Dimethylamino)propyl]methacrylamide Research Articles

Chemiresistive Sensor for Enhanced CO2 Gas Monitoring.

Carbon dioxide (CO2) gas sensing and monitoring have gained prominence for applications such as smart food packaging, environmental monitoring of greenhouse gases, and medical diagnostic tests. Although CO2 sensors based on metal oxide semiconductors are readily available, they often suffer from limitations such as high operating temperatures (>250 °C), limited response at elevated humidity levels (>60% RH), bulkiness, and limited selectivity. In this study, we designed a chemiresistive sensor for CO2 detection to overcome these problems. The sensing material of this sensor consists of a CO2 switchable polymer based on N-3-(dimethylamino)propyl methacrylamide (DMAPMAm) and methoxyethyl methacrylate (MEMA) [P(D-co-M)], and diethylamine. The designed sensor has a detection range for CO2 between 103 and 106 ppm even at high humidity levels (>80% RH), and it is capable of differentiating ammonia at low concentrations (0.1-5 ppm) from CO2. The addition of diethylamine improved sensor performance such as selectivity, response/recovery time, and long-term stability. These data demonstrate the potential of using this sensor for the detection of food spoilage.

Study on the structure-activity relationship of cationic polyacrylates for the treatment of oilfield produced water.

Cationic polyacrylates exhibit both reverse demulsification and flotation performance, which can avoid incompatibility between the reverse demulsifier and flotation agent during treatment of produced water from offshore oilfields. In our previous work, the effect of the structure of the cationic unit on the reverse demulsification and flotation performance of cationic polyacrylates was studied. However, the structure-activity relationship of cationic polyacrylates has not been systematically studied. In this study, the relationships between the structure (acrylate type, tertiary amine type, mass ratio of acrylate to tertiary amine, and degree of cationicity), interfacial properties (surface tension, interfacial tension, zeta potential, interfacial elastic modulus, interaction force between oil droplets, and film drainage time of an oil-covered bubble), and reverse demulsification and flotation performance of cationic polyacrylates were investigated. A reduction in the elastic modulus of the oil-water interface was the key factor for good reverse demulsification performance, whereas a decrease in the film drainage time of an oil-covered bubble was the key factor for good flotation performance. Ethyl acrylate (EA) was superior to methyl acrylate (MA), and dimethylaminopropyl methacrylamide (DPM) was superior to dimethylaminoethyl methacrylate (DEM). Increases in the mass ratio of ethyl acrylate to dimethylaminopropyl methacrylamide and the degree of cationicity were beneficial for reducing the elastic modulus of the oil-water interface and the film drainage time of an oil-covered bubble. This is the first time that the structure-property-performance relationship of cationic polyacrylates has been systematically studied. A cationic polyacrylate that exhibited both good reverse demulsification performance and good flotation performance is recommended.

Unusual Shell Morphologies of Responsive Amino Core‐Shell Microgels Induced by pH During Shell Synthesis

AbstractThe properties of pH‐responsive microgels are strongly influenced by the pH value during synthesis. In this work, based on a N‐n‐propylacrylamide (NNPAM) core with N‐3‐(dimethylamino)propylmethacrylamide (DAPMA) as a comonomer, a series of core‐shell microgels with shells from NNPAM and N‐(3‐aminopropyl)methacrylamide hydrochloride (APMH) are synthesized at different pH values. While the swelling behavior is studied with temperature‐ and angle‐dependent photon correlation spectroscopy (PCS), the size and morphology are also investigated by means of atomic force microscopy (AFM) and static light scattering (SLS). At acidic pH, rather monodisperse microgels with a very fuzzy shell are obtained. The microgels evolve particulate structures on their shell at intermediate pH until not only a core‐shell microgel but also a secondary microgel species is produced at basic pH. By altering the synthesis pH, it is possible to influence the morphology of core‐shell microgels to suit future applications like the uptake and release of drugs or surface modification.

Development and Characterization of CO2-Responsive Intelligent Polymer Sealant.

In this study, we present an innovative intelligent polymer sealant designed to mitigate CO2 leakage during underground geological storage (CCUS). This sealant is formulated by cross-linking CO2-responsive polymers, specifically acrylamide (AM) and N-[3-(dimethylamino) propyl] methacrylamide (DMAPMA), with polyethylenimine (PEI) serving as the cross-linking agent. The polymer sealant's characteristics were systematically investigated, varying the CO2-responsive polymer content (1.5 wt %) and PEI content (0.1-0.6 wt %). A comprehensive analysis encompassing the rheological properties, thermal behavior, conductivity, and microstructures was conducted. Experimental results indicate that the polymer sealant exhibits excellent injectability, rapid response kinetics, thermal stability, and robust mechanical strength. Upon encountering CO2, the polymer system undergoes a transition from sol to gel state, forming a surface-smooth, uniformly porous three-dimensional (3D) network skeleton structure. Remarkably, the gel's modulus remains relatively unaffected by the shear frequency. Core fluid displacement experiments demonstrated a substantial sealing efficiency of 73.6% for CO2 and an impressive subsequent injection water sealing rate of 96.2%, underscoring its superior sealing and migration performance. In conclusion, the proposed CO2-responsive gel sealant exhibits an exceptional potential for successful utilization in CCUS operations. This advancement introduces a novel avenue to enhance the effectiveness of CO2-responsive gel sealants, thereby contributing to the advancement of CO2 leakage mitigation strategies in geological storage scenarios.

High-performance multifunctional porous iron Acetylacetonate/N, O-doped carbon nanospheres for electromagnetic wave absorption at 2–18 GHz and methyl orange absorption

Nowadays, multifunction is regarded as an advanced development direction of new-generation electromagnetic wave absorption (EMWA) materials to fulfill the ever-growing demands in complex environment and situation. Environmental pollution and electromagnetic pollution are all difficult problems for human beings all the time. Now, there is no multifunctional materials for collaborative treatment of environmental and electromagnetic pollution. Herein, We synthesized nanospheres with divinyl benzene (DVB) and N-[3-(dimethylamino)propyl]methacrylamide (DMAPMA), using a simple one-pot method. After calcination at 800 ℃ in N2, porous N, O-doped porous carbon materials were prepared. By regulating the mole ratio of DVB and DMAPMA, the ratio was 5:1 reached excellent EMWA property. Remarkably, the introduction of iron acetylacetonate into the reaction of DVB and DMAPMA was effective in enhancing the absorption bandwidth to 8.00 GHz at a 3.74 mm thickness, which depended on the synergistic effects from dielectric and magnetic losses. Simultaneously, the Fe-doped carbon materials had a methyl orange adsorption capacity. The adsorption isotherm conformed to the Freundlich model. After methyl orange absorption, the EMWA property did not greatly change. Thus, this research paves the way for the creation of multifunctional materials to solve environmental pollution and electromagnetic pollution together.

Impact of formaldehyde, acetaldehyde, and N-(3-(Dimethylamino)propyl)methacrylamide on the efficacy of the human derived coagulation factor IX

Polymer-borne leachables such as formaldehyde, acetaldehyde, and N-3-(Dimethylamino)propyl)methacrylamide (DMAPMA) may interact with therapeutic proteins. In this study, the leachables were spiked into human derived coagulation factor IX (FIX) at concentrations of 1, 10, 50, 100, and 500 µg/mL, corresponding to a leachable – FIX ratio of 0.5, 5, 25, 50 and 250 %, respectively. The spiked samples were visually inspected, and pH was measured. No visual effects were observed, and pH was within the drug product's specified range. Recovery experiments were performed and no loss of leachables was identified. Protein structure analysis revealed that formaldehyde reacted with lysine contained in two different positions of FIX, in a concentration-dependent manner starting at 10 µg/mL (5 %). The clotting activity of FIX was measured. The activity of the samples spiked with 500 µg/mL (250 %) of formaldehyde dropped by more than half. The activity of the samples spiked with acetaldehyde began to drop at 50 µg/mL (25 %) and continued to decline in concentration-dependent manner. DMAPMA did not impair the activity of FIX. The findings conclude that depending on the concentration, some leachables may react with or modify therapeutic proteins, potentially causing an undesired pharmacological effect however, this is specific to each protein.

Real-time monitoring of CO2 gas using inverse opal photonic gel containing Poly(2-(dimethylamino)ethylmethacrylate

With the rapid progression of global climate changes and air pollution in recent years, there has been growing interest in the sensing and monitoring of CO2 gas. In the present study, an inverse opal photonic gel (IOPG) colorimetric sensor is demonstrated that is capable of real-time monitoring of CO2 gas in an open system without the necessity of a power supply. The IOPGs are fabricated via the opal-templated photo-polymerization of monomer mixtures of hydroxyethyl methacrylate and 2-(dimethylamino)ethyl methacrylate (DMAEMA) or 2-(dimethylamino)propyl methacrylamide (DMAPMAm), followed by template removal. When the IOPG sensor is immersed in water with a steady flow of mixed CO2/N2 gas at various ratios, the CO2 molecules dissolve in the water and are converted to carbonate anions, which subsequently bind to the amino groups of pDMAEMA to build up osmotic pressure, thus leading to swelling of the IOPG. A comparison of the sensing and recovery capabilities of the two types of IOPG indicates that the pDMAEMA-containing IOPG exhibits a limit of detection below 1.2%, and 2.6 times faster CO2 desorption kinetics compared to the pDMAPMAm-containing IOPG. The swelling behavior of the CO2-responsive IOPG is rigorously investigated at various pH values, and temperatures by analyzing the reflectance spectra of the IOPG in the visible wavelength range. The usefulness of the pDMAEMA-IOPG as a real-time CO2 sensor was confirmed by applying it to various carbonated drinks.

CO2 responsive expansion hydrogels with programmable swelling for in-depth CO2 conformance control in porous media

Considerable research efforts have been devoted to finding and developing the oil locked within low-permeability reservoirs. The oil-rock interaction exacerbated in tiny pores and heterogeneities in formation epitomize the challenges accompanying the development of low-permeability reservoirs. CO2 flooding has become a promising treatment to increase displacement efficiency and formation energy for enhanced oil recovery. Nevertheless, due to the mismatch in the viscosity of CO2 with that of the crude oil and the intrinsic heterogeneity of the reservoir, gas channeling is inevitable, resulting in low oil recovery and low CO2 storage efficiency. This paper is motivated to fabricate CO2 intelligent responsive hydrogel that exhibits a delayed swelling: the hydrogel will uptake water and swell when encountering CO2 or H+, to strengthen the plugging capacity for the gas channeling. A two-step method was used to prepare CO2 responsive (CR) hydrogel which has good injection performance and can form gel in-situ to control the gas channeling in low-permeability reservoirs. To achieve the above functions, CR polymer with acrylamide (AM) and N-[3-(Dimethylamino) propyl] methacrylamide (DMAPMA) was synthesized by aqueous free-radical copolymerization. CR hydrogel was prepared by crosslinking CR polymer with polyethyleneimine (PEI). Then 1.2 wt% CR polymer and 0.2 ∼ 0.4 wt% PEI were determined as the optimal synthetic formulation of CR hydrogel which is capable of maintaining stability at 80 ℃ for more than 30 days without dehydration. The gelation time was more than 24 h indicating that the CR hydrogel has good injection and in-depth migration ability. Also, the swelling behaviors of CR hydrogel were studied, and the hydrogel can expand more than 10 times in acidic conditions (pH ∼ 4.5) with respect to about 2 times in neutral conditions (pH ∼ 7). The expansion mechanism is further revealed and proved to be feasible for CO2 channeling control.

Click chemistry tailored benzimidazole functionalized triazole block-co-polymer for emergence of exotic chimaeric nano-crystalsomes

The fabrication of crystalline polymers is synthetically challenging and intellectually stimulating. Amphiphilic block copolymers self-assemble in water to form various vesicle-like architectures depicting curved interfaces, which are shape-translational symmetry incommensurate crystals and ubiquitous. Interestingly, the mechanical properties of the polymeric system improve by forming a crystalline structure. Herein, we for the first time, report the synthesis of a new click monomer (CM), (1-(2-(1H-benzo[d]imidazol-1-yl) ethyl)-1H-1,2,3-triazole-4-yl) methyl methacrylate via azide-alkyne cycloaddition ‘Click reaction’. Furthermore, this monomer was co-polymerized with dimethyl aminopropyl methacrylamide (DMAPMA) via free radical aqueous co-polymerization to generate chimaeric crystalsomes (DPCM) through self-organization of polymeric subunits that structurally resemble classical polymersomes. In an aqueous system, amphiphilic block co-polymers organize within the enclosed membrane to form single crystalline chimaeric substructures. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) have been employed to characterize and understand the nanocrystalline nature of DPCM. The single crystalline nature of these DPCM has been witnessed via X-ray diffraction (XRD) study, consistent with the selected area electron diffraction (SAED) pattern. In addition, the technologically advanced DPCM with nanometer dimensions possesses inherent bioactive properties from click monomeric units, exhibiting remarkable efficacy in conjunction with accelerated wound healing competence in rat model studies.

The effect of molecular structure on the properties of cationic polyacrylate and its flocculation‐flotation performance of oilfield oily wastewater treatment

AbstractWith the increasing amount of oily wastewater produced in the offshore oilfield, more efficient air flotation agent is needed to be developed. Cationic polyacrylate with amphiphilic structure has been found to be a type of potential efficient air flotation agent. However, the effect of molecular structure on its properties and performance was lack of research. In this paper, copolymers with tertiary amine as side group were synthesized by copolymerization of ethyl acrylate (EA) and tertiary amine monomers, and then a series of cationic polyacrylates were prepared by quaternization of tertiary amine with quaternization reagent. The effects of tertiary amine monomer type (including dimethylaminopropyl methacrylamide (DPM) and dimethylaminoethyl methacrylate (DEM)), quaternization reagent type (including 3‐Chloro‐1,2‐Propanediol and 3‐chloro‐2‐hydroxytrimethylammonium chloride) and quaternization degree on the cationic polyacrylate properties and its flotation performance were investigated. The experimental results showed that the flotation performance increased with the increasing hydrophilicity and cation degree of the hydrophilic unit in the cationic polyacrylate. When the tertiary amine monomer was DPM, quaternization reagent was 3‐chloro‐2‐hydroxytrimethylammonium chloride, and theoretical quaternization degree was 100%, the oil removal of product PE‐M‐1.0 was the highest. When PE‐M‐1.0 dosage was 50 mg/L, gas flow was 1 L/min, flotation time was 10 min, its oil removal rate was higher than 95% in the range of 20‑60°C. The results of zeta potential measurement and microfluidic experiment showed that PE‐M‐1.0 can increase the size of oil droplets by destroying the electric double layer on the surface of oil droplets and maintain the stability of bubbles, which was helpful for the improve of gas bubble‐oil droplet collision probability and adhesion efficiency.

Amine-incorporated adsorbents with reversible sites and high amine efficiency for CO2 capture in wet environment

CO2 adsorption in wet environments is attractive but difficult in terms of the unsatisfied adsorption capacity and low efficiency of active sites. Herein, we report the fabrication of a thermal-responsive adsorbent with reversible amine sites by copolymerizing N-acryloyl glycinamide (NAGA), N-[3-(dimethylamino)propyl]methacrylamide (DMAPM), and styrene (ST). During adsorption at 20 °C, the tertiary amines of the DMAPM units stretch out and act as the strong sites in water. The adsorption capacity can reach 98 mL g−1, corresponding to the highest amine efficiency (0.99 mol CO2 per mol amine), which is superior to most reported adsorbents. When elevating temperature for desorption, these active sites are shielded in the adsorbent particles because of the formation of intramolecular hydrogen bonds between the NAGA and DMAPM units. The exquisite utilization of thermal responsiveness endows the adsorbents with reversible amine sites and high amine efficiency, making them promising in practical CO2 capture.

Synthesis of cassava starch-g-acrylic acid/dimethylaminopropyl methacrylamide: A new hydrogel for brine solution

A new hydrogel copolymer was synthesized via the graft copolymerization of acrylic acid (AA) and dimethylaminopropyl methacrylamide (DMAPMA) on cassava starch (CSt) in aqueous solution. FTIR, TGA–FTIR, solid-state 13C NMR, SEM analyses were used to characterize the polymer. The swelling behavior of the polymer was investigated in distilled water and in various brine solutions. The effects of CSt and the ratio of the two monomers on the water absorbency of the polymer was evaluated. CSt improved the polymer swelling properties. Both polyelectrolyte and anti-polyelectrolyte effects occurred and the polymer had good salt-resistance properties in brine solutions. Such polymers have potential applications in the absorption of ultra-high concentration brine solutions.

Highly Sensitive Diffraction Grating of Hydrogels as Sensors for Carbon Dioxide Detection

A diffraction grating of a stimulus-responsive hydrogel was fabricated for the detection of CO2 with a low detection limit. The hydrogel consisted of dimethylaminopropyl methacrylamide (DMAPMA), me...

Synthesis and self-assembly of optically active random copolymers bearing L-alanine and L-glutamic acid moieties in aqueous medium

This study reports the synthesis by free radical polymerization and aggregation behavior of two new optically active hydrophilic random copolymers comprising glutamic acid or alanine-derived acrylamides and N-[3-(dimethylamino)propyl] methacrylamide (DMAPMA) taken in a 3:1 molar ratios. Their structures, chemical composition and optical activity are confirmed by spectral analysis (FTIR, 1H/13C NMR), thermal methods (TGA, DSC), molecular weight measurements (GPC) and specific rotation measurements. In addition, surface tension, fluorescence spectroscopy, dynamic light scattering (DLS), atomic force microscopy (AFM) and transmission electron microscopy (TEM) are utilized for the characterization of the self-assemblies in solution and/or thin films. The critical aggregation concentration (CAC) determined by surface tension and fluorescence spectroscopy shows similar values of 6 × 10−2 and 5 × 10−2 g∙L−1, respectively. Steady-state fluorescence measurements using 1-pyrene-methanol as molecular probe suggest the tendency of micro-domain formation as a result of interpolymer hydrophobic interactions, while their hydrodynamic sizes are determined by DLS technique. Moreover, the micrographs from AFM technique evidence a combination of comb and brush-shaped orderly structures for the L-glutamic acid-based copolymer, and a star-type structure with four arms, in which each arm presents in turn a brush structure for the L-alanine-based copolymer.

Dual Physically Cross‐Linked Hydrogels Incorporating Hydrophobic Interactions with Promising Repairability and Ultrahigh Elongation

AbstractNovel dual physically cross‐linked (DPC) hydrogels with great tensile strength, ultrahigh elongation, and promising repairability are designed by introducing cellulose nanocrystal (CNC) or hydrophobized CNC (CNC‐C8) into polymers physically cross‐linked by hydrophobic forces. C18 alkyl chain is grafted to N‐[3‐(dimethylamino)propyl]methacrylamide (DMAPMA) for hydrophobic monomer (DMAPMA‐C18), and C8 to CNC surface for hydrophobic CNC (CNC‐C8). CNC‐C8 (or CNC) DPC hydrogels are synthesized, with monomers N,N‐dimethylacrylamide (DMAc) and DMAPMA‐C18 polymerized to form the first network physically cross‐linked by hydrophobic interactions, on which the secondary cross‐linking points are formed by hydrophobic interactions between CNC‐C8 and DMAPMA‐C18, electrostatic interactions between CNC‐C8 (or CNC) and DMAPMA, as well as hydrogen bonding between CNC‐C8 (or CNC) and DMAc. Compared with optimum CNC DPC hydrogels of the highest tensile strength (238 ± 8 kPa), the optimum CNC‐C8 DPC hydrogel with 0.0675 w/v% DMAPMA‐C18 and 0.4 w/v% CNC‐C8 possesses stronger tensile strength of 331 ± 32 kPa and excellent elongation of 4268% ± 1446% as well, demonstrating the enhanced mechanical property of the hydrogel by introduced hydrophobic interactions. In addition, such DPC hydrogel can be facilely repaired with tetrahydrofuran (THF) on the cut surfaces while retaining good tensile stress and elongation behaviors.

Study of polymerization kinetics and copolymerization behavior of N‐[3‐(dimethylamino)propyl]methacryamide and cationic surfmers

AbstractGas flotation is one of the important technologies for oily wastewater treatment and the surface‐active polymer is an important kind of developing flotation agents. In this article, the flotation performance, polymerization kinetics, and copolymerization behavior of surface‐active copolymer of N‐[3‐(dimethylamino) propyl] methacrylamide (DMAPMA) and dodecyl dimethyl propenyl ammonium chloride (C12DM) and copolymer of DMAPMA and decyl dimethyl vinylbenzyl ammonium chloride(C10MVBA) were investigated. The flotation experiment showed that both copolymers had an oil removal of 97% at the concentration of 30 mg/L. The result of polymerization kinetics showed that the polymerization initiation rate was influenced by the monomer concentration and the polymerization termination was dominated by bimolecular termination and accompanied by unimolecular termination. The activation energy of DMAPMA‐C12DM copolymerization (89.64 kJ/mol) was smaller than that of DMAPMA‐C10MVBA (91.65 kJ/mol) copolymerization. The reactivity ratios of DMAPMA and C12DM were 0.46 and 15.52, respectively, as well as the reactivity ratios of DMAPMA and C10 MVBA were 1.19 and 35.77, respectively. These results are meaningful for the oily wastewater flotation and the copolymerization mechanism of DMAPMA‐based copolymer.

Microsuspension Polymerization of Styrene Using Cellulose Nanocrystals as Pickering Emulsifiers: On the Evolution of Latex Particles.

We report a mechanistic study of the microsuspension polymerization of styrene stabilized by cellulose nanocrystals (CNCs) in its native form as well as graft-modified with copolymers of styrene and N-3-(dimethylamino)propyl methacrylamide (DMAPMAm) or N,N-(diethylamino)ethyl methacrylate (DEAEMA). Native CNCs and graft-modified CNCs were shown to form stable styrene emulsions with an average droplet diameter of 18-20 and 5-9 μm, respectively. Initiators of widely varying water solubilities [2,2'-azobisisobutyronitrile (AIBN), 2-2'-azobis(2,4-dimethylvaleronitrile) (Vazo-52), and lauroyl peroxide (LPO)] were employed for the polymerizations. The type of initiator and the type of CNC were shown to directly affect the microsuspension polymerization kinetics, particle size, and molecular weight distribution. Using AIBN and Vazo-52, submicron latex particles were observed in the final latex in addition to the desired 3-20 μm CNC-armored microsuspension particles. The resulting latex and microsuspension polystyrene particles were studied for their CNC coverage and surface charge. We found that the presence of CNCs in the aqueous phase did not lead to Pickering emulsion polymerization by heterogeneous nucleation.

Microwave‐Assisted Reversible Addition–Fragmentation Chain Transfer Polymerization of Cationic Monomers in Mixed Aqueous Solvents

AbstractCationic polymers are an interesting class of macromolecules due to their versatility and emerging properties that can be used for various industrial and biomedical purposes. This report is focused on investigating the use of microwave heating in the reversible addition–fragmentation chain transfer polymerization of functional cationic monomers, N‐(3‐aminopropyl)methacrylamide hydrochloride (APMA) and N‐[3‐(dimethylamino)propyl]methacrylamide (DMAPMA). Under comparable polymerization reaction conditions, the microwave‐assisted reaction achieves up to 270% (APMA) and 375% (DMAPMA) rate enhancement over conventional oil‐bath mediated set‐up. Linear relationships are observed between number average molecular weight and monomer conversion for different target degrees of polymerization to give low‐ to high‐molecular‐weight cationic polymers. Chain extension experiments show increase in molecular weight of the cationic polymers with narrow dispersities (Ð < 1.2) indicating retention of the chain transfer agent with no observable aminolysis or hydrolysis during polymerization.

Carbon Dioxide and Nitrogen-Modulated Shape Transformation of Chitosan-Based Composite Nanogels.

Chitosan/poly[N-(3-(dimethylamino)propyl)methacrylamide]/poly(acrylic acid) (CS/PDMAPMA/PAA) composite nanogels (CPACNGs) were fabricated in the solution of chitosan by surfactant-free emulsion polymerization. N-(3-(Dimethylamino)propyl)methacrylamide (DMAPMA) and acrylic acid (AA) were initiated by 2,2′-azobis-2-methyl-propanimidamide to graft from the backbone of chitosan. Nanogels were formed by noncovalent forces, including of hydrogen bonds, hydrophobic, and electrostatic interaction. Nanogels were characterized by transmission electron microscopy, scanning electron microscope dynamic light scattering, X-ray photoelectron spectroscopy, Fourier transform infrared spectrometer spectra, and 1H NMR. Spherical nanoparticles were observed in the latex system. Nanogels exhibited an excellent CO2 responsivity and CO2/N2 reversible response and switchability and had a faster response rate. The morphological shape transformation of nanogels was modulated by bubbling with CO2 and N2. The responsive mechanism was explored by determining the pH and electrical conductivity. In addition, nanogels were successfully emulsified by bubbling with CO2, and then a phase transition was achieved by bubbling with N2 in the organic solvent/water mixture.

Synthesis and Characterization of Amphiphilic Diblock Copolymer by Reverse Iodine Transfer Polymerization (RITP)

Abstract Iodine transfer radical homo- and diblock copolymerization of N-[3-(dimethylamino)propyl] methacrylamide (DMAPMA) with methyl methacrylate (MMA) were carried out in the presence of iodine I2 and 2,2′-azobis(isobutyronitrile) (AIBN) as chain transfer agent and initiator, respectively. Using reverse iodine transfer polymerization (RITP) method based on the in situ generation of transfer agents using molecular iodine I2. The homopolymer and copolymer were characterized by FT-IR and 1H NMR. The self-assembly behaviours of diblock copolymer in water are studied by viscosity and tensiometry techniques. The water-soluble fraction of P(DMAPMA-b-MMA) block copolymer formed micelles which were investigated at 25°C in water at 0.2 mg.mL−1 concentration using a tensiometry device. Dynamic light scattering technique (DLS) was performed over a wide range of concentration to determine hydrodynamic size of the aggregates.