using dimethyldiallylammonium chloride (DMDAAC) and acrylamide (AM) as monomers, and sodium polyacrylate (NaPAA) as template. The polymers structure property was analyzed by Fourier transform infrared spectroscopy (FT-IR), ¹H nuclear magnetic resonance spectroscopy (¹H NMR) and thermogravimetric analysis (TGA). The results showed that a novel cationic microblock structure was successfully synthesized in the template copolymer of DMDAAC and AM (TPADM). Meanwhile, the analysis result of association constant (M_K) provided powerful support for a I Zip-up (ZIP) template polymerization mechanism and the formation of the microblock structure. The factors affecting the polymerization were investigated, including ultrasonic power, ultrasonic time, monomer concentration, initiator concentration, m_AM:m_DMDAAC and n_NaPAA:n_DMDAAC. The sludge dewatering performance of the polymers was evaluated in terms of specific resistance to filtration (SRF), filter cake moisture content (FCMC), floc size (d₅₀) and fractal dimension (D_f). Flocculation mechanism was also analyzed and discussed. The sludge dewatering results revealed that the polymer with the novel microblock structure showed a more excellent flocculation performance than those with randomly distributed cationic units. A desirable flocculation performance with a SRF of 4.5 × 10¹² m kg^-1, FCMC of 73.1%, d₅₀ of 439.156 µm and D_f of 1.490 were obtained at pH of 7.0, dosage of 40 mg L^-1 and the molecular weight of 5.0 × 10⁶ Da. The cationic microblock extremely enhanced the polymer charge neutralization and bridging ability, thus obtaining the excellent sludge dewatering performance.

An artificial molecular machine that builds an asymmetric catalyst

Biomolecular machines perform types of complex molecular-level tasks that artificial molecular machines can aspire to. The ribosome, for example, translates information from the polymer track it traverses (messenger RNA) to the new polymer it constructs (a polypeptide) ¹ . The sequence and number of codons read determines the sequence and number of building blocks incorporated into the biomachine-synthesized polymer. However, neither control of sequence^2,3 nor the transfer of length information from one polymer to another (which to date has only been accomplished in man-made systems through template synthesis) ⁴ is easily achieved in the synthesis of artificial macromolecules. Rotaxane-based molecular machines^5-7 have been developed that successively add amino acids^8-10 (including β-amino acids ¹⁰ ) to a growing peptide chain by the action of a macrocycle moving along a mono-dispersed oligomeric track derivatized with amino-acid phenol esters. The threaded macrocycle picks up groups that block its path and links them through successive native chemical ligation reactions ¹¹ to form a peptide sequence corresponding to the order of the building blocks on the track. Here, we show that as an alternative to translating sequence information, a rotaxane molecular machine can transfer the narrow polydispersity of a leucine-ester-derivatized polystyrene chain synthesized by atom transfer radical polymerization ¹² to a molecular-machine-made homo-leucine oligomer. The resulting narrow-molecular-weight oligomer folds to an α-helical secondary structure ¹³ that acts as an asymmetric catalyst for the Juliá-Colonna epoxidation^14,15 of chalcones.

Ultrasound-initiated synthesis of cationic polyacrylamide for oily wastewater treatment: Enhanced interaction between the flocculant and contaminants

Weak interaction between flocculants and oil is a main bottleneck in the treatment of oil-containing wastewater. To solve this problem, a novel flocculant PAB with cationic micro-block structure and hydrophobic groups of benzene rings was synthesized by ultrasound initiated polymerization technique and applied to remove turbidity and oil from water. To avoid unnecessary addition of reagents in traditional template and micellar copolymerization, surface-active monomer benzyl(methacryloyloxyethyl)dimethylammonium chloride (BMDAC) with self-assembly ability in aqueous solution was employed to synthesize flocculants. The critical association concentration of BMDAC measured by conductivity and surface tension methods was 0.014 mol·L^-1. The results of reactivity ratio, statistical analysis of sequence-length distribution and ¹H NMR provided evidence for the synthesis of copolymer with cationic micro-block. In addition, the apparent viscosity measurement indicated that PAB had an obvious hydrophobic association property. Finally, flocculation tests demonstrated that flocculation performance was greatly improved by adding PAB and the removal rate of oil and turbidity both reached the maximum (87.5% and 92%) at dosage of 40 mg·L^-1 and pH of 7.0. Flocculation mechanism investigation demonstrated that the cooperation of charge neutralization, adsorption bridging, and hydrophobic association effect played an important role. The formed flocs by PAB was large, compact, difficult to break, and easy to regrow because of the enhanced interaction between flocculants and oil. In summary, this study can provide important reference in the design of organic flocculants in oily wastewater treatment applications.

The investigation of the specific behavior of a cationic block structure and its excellent flocculation performance in high-turbidity water treatment

The fabrication of a cationic polyacrylamide (CPAM) with high efficiency and economy has been highly desired in the field of high-turbidity water treatment. This study introduced an ultrasound (US)-initiated template polymerization (UTP) method to develop a novel cationic templated polyacrylamide (TPAA) with a microblock structure. TPAA was prepared using acrylamide (AM) and sodium (3-acrylamidopropyl)trimethylammonium chloride (ATAC) as the monomers and sodium polyacrylate (NaPAA) as the template. Factors that affected polymerization such as the ultrasound power, ultrasound time, initiator concentration, pH, and m_AM : m_ATAC and n_NaPAA : n_ATAC values were investigated. The properties of the polymers were characterized by Fourier transform infrared spectroscopy (FTIR), ¹H nuclear magnetic resonance spectroscopy (¹H NMR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The results indicated the successful formation of a cationic microblock structure in TPAA. In addition, TPAA displayed favorable thermal decomposition properties and a rough and coarse surface morphology, as shown by analyses using TGA and SEM, respectively. Moreover, a zip (type I) template polymerization mechanism was identified via analyses of the association constant (K_M), conversion (C_v) and polymerization rate (R_p). The flocculation performance of the templated copolymer TPAA was evaluated by treating high-turbidity water. According to the results for the zeta potentials and FTIR spectra of the generated flocs, it was indicated that the cationic microblocks in the templated copolymer could greatly enhance its charge neutralization, patching and bridging ability, and therefore excellent flocculation performance (residual turbidity: 5.8 NTU, D_f: 1.89, floc size d₅₀: 608.404 μm and floc kinetic: 15.86 × 10⁻⁴ s⁻¹) for treating high-turbidity water was achieved.

The fabrication of a cationic polyacrylamide (CPAM) with high efficiency and economy has been highly desired in the field of high-turbidity water treatment.

Improvement of Sludge Dewaterability by Ultrasound-Initiated Cationic Polyacrylamide with Microblock Structure: The Role of Surface-Active Monomers

Cationic polyacrylamides have been employed widely to improve sludge dewatering performance, but the cationic units are randomly distributed in the molecular chain, which restricts the further enhancement of dewaterability. Common template technology to prepare block copolymers requiring a huge number of templates reduces the polymer purity and molecular weight. Here, we adopted the surface-active monomer benzyl dimethyl 2-(methacryloyloxy)ethyl ammonium chloride (BDMDAC) to synthesize cationic microblocky polyacrylamide initiated by ultrasound. The reactivity ratio of monomers suggested that novel cationic monomer BDMDAC had higher homopolymerization ability, and was thus more prone to forming a microblock structure. The statistical analysis of sequence-length distribution indicated that the number and length of cationic segments increased in the PAB molecules. In addition, the characteristic results of Fourier transform infrared (FTIR), proton nuclear magnetic resonance (¹H NMR), and thermogravimetric analysis (TGA) provided evidence for the synthesis of copolymer with cationic microblocks. Finally, the results of dewatering tests demonstrated that sludge dewaterability was greatly improved by adding the synthesized novel flocculants, and the sludge-specific resistance to filtration, filter cake moisture content and residual turbidity all reached a minimum (68.7%, 5.4 × 1012 m·kg⁻¹, and 2.6 NTU, respectively) at 40 mg·L⁻¹. The PAB flocs were large, compact, difficult to break, and easy to regrow. Furthermore, PAB was more effective in the removal of protein from soluble extracellular polymeric substances (SEPSs). In summary, this study provides a novel solution to synthesize cationic microblock polyacrylamide for improving sludge dewatering.

UV-initiated template copolymerization of AM and MAPTAC: Microblock structure, copolymerization mechanism, and flocculation performance

Flocculation as the core technology of sludge pretreatment can improve the dewatering performance of sludge that enables to reduce the cost of sludge transportation and the subsequent disposal costs. Therefore, synthesis of high-efficiency and economic flocculant is remarkably desired in this field. This study presents a cationic polyacrylamide (CPAM) flocculant with microblock structure synthesized through ultraviolet (UV)-initiated template copolymerization by using acrylamide (AM) and methacrylamido propyl trimethyl ammonium chloride (MAPTAC) as monomers, sodium polyacrylate (PAAS) as template, and 2,2'-azobis [2-(2-imidazolin-2-yl) propane] dihydrochloride (VA-044) as photoinitiator. The microblock structure of the CPAM was observed through nuclear magnetic resonance (¹H NMR and ¹³C NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) analyses. Furthermore, thermogravimetric/differential scanning calorimetry (TG/DSC) analysis was used to evaluate its thermal decomposition property. The copolymerization mechanism was investigated through the determination of the binding constant M_K and study on polymerization kinetics. Results showed that the copolymerization was conducted in accordance with the I (ZIP) template polymerization mechanism, and revealed the coexistence of bimolecular termination free-radical reaction and mono-radical termination in the polymerization process. Results of sludge dewatering tests indicated the superior flocculation performance of microblock flocculant than random distributed CPAM. The residual turbidity, filter cake moisture content, and specific resistance to filtration reached 9.37 NTU, 68.01%, and 6.24 (10¹² m kg^-1), respectively, at 40 mg L^-1 of template poly(AM-MAPTAC) and pH 6.0. Furthermore, all flocculant except commercial CPAM showed a wide scope of pH application.

Formation of cationic hydrophobic micro-blocks in P(AM-DMC) by template assembly: characterization and application in sludge dewatering

The existence of template did play a role of molecular assembly in the radical polymerization, and the cationic hydrophobic micro-blocks in the polymer slightly improved the sludge dehydration performance.

Enhancement of textile-dyeing sludge dewaterability using a novel cationic polyacrylamide: role of cationic block structures

A novel cationic polyacrylamide (CPAM) with a microblock structure was synthesized through ultrasonic-initiated template copolymerization (UTP) using allyltrimethylammonium chloride (TM) and acrylamide (AM) as monomers, and sodium polyacrylate (NaPAA) as a template.

Ultrasonic-template technology inducing and regulating cationic microblocks in CPAM: characterization, mechanism and sludge flocculation performance

In this study, the ultrasonic-template polymerization technique (UTPT) was used to generate and regulate the distribution of cationic microblocks in a polymer.

Supramolecular Helical Systems: Helical Assemblies of Small Molecules, Foldamers, and Polymers with Chiral Amplification and Their Functions

In this review, we describe the recent advances in supramolecular helical assemblies formed from chiral and achiral small molecules, oligomers (foldamers), and helical and nonhelical polymers from the viewpoints of their formations with unique chiral phenomena, such as amplification of chirality during the dynamic helically assembled processes, properties, and specific functionalities, some of which have not been observed in or achieved by biological systems. In addition, a brief historical overview of the helical assemblies of small molecules and remarkable progress in the synthesis of single-stranded and multistranded helical foldamers and polymers, their properties, structures, and functions, mainly since 2009, will also be described.