Diethylene Glycol Dimethacrylate Research Articles

Real‐time dielectric monitoring of isothermal polymerization of methyl cyanoacetate and diethylene glycol dimethacrylate

AbstractDielectric spectroscopy (DS) was employed to monitor the isothermal polymerization processes of P(MCA‐DEGDMA) formed by the alternating copolymerization of methyl cyanoacetate (MCA) and diethylene glycol dimethacrylate (DEGDMA) at different temperatures in real time. P(MCA‐DEGDMA) is a polyether containing functional groups (O, CN, COOCH3) which can promote the transport of ions Li+, thereby having the potential to apply in polymer electrolytes. It is beneficial to investigate the effect of temperature and time on P(MCA‐DEGDMA) polymerization and choose a suitable synthesis strategy through dielectric monitoring. A time‐ and temperature‐dependent relaxation process induced by orientational polarization of the P(MCA‐DEGDMA) chain was observed over a frequency range from 10 kHz to 4 × 106 Hz. The time to reach polymerization equilibrium (tequ) and the dielectric conversion were determined through the time variations of the conductivity at low frequency (κl). The polymerization process shows the characteristic of “fast followed by slow,” and the tequ can be advanced by raising the polymerization temperature. In addition, by discussing the monitoring time dependence of relaxation time (τ) and permittivity (ε), it was concluded that the extent of polymerization (α) for P(MCA‐DEGDMA) at 40°C is the largest, and the optimal polymerization temperature is between 30 and 50°C. Furthermore, the free activation energy (ΔG), activation enthalpy (ΔH), and activation entropy (ΔS) of the relaxation process caused by the motion of the P(MCA‐DEGDMA) chain in three temperature ranges (10–20°C, 30–40°C, 50–60°C) were calculated by using Eyring's equation, from which the physical image of various structures and conformations of the P(MCA‐DEGDMA) chain during monitoring was proposed. Considering the effect of temperature on the generation and migration of free ions, and on the structure and conformation of the P(MCA‐DEGDMA) chain, some suggestions for the synthesis of P(MCA‐DEGDMA) are given: during the polymerization, the temperature is controlled at 10°C in the early stage and then gradually raised to 40°C, which may be beneficial to improving the extent of polymerization of P(MCA‐DEGDMA). Our work may be helpful to investigate the polymerization process of polyether obeying the same synthesis mechanism with P(MCA‐DEGDMA). It can be proven that DS is useful in detecting the inner information of the system changing over time through our work.

Confinement of Rh nanoparticles in triphenylphosphine oxide-functionalized core-crosslinked micelles for aqueous biphasic hydrogenation catalysis

The introduction of phosphine oxide as anchoring groups in the hydrophobic core of amphiphilic star-block copolymers leads to greatly improved confinement of rhodium nanoparticles (RhNPs) inside the nanoreactors with a benefit in aqueous biphasic catalysis. The copolymers are specially designed core-crosslinked micelles (CCMs) forming a stable latex by reversible addition-fragmentation chain-transfer (RAFT) polymerization. They possess a hydrophilic shell made of polycationic 4-vinyl-N-methylpyridinium iodide P(4VPMe+I−) chains, a triphenylphosphine oxide (TPPO)-functionalized polystyrene core and are crosslinked at the inner end of the polystyrene chains by diethylene glycol dimethacrylate (DEGDMA) (TPPO@CCM-C). Ex-situ synthesized RhNPs readily cross the hydrophilic shell and remain anchored within the CCM nanoreactor cores. The RhNP-loaded TPPO@CCM-C latex was applied as catalyst in the hydrogenation of styrene under mild conditions with complete selectivity towards ethylbenzene and average turnover frequency (TOF) up to 12000 h−1, corresponding to a corrected TOF (cTOF) up to 16800 h−1 based on only surface atoms of the RhNPs. Moreover, the catalytic phase proved recyclable after product extraction with diethyl ether, demonstrating efficient retention of the RhNPs by the core TPPO ligands. Although the activity decreased after the first catalytic run, it converged to a stable average TOF of ca. ∼1025 h−1 (cTOF of ca. ∼1440 h−1), which was similar to that of an extensively pre-washed RhNP-TPPO@CCM-C latex. This phenomenon is attributed to a promoter effect of adsorbed ligands, which were used as stabilizer for the RhNPs synthesis and were gradually removed during the work-up washings between recycles.

Urethane dimethacrylate-based photopolymerizable resins for stereolithography 3D printing: A physicochemical characterisation and biocompatibility evaluation

Vat photopolymerisation (VP) three-dimensional printing (3DP) has attracted great attention in many different fields, such as electronics, pharmaceuticals, biomedical devices and tissue engineering. Due to the low availability of biocompatible photocurable resins, its application in the healthcare sector is still limited. In this work, we formulate photocurable resins based on urethane dimethacrylate (UDMA) combined with three different difunctional methacrylic diluents named ethylene glycol dimethacrylate (EGDMA), di(ethylene glycol) dimethacrylate (DEGDMA) or tri(ethylene glycol) dimethacrylate (TEGDMA). The resins were tested for viscosity, thermal behaviour and printability. After printing, the 3D printed specimens were measured with a digital calliper in order to investigate their accuracy to the digital model and tested with FT-IR, TGA and DSC. Their mechanical properties, contact angle, water sorption and biocompatibility were also evaluated. The photopolymerizable formulations investigated in this work achieved promising properties so as to be suitable for tissue engineering and other biomedical applications.Graphical abstract

Graphite nanopowder incorporated xanthan gum scaffold for effective bone tissue regeneration purposes with improved biomineralization

In the current work, biomaterial composed of Xanthan gum and Diethylene glycol dimethacrylate with impregnation of graphite nanopowder filler in their matrices was fabricated successfully for their potential usage in the engineering of bone defects. Various physicochemical properties associated with the biomaterial were characterized using FTIR, XRD, TGA, SEM etc. The biomaterial rheological studies imparted the better notable properties associated with the inclusion of graphite nanopowder. The biomaterial synthesized exhibited a controlled drug release. Adhesion and proliferation of different secondary cell lines do not generate ROS on the current biomaterial and thus show its biocompatibility and non-toxic nature. The synthesized biomaterial's osteogenic potential on SaOS-2 cells was supported by increased ALP activity, enhanced differentiation and biomineralization under osteoinductive circumstances. The current biomaterial demonstrates that in addition to the drug-delivery applications, it can also be a cost-effective substrate for cellular activities and has all the necessary properties to be considered as a promising alternative material suitable for repairing and restoring bone tissues. We propose that this biomaterial may have commercial importance in the biomedical field.

Acrylic modified kraft lignin microspheres as novel support for immobilization of laccase from M. thermophila expressed in A. oryzae (Novozym® 51003) and application in degradation of anthraquinone textile dyes

The novel lignin-based microspheres (LMS-DEGDMA) were produced through a two-step modification procedure consisting of kraft lignin (KL) modification with acrylic acid synthesized from fructose; and suspension and copolymerization of acrylic acid modified KL (KL-A) with diethylene glycol dimethacrylate (DEGDMA). The applied procedure provided LMS-DEGDMA microspheres in the size range of 50–90 µm with specific surface area of 39 m2/g, porosity εp 62, pore diameters of 4–20 nm and total pore volume of 0.14 cm3/g. Immobilization of laccase from Myceliophthora thermophilia expressed in Aspergillus oryzae (Novozyme® 51003) on LMS-DEGDMA was explored. By optimization of the immobilization process, it was demonstrated that laccase immobilization on LMS-DEGDMA exhibited the best results (protein immobilization yield of 70 %, activity yield of 27 %, and catalytic activity of 262 IU/g of support) when the immobilization was carried out at pH 5.0 and 100 mg of offered protein per g support during 1 h. Additionally, the LMS-DEGDMA-laccase preparation showed efficiency (>80 %, 5–7 cycles) in decolorization of anthraquinone dyes (Lanaset® violet B, Lanaset® blue 2 R and C.I. Acid Green 40) and their mixture. In case of Lanaset® violet B, LMS-DEGDMA improved laccase's kinetics characteristics (90 % over 24 h) along with operational stability (> 63 % catalytic activity, 7 cycles).

Dimethylaminoethyl Methacrylate/Diethylene Glycol Dimethacrylate Grafted onto Folate-Esterified Bagasse Xylan/Andrographolide Composite Nanoderivative: Synthesis, Molecular Docking and Biological Activity.

As a biocompatible biomaterial, bagasse xylan (BX) has been widely used in the biomedical field. The low biological activity of andrographolide (AD) restricts its development, so AD with certain anticancer activity is introduced. We use chemical modification methods such as grafting and esterification to improve the biological activity and make a novel anticancer nanomaterial. On the basis of the esterification of a mixture of BX and AD with folic acid (FA), a novel anticancer nanoderivative of bagasse xylan/andrographolide folate-g-dimethylaminoethyl methacrylate (DMAEMA)/diethylene glycol dimethacrylate (DEGDMA) nanoparticles (FA-BX/AD-g-DMAEMA/DEGDMA NPs) was synthesized by introducing DMAEMA and DEGDMA monomers through a graft copolymerization and nanoprecipitation method. The effects of reaction temperature, reaction time, the initiator concentration and the mass ratio of FA-BX/AD to mixed monomers on the grafting rate (GR) were investigated. The structure of the obtained product was characterized by FTIR, SEM, XRD and DTG. Further, molecular docking and MTT assays were performed to understand the possible docking sites with the target proteins and the anticancer activity of the product. The results showed that the GR of the obtained product was 79% under the conditions of the initiator concentration 55 mmol/L, m (FA-BX/AD):m (mixed monomer) = 1:2, reaction temperature 50 °C and reaction time 5 h. The inhibition rate of FA-BX/AD-g-DMAEMA/DEGDMA NPs on human lung cancer cells (NCI-H460) can reach 39.77 ± 5.62%, which is about 7.6 times higher than that of BX. Therefore, this material may have potential applications in the development of anticancer drug or carriers and functional materials.

Nanogold-capped poly(DEGDMA) microparticles as surface-enhanced Raman scattering substrates for DNA detection

A novel platform for surface-enhanced Raman scattering (SERS) was fabricated consisting of diethylene glycol dimethacrylate microparticles prepared by gamma-radiation initiated polymerization and decorated with gold nanoparticles. The comparison of bare and decorated microparticles shows significant SERS enhancement in the Raman signal of rhodamine 6G on the latter. For 532, 633 and 785 nm excitations the near-infrared one was found to show the highest enhancement on the substrate, which also showed excellent temporal stability and spatial uniformity. The practical application potential of the SERS substrate is demonstrated with the detection of deoxyribonucleic acid sequences.

Core-crosslinked micelles with a poly-anionic poly(styrene sulfonate)-based outer shell made by RAFT polymerization

Core-crosslinked micelles (CCMs) with a permanently charged anionic shell of sodium poly(styrene sulfonate) (PSS–Na+) chains have been developed by a convergent three-step one-pot RAFT polymerization starting with 4-cyano-4-thiothiopropylsulfanyl pentanoic acid (CTPPA, R0-SC(S)SnPr) as chain transfer agent, which includes polymerization-induced self-assembly (PISA) in the second step. The final crosslinking step of the R0-(SS-Na+)x-b-Sty-SC(S)SnPr diblock chains was carried out with diethylene glycol dimethacrylate (DEGDMA), either diluted into styrene (DEGDMA/St = 10:90) or neat. The morphology of the intermediate micelles and of the final CCM particles was studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM) as a function of the relative degrees of polymerizations for the shell, core, and crosslinking blocks. Conformational instability was observed for the aqueous dispersions of the diblock micelles, especially with the shorter PSt blocks, yielding equilibria with single chains and large agglomerates. However, crosslinking led to well-defined CCMs with narrow size distributions for the optimized polymer compositions. The DLS analysis in a compatibilizing 60:40 THF/H2O solvent mixture demonstrates that the final step of the polymer synthesis has quantitatively crosslinked all diblock arms.

Direct and indirect eluates from bulk fill resin-based-composites

ObjectivesTo compare elutable substances directly released from bulk-fill (BF) resin-based composites (RBCs) with indirect elution from teeth restored with a BF composite. In addition to (co)monomers, the analytical focus was on other potentially toxic ingredients or impurities. Furthermore, the barrier function of the residual dentin/adhesive layer was studied. MethodsSix BF-RBC materials were studied. For each material subgroup, ten human third molar teeth with standard Class-I occlusal cavities were prepared and provided with a three-step adhesive system and the respective composite restoration (tooth groups). Same sized control specimens of the restorative material were prepared (‘direct BF-RBC’ groups). Each specimen was placed in an elution chamber such that the elution media (ethanol/water, 3:1) only contacted the tooth root or ¾ height of each specimen. They were incubated at 37 °C for up to 7 d. Samples of eluate were taken after 1, 2, 4 and 7 d and were analysed by high-temperature gas chromatography/mass spectrometry. Results(Co)monomers such as Bisphenol A ethoxylate dimethacrylate (bisEMA) or tetraethylene glycol dimethacrylate (TEEGDMA) were mostly found in the eluates of the ‘direct BF-RBC’ groups in statistically significantly greater amounts than in the eluates of the ‘tooth groups’. The residual dentin and/or adhesive layers acted as a diffusion barrier for most of the substances except for triethylene glycol dimethacrylate (TEGDMA) or diethylene glycol dimethacrylate (DEGDMA). For TEGDMA up to 3 orders of magnitude more were found in the ‘tooth groups’ compared to the ‘direct BF-RBC’ groups, evidently released by the adhesive system.Substances of Very High Concern (SVHC) including TINUVIN® 328 and BPA were found mainly in the eluates of ‘direct BF-RBC’ groups. SignificanceFor estimation of biocompatibility, a total system, specifically BF-RBC + adhesive, should always be investigated since individual considerations, such as only elution from a BF-RBC, do not correctly reflect the total clinical situation. The focus of elution tests should not only be on the co(monomers), but also on other ingredients or impurities that may be released.

Raman spectroscopic study of gamma radiation‐initiated polymerization of diethylene glycol dimethacrylate in different solvents

AbstractIn this work, the degree of conversion and polymerization kinetics of diethylene glycol dimethacrylate (DEGDMA) monomer in different solvents upon gamma irradiation with different doses have been studied by Raman spectroscopy and mass difference measurements. Density functional theory calculations were performed on the monomer and the crosslinked structure to obtain the assignment of Raman peaks to specific bonds. The evolution of the bonding configuration of the structure with dose and the composition of the monomer mixture was investigated. The dependence of the polymerization rate on the solvent type was explained by the mechanism of the polymerization affected by the relative solubility of the components of the monomer mixture. Raman measurements revealed also that there are not fully crosslinked monomer molecules in the polymer matrix.

ВЛИЯНИЕ СШИВАЮЩЕГО АГЕНТА НА ЭЛЕКТРОХИМИЧЕСКОЕ И КОНФОРМАЦИОННОЕ ПОВЕДЕНИЕ ПОЛИМЕРОВ С МОЛЕКУЛЯРНЫМИ ОТПЕЧАТКАМИ НА ОСНОВЕ МЕТАКРИЛОВОЙ КИСЛОТЫ И 4-ВИНИЛПИРИДИНА В ВОДНОЙ СРЕДЕ

Molecularly imprinted polymers (MIPs) based on methacrylic acid (MAA) and 4-vinylpyridine (4VP) of two types have been synthesized (the difference in types is based on the use of ethylene glycol dimethacrylate (EGDMA) and diethylene glycol dimethacrylate (DEGDMA) as a crosslinking agent). Salts of cerium, praseodymium, neodymium, samarium, and europium were used as templates for the synthesis. Control samples of Molecularly imprinted polymers were also synthesized (samples synthesized in exactly the same way, but without the templates).Electrochemical and conformational behavior of the synthesized structures in an aqueous medium was studied. Molecularly imprinted polymers are weakly exposed to swelling and ionization due to tight crosslinking, while it should be noted that a high degree of crosslinking leads to high mechanical strength of macromolecular structures.Comparison of the measured parameters (electrical conductivity, pH) of molecularly imprinted polymers containing a template with control samples of MIP indicate the presence of cavities complementary to the template (rare-earth metal ion) used in their synthesis. In the presence of MIP synthesized in the presence of EGDMA (MIP-1) higher values of electrical conductivity and pH are observed as compared to MIP synthesized in the presence of DEGDMA (MIP-2) due to less tight crosslinking.

Experimental dentin adhesives containing calcium orthophosphate particles: Effect on dentin bond strength, micro-permeability and collagen degradation

PurposeTo assess the effect of dicalcium phosphate dihydrate (DCPD) or mineral trioxide aggregate (MTA) particles on the microtensile bond strength (μTBS), micro-permeability and enzymatic activity at the adhesive-dentin interface of experimental dental adhesives. Materials and methodsAn experimental ethanol-based, two-step etch-and-rinse adhesive system was prepared. Four experimental groups were tested, based on the type of particle added: (1) DCPD functionalized with diethylene glycol dimethacrylate (DCPD_DEGDMA), (2) citric acid (DCPD_CA), (3) calcium silicate (MTA) and (4) unfilled (control). All particles were added at 10 wt%. Human third molars had their occlusal enamel removed and dentin surface polished. After acid etching, the adhesives were applied on the dentin surfaces and the teeth were restored with a commercial nanofilled resin composite. The μTBS and micro-permeability were tested after 24 h or 2 months of storage in simulated body fluid (SBF) at 37 °C. Bonded interfaces were observed using scanning electron microcopy (SEM). Gelatinolytic activity at the adhesive interfaces was assessed by in situ zymography at 24 h and 2 months in SBF/37 °C. The results were described as relative florescent units (RFU). μTBS data were analyzed by ANOVA/Games–Howell test. Data from micro-permeability and in situ zymography were analyzed by Kruskal–Wallis/Mann–Whitney test (alpha: 5%). ResultsDifferences in μTBS were found among adhesives (control = MTA > DCPD_CA > DCPD_DEGDMA, p < 0.001), but not between storage times. The control group showed the lowest permeability at both observation periods. Except for DCPD_CA, no significant increases in micro-permeability were observed after 2 months. All groups presented significant reductions in RFU values between 24 h and 2 months. DCPD_DEGDMA (at 24 h) and MTA (at 2 months) presented statistically lower RFU than the control (p < 0.01). ConclusionEvidence of reduced MMP activity was observed at adhesive interfaces with the use of experimental adhesives containing calcium-releasing particles. However, after two months, bond strength and micro-permeability results suggest that interfacial stability was not affected by adhesive formulation.

Triphenylphosphine-Functionalized Core-Cross-Linked Micelles and Nanogels with a Polycationic Outer Shell: Synthesis and Application in Rhodium-Catalyzed Biphasic Hydrogenations.

Unimolecular amphiphilic nanoreactors with a poly(4-vinyl-N-methylpyridinium iodide) (P4VPMe+ I- ) polycationic outer shell and two different architectures (core-cross-linked micelles, CCM, and nanogels, NG), with narrow size distributions around 130-150 nm in diameter, were synthesized by RAFT polymerization from an R0 -4VPMe+ I- 140 -b-S50 -SC(S)SPr macroRAFT agent by either chain extension with a long (300 monomer units) hydrophobic polystyrene-based block followed by cross-linking with diethylene glycol dimethacrylate (DEGDMA) for the CCM particles, or by simultaneous chain extension and cross-linking for the NG particles. A core-anchored triphenylphosphine (TPP) ligand functionality was introduced by using 4-diphenylphosphinostyrene (DPPS) as a comonomer (5-20 % mol mol-1 ) in the chain extension (for CCM) or chain extension/cross-linking (for NG) step. The products were directly obtained as stable colloidal dispersions in water (latexes). After loading with [RhCl(COD)]2 to yield [RhCl(COD)(TPP@CCM)] or [RhCl(COD)(TPP@NG)], respectively, the polymers were used as polymeric nanoreactors in Rh-catalyzed aqueous biphasic hydrogenation of the model substrates styrene and 1-octene, either neat (for styrene) or in an organic solvent (toluene or 1-nonanol). All hydrogenations were rapid (TOF up to 300 h-1 ) at 25 °C and 20 bar of H2 pressure, the biphasic mixture rapidly decanted at the end of the reaction (<2 min), the Rh loss was negligible (<0.1 ppm in the recovered organic phase), and the catalyst phase could be recycled 10 times without significant loss of catalytic activity.

Influence of the Structure of a Surface Layer of Methyl Methacrylate-Based Cationic Particles on Adsorption of Biomolecules

Crosslinked cationic particles 200–600 nm in diameter have been synthesized via emulsifier-free copolymerization of methyl methacrylate and 2-aminoethyl methacrylate hydrochloride in the presence of cross-linking agents (N,N'-methylenebisacrylamide, triethylene glycol dimethacrylate, and diethylene glycol dimethacrylate). It has been shown that polymer particles with a maximum concentration of surface functional groups (1.42 µmol/m2) and a stable structure of a surface layer are formed only in the presence of ethanol (20 vol %). The synthesized particles efficiently adsorb biologically active substances, and their dispersions are stable against aggregation in buffer solutions at pH 7.0.

Characterization of luminescent monodisperse microparticles prepared by gamma radiation-initiated polymerization

Abstract Fluorescent microparticles have been prepared by gamma radiation-initiated precipitation polymerization of diethylene glycol dimethacrylate monomer with ethyl propionate solvent and fluorescein isothiocyanate isomer-I (FITC) fluorophore. Different FITC concentrations and irradiation conditions were used, and their effect on the particle properties was studied. The samples were characterized by scanning electron microscopy, Raman and photoluminescence spectroscopies. Our results showed that the size of the microspheres is dependent on the composition of the monomer mixture. The uniformity of the microparticles decreases with increasing FITC concentration, relative to the monomer. Changes in the emission spectrum of the FITC were also observed after irradiation. The gamma irradiation-initiated polymerization was found to be a promising and simple technique to prepare luminescent spherical microparticles.

Development of Neutral pH-Responsive Microgels by Tuning Cross-Linking Conditions.

Polymer microgels that respond in a range of neutral pH can be useful for the development of molecular imaging tools and drug-delivery carriers. Here, we describe a simple approach in developing microgels that undergo volume phase transitions and substantial nuclear magnetic resonance (NMR) relaxometric changes within a narrow pH range of 6.4 to 7.4. The pH-responsive microgels were synthesized using methacrylic acid and a series of ethylene glycol dimethacrylate cross-linkers with repeating units of ethylene glycol that range from one to four. NMR relaxometry demonstrated that the transverse relaxation time (T2) of a suspension containing microgels that were cross-linked with diethylene glycol dimethacrylate sharply decreases at the pH where volume phase transition occurs. The polymer microgels cross-linked with 40 and 45 mol% of diethylene glycol dimethacrylate caused about 50% T2 reduction with decreasing pH from 6.8 to 6.4. These results demonstrated that responses of microgels to a range of neutral pH can be easily tuned by using appropriate cross-linkers with certain cross-linking degree. This approach can be useful in developing highly sensitive molecular sensors for magnetic resonance imaging (MRI) of tissue pH values.

Synthesis of Nixantphos Core-Functionalized Amphiphilic Nanoreactors and Application to Rhodium-Catalyzed Aqueous Biphasic 1-Octene Hydroformylation.

A latex of amphiphilic star polymer particles, functionalized in the hydrophobic core with nixantphos and containing P(MAA-co-PEOMA) linear chains in the hydrophilic shell (nixantphos-functionalized core-crosslinked micelles, or nixantphos@CCM), has been prepared in a one-pot three-step convergent synthesis using reversible addition-fragmentation chain transfer (RAFT) polymerization in water. The synthesis involves polymerization-induced self-assembly (PISA) in the second step and chain crosslinking with di(ethylene glycol) dimethacrylate (DEGDMA) in the final step. The core consists of a functionalized polystyrene, obtained by incorporation of a new nixantphos-functionalized styrene monomer (nixantphos-styrene), which is limited to 1 mol%. The nixantphos-styrene monomer was synthesized in one step by nucleophilic substitution of the chloride of 4-chloromethylstyrene by deprotonated nixantphos in DMF at 60 °C, without interference of either phosphine attack or self-induced styrene polymerization. The polymer particles, after loading with the [Rh(acac)(CO)2] precatalyst to yield Rh-nixantphos@CCM, function as catalytic nanoreactors under aqueous biphasic conditions for the hydroformylation of 1-octene to yield n-nonanal selectively, with no significant amounts of the branched product 2-methyl-octanal.

Development of a Thermoresponsive Polymeric Composite Film Using Cross-Linked β-Cyclodextrin Embedded with Carbon Quantum Dots as a Transdermal Drug Carrier.

Polymeric nanocomposite films are used as promising transdermal drug carriers because of the improved patient compliance, easy application on skin, and noninvasiveness. A thermoresponsive polymeric composite film has been developed here through the deposition of carbon quantum dots (CQDs) on functionalized β-cyclodextrin (β-CD). The composite has been developed by grafting of poly(N-vinyl caprolactam) on β-CD, followed by cross-linking of diethylene glycol dimethacrylate and subsequent deposition of CQDs. CQDs have been prepared from waste pomegranate peels via a hydrothermal method. To enlighten the thermoresponsive nature of the composite film, lower critical solution temperature, as well as temperature-dependent swelling behavior, has been studied. The composite demonstrates excellent rheological features. The developed polymeric composite film is nontoxic toward NIH 3T3 fibroblast cell lines. On the deposition of CQDs on the copolymer, the penetration power and fluorescent property have been improved, which help to track the cells in vitro. This film is worthy to be applied to the skin. It can efficiently load lidocaine hydrochloride monohydrate (LHM). In vitro and ex vivo skin permeation profiles reveal the sustained release behavior of loaded LHM at average skin temperature and pH.

Core-Cross-Linked Micelles Made by RAFT Polymerization with a Polycationic Outer Shell Based on Poly(1-methyl-4-vinylpyridinium)

A convergent synthesis of amphiphilic polymers with a polystyrene (PS) core and a polyelectrolytic poly(1-methyl-4-vinylpyridinium iodide) (P4VPMe+I–) shell is reported. The polymers were obtained by reversible addition–fragmentation chain transfer (RAFT) polymerization in water using a trithiocarbonate chain transfer agent [R0-SC(S)SPr, R0 = −C(Me)(CN)CH2CH2COOH]. Two types of particle structure, both having a spherical morphology and diameters in the 85–150 nm range, have been obtained as stable latexes with polymer content up to 10% in weight. The first structure consists of core-cross-linked micelles (CCMs), where amphiphilic P4VPMe+I–-b-PS arms are cross-linked at the hydrophobic end by the use of diethylene glycol dimethacrylate. The Coulombic repulsion between the outer shells of the precursor micelles ensures the absence of macrogelation during the cross-linking step. The second structure consists of nanogels (NGs), where the entire hydrophobic core is cross-linked during the last step of simultaneous chain extension and cross-linking of a P4VPMe+I–-b-PS intermediate with a short PS block. The lack of radical polymerization for the 4VPMe+I– monomer and the lack of chain extension with styrene for a R0-P4VPMe+I–-SC(S)SPr intermediate were circumvented by the synthesis of R0-P4VP-b-PS-SC(S)SPr containing a short PS block by sequential RAFT polymerization of 4-vinylpyridine (4VP) and styrene, followed by quantitative cationization of the P4VP block by MeI and subsequent sequential (for the CCMs) or simultaneous (for the NGs) chain extension and cross-linking.

Synthesis of Glutamic Acid Derived Organogels and their Applications in Dye Removal from Aqueous Medium

AbstractTo develop glutamic acid derived cross‐linked polymeric organogels for dye adsorption from aqueous media, dimethyl 2‐(methacrylamido)pentanedioate (Glu‐MAC) is polymerized using diethylene glycol dimethacrylate as cross‐linker via the reversible addition‐fragmentation chain transfer (RAFT) technique to synthesize cross‐linked polymeric organogels with pendant glutamate moieties. The mechanical properties of organogels are examined by rheological study. The organogels exhibit higher value of storage modulus (G′) than the loss modulus (G′′) within the linearity limits of deformation, and strong dependence of G′ values on the extent of cross‐linking in the gel matrix. Field emission scanning electron microscopy shows porous structure of the gel matrix, therefore, organogels are able to exhibit swelling behaviors in organic solvents such as dichloromethane, N,N‐dimethylformamide, tetrahydrofuran, acetone, and methanol. Dye adsorption properties of these organogels are investigated using different aqueous dye solutions, such as crystal violet (CV), malachite green (MG), rhodamine‐B, and uranine. The gels show high dye adsorption capacities (≥97%) toward cationic dyes like CV and MG.