Ethyltrimethylammonium Chloride Research Articles

A Highly Stretchable, Conductive, and Transparent Bioadhesive Hydrogel as a Flexible Sensor for Enhanced Real-Time Human Health Monitoring.

Real-time continuous monitoring of non-cognitive markers is crucial for the early detection and management of chronic conditions. Current diagnostic methods are often invasive and not suitable for at-home monitoring. An elastic, adhesive, and biodegradable hydrogel-based wearable sensor with superior accuracy and durability for monitoring real-time human health is developed. Employing a supramolecular engineering strategy, a pseudo-slide-ring hydrogel is synthesized by combining polyacrylamide (pAAm), β-cyclodextrin (β-CD), and poly 2-(acryloyloxy)ethyltrimethylammonium chloride (AETAc) bio ionic liquid (Bio-IL). This novel approach decouples conflicting mechano-chemical effects arising from different molecular building blocks and provides a balance of mechanical toughness (1.1 × 106 Jm-3), flexibility, conductivity (≈0.29 S m-1), and tissue adhesion (≈27kPa), along with rapid self-healing and remarkable stretchability (≈3000%). Unlike traditional hydrogels, the one-pot synthesis avoids chemical crosslinkers and metallic nanofillers, reducing cytotoxicity. While the pAAm provides mechanical strength, the formation of the pseudo-slide-ring structure ensureshigh stretchability and flexibility. Combining pAAm with β-CD and pAETAc enhances biocompatibility and biodegradability, as confirmed by in vitro and in vivo studies. The hydrogel also offers transparency, passive-cooling, ultraviolet (UV)-shielding, and 3D printability, enhancing its practicality for everyday use. The engineered sensor demonstratesimproved efficiency, stability, and sensitivity in motion/haptic sensing, advancing real-time human healthcare monitoring.

Roughness-Mediated SI-Fe0CRP for Polymer Brush Engineering toward Superior Drag Reduction.

Surface-initiated iron(0)-mediated controlled radical polymerization (SI-Fe0CRP) with low toxicity and excellent biocompatibility is promising for the fabrication of biofunctional polymer coatings. However, the development of Fe(0)-based catalysts remains limited by the lower dissociation activity of the Fe(0) surface in comparison to Cu(0). Here, we found that, by simply polishing the Fe(0) plate surface with sandpaper, the poly(methacryloyloxy)ethyl trimethylammonium chloride brush growth rate has been increased significantly to 3.3 from 0.14 nm min-1 of the pristine Fe(0) plate. The excellent controllability of roughness-mediated SI-Fe0CRP can be demonstrated by customizing multicompartment brushes and triblock brushes. Furthermore, we found that the resulting polymer brush coatings exhibit remarkably low water adhesion (0.097 mN) and an outstanding drag reduction rate of 52% in water. This work provides a promising strategy for regulating the grafting rate of polymer brushes via SI-Fe0CRP for biocompatible marine drag reduction coatings.

Mussel-inspired ionic hydrogel for tactile perception: Toward versatility, robustness and sustainability

The ever-growing wearable and implantable medical devices have spawned an urgent demand for integrating tactile sensors and portable power sources into a single device. However, identifying a suitable material that balances electronic and mechanical performance to simultaneously meet the requirements of high biocompatibility, elasticity, conductivity, and versatility for such soft electronic applications remains a challenge. Here, highly conductive and robust ionic hydrogel is synthesized via a mussel-inspired strategy, where cellulose nanofibers (CNFs) and ZIF-8 particles are introduced into poly(acrylic acid-co-2-(methacryloyloxy)ethyl trimethylammonium chloride) (PADH) matrix for achieving mechanical reinforcement. Besides adhesive strengths of 30.26 kPa, strong hydrogen-bonding central to the embedded CNFs/ZIF-8 joint induces densely cross-linked tough panel points and soft-hard layered network structure that provide tensile strength of 110 kPa, elongation at break up to 697 % (increased by ∼2.2 times and ∼1.9 times, respectively) and compressive strength of 984 kPa. Excellent self-healing (89 % within 12 h) and self-adhesion capabilities (adhesion strength of about 30.26 kPa) are also witnessed, which can be attributed to the reversibility of the abundant hydrogen bonds. Meanwhile, the ion-rich tunnels promoted by the migration of IL/Gly/H2O ternary solvent system (EgHTS) not only significantly enhance the ionic conductivity, but also improve temperature tolerance and provide prolonged resistance to dehydration. The dynamical balance of the electric double layers at the CNF-ZIF-PADH interface leads to highly stable and durable hybrid triboelectric-piezoresistive sensors that are capable identifying both the physical characteristic of dynamic objects and static forces while harvesting mechanical energy, thus enabling versatile, robust, temperature-tolerant conductive hydrogels for self-powered soft electronics.

Functionalization of sterculia gum for making platform hydrogels via network formation for use in drug delivery

Recently, various advancements have been made in the development of functional polymeric materials for innovative applications. Herein this work, functionalization of sterculia gum (SG) was carried out via grafting of poly(2-(methacryloyloxy) ethyltrimethylammonium chloride) (METAC)-polyvinyl pyrrolidone (PVP) to develop hydrogel dressings as a platform for use in drug delivery (DD). The innovation of the present work is the exploration of inherent antioxidant and antimicrobial properties of the SG along with antimicrobial characteristic of poly(METAC) and PVP, to design the doxycycline encapsulated hydrogel dressings for better wound healing. FESEM, EDS and AFM analyzed the surface morphology of hydrogels. FTIR, 13C NMR and XRD inferred inclusion of poly(METAC)-PVP into polymers. 13C NMR confirmed the incorporation of poly(METAC) and PVP onto gum by the presence of a peak at 54.74 ppm because of methyl carbon attached to quaternary nitrogen of poly(METAC) and at 45.48 ppm due to the ring carbon of PVP along with FTIR peak at 949 cm−1 because of CN bending of quaternary nitrogen of poy (METAC). Thermal characterization of copolymers has been performed using TGA analysis. One gram of copolymeric hydrogel dressing absorbed 6.51 ± 0.03 g simulated salivary fluid (SSF) and 7.65 ± 0.03 g simulated wound fluid (SWF). Release of doxycycline drug occurred in a sustained manner and followed the Non-Fickian diffusion mechanism from hydrogels. The release profile was most effectively described by Hixon-Crowell kinetic model. Hydrogel demonstrated biocompatibility and expressed thrombogenicity 79.7 ± 4.9 % during its polymer-blood interactions. Copolymer revealed mucoadhesive property, requiring a force of 77.00 ± 0.01 mN to detach from bio-membrane. Additionally, it exhibited antioxidant features, showing 43.81 ± 0.286 % free radical scavenging. Hydrogel dressings were mechanically stable and revealed 0.76 ± 0.09 N mm−2 tensile strength and 9.18 ± 0.01 N burst strength. Polymer films were permeable to oxygen and water vapor and were impermeable to microorganisms. Hydrogel dressings exhibited antimicrobial properties against Pseudomonas aeruginosa and Staphylococcus aureus bacteria. Overall, these properties displayed the suitability of hydrogels for wound dressing (WD) applications which may actively enhance wound healing.

Adsorption and enrichment of low-concentration heavy metal complexes by retractable claws made of polyelectrolyte brushes

The removal of heavy metal complexes from water at low concentrations poses a difficult challenge as the cost of chemical or energy input is often disproportional to the benefits gained. Herein, we propose a novel strategy by employing polyelectrolyte brushes as the “retractable claws” for adsorption and enrichment of heavy metal complexes. The polyelectrolyte brush constructed by grafting poly[2-(methacryloyloxy)ethyl trimethylammonium chloride] on the reduced graphene oxide (rGO-PMTC), exhibits a high adsorption capacity of 4.80 mg g−1 for 4.96 mg L−1 of Cu-ethylenediaminetetraacetic acid (Cu-EDTA), which is nearly 30 times larger than that of parent graphene oxide. Moreover, a very rapid adsorption rate can be achieved as 7.17 g mg−1 min−1, which is up to 3 orders of magnitude higher than many reported adsorbents. Molecular dynamics simulations reveal that during the adsorption process, the flexible polyelectrolyte brushes are fully extended to form the “claws” for quickly capturing Cu-EDTA complexes by strong electrostatic attraction. Subsequently, the polyelectrolyte brushes shrink with Cu-EDTA-mediated bridging and wrap the heavy metal complexes inside. In addition, the adsorbed Cu-EDTA complexes can be completely released from the polyelectrolyte brushes by simply introducing sodium chloride, resulting in an almost 20-fold enrichment of metal concentration for recycling. After ten adsorption–desorption cycles, the polyelectrolyte brushes only have 10 % reduction in the adsorption efficiency. The novel adsorbent can be extended to the effective removal of other heavy metal complexes with a low concentration and real electroplating wastewater.

Designing aloe vera-sterculia gum based copolymeric hydrogel dressings for drug delivery

Herein the present work, aloe vera (AV) and sterculia gum (SG) based polymer network hydrogels have been designed for use in wound dressing and drug delivery (DD) applications. The hydrogels were prepared by graft copolymerization reaction of poly(2-(methacryloyloxy) ethyl trimethylammonium chloride) [poly (METAC)] onto AV and SG. Polymers were characterized by FESEM, SEM, EDS, AFM, C13 NMR, FTIR, XRD and TGA-DTG analysis. Swelling, drug delivery and biomedical properties of dressings have been evaluated. Sustained diffusion of moxifloxacin drug from dressings exhibited a non-Fickian diffusion mechanism and the release profile was best fitted in the Korsmeyer-Peppas kinetic model. Various interactions of polymers with blood and goat membranes revealed the biocompatible and mucoadhesive nature of the dressings. Hydrogel dressings were found permeable to O2 and water vapour and impermeable to microbes. Overall, these properties revealed that these hydrogels could act as suitable materials for design of wound dressings. Furthermore, antioxidant properties of AV, wound healing characteristic of SG, antibacterial properties of poly(METAC) and encapsulated moxifloxacin drug in hydrogel dressings may enhance the wound healing potential of hydrogel wound dressings (HWD).

The comparison of polymerization activity of typical cationic quaternary ammonium salt monomers

AbstractThe cationic water‐soluble polymers, which are widely used in many areas such as papermaking and separation process, are typically synthesized through polymerization of cationic monomers represented by quaternary ammonium salt. In this work, the polymerization reaction kinetics of three typical quaternary ammonium salt cationic monomers including acryloyl oxygen ethyl trimethyl ammonium chloride (DAC), methyl acryloyl oxygen ethyl trimethyl ammonium chloride (DMC), and methyl acrylamide propyl trimethyl ammonium chloride (MAPTAC) was examined by using the dilatometer method. The results showed that the polymerization rate of all three monomers increased with the increase of initiation temperature, monomer concentration, and initiator concentration. Under the same conditions, the polymerization activity of the three monomers followed the order: DAC > DMC > MAPTAC. The activation energies for the polymerization reaction under the specified conditions were EaDAC = 138.97 kJ/mol, EaDMC = 141.24 kJ/mol, and EaMAPTAC = 226.97 kJ/mol, respectively. The polymerization rate equations were RpDAC = k1[M]4.25[I]0.51, RpDMC = k2[M]3.77[I]0.50, and RpMAPTAC = k3[M]3.30[I]0.49. The polymerization activity of the monomers may be influenced by electronic effects and steric hindrance of the monomer structure. This work has provided a theoretical and experimental foundation for the actual work of structural design and preparation of cationic water‐soluble polymers.

PH-responsive glucose-powered Janus polymer brushes nanomotors for drug delivery and controlled release

Nanostructured drug delivery system (NDDS) has attracted significant attention from the scientific community due to their biocompatibility, stability and modifiability. However, the limited delivery efficiency and low delivery dosages of NDDS have been pressing issues for scientists. In this study, we develop glucose-powered Janus nanomotors (G@JAP@P-ADM) with enhanced diffusion, which is fabricated by formation of glucose oxidase (GOx) and poly[2-(methacryloyloxy)ethyltrimethylammonium chloride] (PMETAC) polymer brushes on opposite surface of gold-platinum (AP) NPs, and adriamycin (ADM) loading on PMETAC chains, and completed efficient drug and high dosages delivery via pH-responsive of the cation polymer brushes and the ADM drug. In glucose solutions, such nanomotors show the self-propulsion motion via cascade reaction and exhibit effective uptake capability to the cancer cells via enhanced diffusion. Fortunately, the cation PMETAC brushes not only enhance diffusion of the nanomotors, but also realize high dose ADM drug delivery via pH-responsive of electrostatic interactions and morphology transformations. Moreover, the ADM also can release itself from polymer chains of nanomotor via charge reversal of pH-responsive. Based on these advantages, the nanomotors increase the ADM drugs dosage at the cancer cell and promote apoptosis. Therefore, such glucose-driven nanomotors exhibit great potential for NDDS and supply novel strategies for enhancing the drug dosage and delivery efficiency.

Preparation and characterization of quaternary bacterial cellulose composites for antimicrobial oil‐absorbing materials

AbstractThe treatment of various types of oily wastewater is paramount for environmental protection. Bacterial cellulose (BC) stands out as a highly promising material for oil/water separation, owing to its exceptional mechanical properties and three‐dimensional porous structures. However, excessive hydroxyl groups on BC make it highly hydrophilic, reducing oil absorption and promoting bacterial growth, affecting its stability. To address these challenges, we developed a straightforward in situ polymerization method for the preparation of BC‐DMC composites. The innovation lies in the concurrent enhancement of BC's hydrophobicity and antimicrobial properties only through the addition of 2‐(Methacryloyloxy)ethyltrimethylammonium chloride (DMC), considerably simplifying the synthesis of materials possessing oil‐absorbing and antimicrobial properties. Morphological and structural characterization results confirmed the successful combination of DMC onto BC while maintaining its porous structure. After process parameter optimization, the BC‐DMC composites exhibited a remarkable increase in contact angle (117.7° compared with pure BC's 19.5°). It also demonstrated excellent oil absorption performance, with maximum capacities exceeding 30 g/g for different oils, maintaining values above 20 g/g even after eight cycles. In addition, the BC‐DMC composites exhibited strong antibacterial activity, with rates of 82.4% against Escherichia coli and 97.5% against Staphylococcus aureus. The antibacterial mechanism of the BC‐DMC composites was also discussed. Our novel BC‐DMC composites provides excellent oil absorption and antibacterial properties, making it highly applicable in the field of oily wastewater treatment and serving as a valuable reference for other researchers.

An Experimental and Computational Evaluation of the Interaction Between Intelligent Ampholyte Acrylamide/Acrylic Acid/2-(Acryloyloxy)ethyl Trimethylammonium Chloride Hydrogel and Dyes

An Experimental and Computational Evaluation of the Interaction Between Intelligent Ampholyte Acrylamide/Acrylic Acid/2-(Acryloyloxy)ethyl Trimethylammonium Chloride Hydrogel and Dyes

Investigation of Adsorption Isotherm Models for Interaction of P(AAm-ClAETA) and Carminic Acid, and Theoretical Approaches

In this study, the adsorption isotherm models for the sorption of carminic acid on P(AAm-ClAETA) hydrogels are explained by experimental and theoretical studies. The crosslinked hydrogels with ethylene glycol dimethacrylate were prepared by radical addition reaction of acrylamide (AAm) and 2-(acryloyloxy)ethyl trimethylammonium chloride (ClAETA) monomers in an aqueous solution. The spectral and morphological analyses of P(AAm-ClAETA) hydrogels were performed by FTIR/ATR and SEM, respectively. The adsorbed amounts of carminic acid on P(AAm-ClAETA) hydrogels were evaluated by Giles, Langmuir, and Freundlich adsorption isotherm models. Langmuir parameters were calculated for the adsorption of the dye on the hydrogels according to the L-type Giles isotherm. In addition, it was determined that its adsorption was appropriate from the RL values calculated for 500 mg L-1 carminic acid concentration. In addition, molecular electrostatic potential (MEP) mapping was performed to predict the reactive sites of P(AAm-ClAETA) hydrogels and carminic acid. The results showed that the theoretical and experimental data of the hydrogels were in agreement with each other. As a result, it can be said that P(AAm-ClAETA) hydrogels are suitable for the removal of anionic dyes such as carminic acid from aqueous solutions.

Fine structural features and proton conduction in zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC): Multinuclear solid-state NMR, impedance and FTIR spectroscopy study

The poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), i.e. one of the most biocompatible synthetic polymer, was synthesized using radical addition-fragmentation chain transfer (RAFT) polymerization and characterized by a wide set of experimental techniques, the 1H, 13C, 15N, 31P NMR, impedance and FTIR spectroscopy among those. The optimized synthesis conditions ensured the high product yield, high purity and narrow molecular weight distribution. The stereochemical content was determined from the complex shaped 13C MAS signal of CH3 group, and the relative content of the adsorbed water - from the 1H MAS spectra. The 1H13C and 1H31P cross-polarization kinetics were measured and processed using the Hirschinger and Raya spin dynamics model. Fine structural details, such as the partial (ca 10%) protonation of the internal PO4− group, the local order and the flexibility of the main chain were deduced. The thermal activation of proton conduction in the wet PMPC was deduced by impedance spectroscopy. The thermal boosting of proton mobility is driven via breaking the cage-like structures of water. This was confirmed by 1H MAS and FTIR spectroscopy. The experimental data for poly[2-(methacryloyloxy)ethyl trimethylammonium chloride] (PMETAC), i.e. cationic proton conducting polymer, which structure is closely related to PMPC, were revisited, compared and discussed.

Enhanced dewaterability of sewage sludge by grafted cationic lignin-based flocculants

Lignin-based flocculants are widely used for wastewater purification, but their application in sludge dewatering has not yet been documented. In this study, a novel cationic lignin-based flocculant named LS-g-CPA was prepared by grafting cationic polyacrylamide (CPA) synthesized from methacryloyloxy ethyltrimethyl ammonium chloride (DMC) and acrylamide (AM) onto sodium lignosulfonate (LS), and its roles and underlying mechanisms in sludge conditioning were investigated. The results showed that LS-g-CPA effectively improved the dewaterability of sludge, reducing the filtration resistance and filter cake moisture content of sludge from 0.61 ± 0.05 × 1012 m/kg to 0.14 ± 0.02 × 1012 m/kg and 85.64 ± 0.25 % to 76.84 ± 0.41 %, respectively. The dewatering performance of LS-g-CPA was positively correlated with the DMC/AM ratio. The quaternary ammonium groups brought by DMC disrupted the reticular structure of extracellular polymeric substances, exposing hydrophobic residues and releasing bound water. Nevertheless, the key to LS-g-CPA for improving sludge dewatering lies more in the amphoteric flocculant properties that enhance sludge flocculation and the octopus-type structure that provides good drainage channels. This study reveals that lignin-based flocculants are effective in improving the dewaterability of sludge, which provides direct evidence for their application in sludge dewatering.

Preparation, characterization and swelling studies of bio-waste-derived absorbent hydrogels

A class of polymeric materials known as “hydrogel products” have a hydrophobic structure that enables them to hold significant volumes of water in their three-dimensional networks. It is thought that it is of utmost importance that they can be used extensively in a variety of industrial, biomedical and environmental applications. In this view, I have synthesized a uniuqe hydrogel made from cellulose extracted from banana pseudostem (BPC). This hydrogel exhibits superabsorbent properties. The synthesis was achieved by free-radical graft copolymerization of poly 2-(acryloyloxy) ethyl trimethylammonium chloride copolymer N,N-dimethylacrylamide (AETAC- co-DMA) onto a BPC backbone using ammonium persulfate as the initiator and methylene bisacrylamide as the cross-linking agent. The graft copolymer was studied using FT-IR spectroscopy to confirm its structure. It was further characterized by field-emission scanning electron microscopy (FESEM) and thermogravimetric analysis (TGA) to determine its morphological and thermal properties, respectively. The Effect of various parameters of free-radical graft copolymerization on the swelling behavior of the hydrogel was studied and the optimized copolymer was used to conduct pH and salt sensitivity tests on the hydrogel. The maximum water uptake of the hydrogel was found to be 427 g/g under optimum conditions of initiator, monomer and cross-linker concentrations of 0.0657 mol/L, 1.6 mol and 0.0972 mol/L correspondingly. The hydrogel was found to be pH and salt-sensitive and the salt uptake followed the order KCl>NaCl>CaCl>FeCl3. The excellent water absorbency, pH and salt responsiveness of the prepared hydrogel suggest its applicability not only in agriculture and wastewater treatment, but also in biomedicine for the controlled release of drugs.

Bioactive surfaces with well-defined amphiphilic copolymers containing a natural terpene-based monomer

New amphiphilic cationic copolymers based on poly((methacryloyloxy) ethyl trimethylammonium chloride) (PMETAC) and bio-based poly(thymol methacrylate) (PTMA) were prepared by atom transfer radical polymerization (ATRP) methods, using low concentration of metal catalyst and a bio-based eutectic mixture (EM), composed of L-menthol and thymol. The antimicrobial activity of the polymers was evaluated against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) bacteria.The results in solution showed that increasing the terpenic segment (PTMA) in the copolymers resulted in lower antimicrobial activity against S. aureus (as the MIC increases from 3.1 to 100 μM) and higher activity against E. coli (as the MIC decreases from 400 to 200 μM).Scanning electron microscopy (SEM) analysis suggests that polymers affected the bacterial viability by damaging the cell structure. The synthesized biocidal polymers were used as additives in polyurethane-based varnish formulations to produce bioactive coated surfaces that were found to be more active against E. coli. Coatings containing either PTMA or PMETAC homopolymers were more efficient than those containing PMETAC-co-PTMA copolymers. A dramatic improvement in the antimicrobial activity of PMETAC-containing varnish against both S. aureus (3 orders of magnitude) and E. coli (4 orders of magnitude) was observed when an aqueous solution of the homopolymer was applied to the dried varnish instead of being incorporated into the varnish formulation. The strategy presented here is simple and opens the door for the preparation of customized bioactive surfaces to prevent bacterial infections.

Amphoteric retarder for long-standing cementing: Preparation, properties and working mechanism

Amphoteric retarder (AIDA) was prepared by radical copolymerization of 2-acrylamido-2-methyl propane sulfonic acid (AMPS), itaconic acid (IA), 2-(Methacryloyloxy) ethyltrimethylammonium chloride (DMC) and methyl allyl polyethenoxy ether (TPEG). The characteristics of AIDA were verified by FTIR and 1HNMR. In addition, the performances of AIDA in cement slurry including thickening time, compressive strength developments, and adaptability to long standing cementing with lager temperature differences were investigated. The results indicated that AIDA possessed excellent temperature-resistance (180 °C) and good adaptability to long standing cementing with larger temperature differences of 90 °C. Finally, the retarding mechanism of AIDA was revealed through transverse relaxation time (T2) distribution, XRD tests, and adsorption behavior of AIDA on cement particles. The results demonstrated that the stronger retarding effect of AIDA originated from the dual adsorption of AIDA on cement particles compared with AMPS-IA copolymer (PAI). AIDA outperformed PAI in its adaptability to long-term cementing, which was responsible to (a): the adsorbed amount of AIDA at higher temperature is higher than that of lower temperatures, therefore, AIDA has a stronger retarding effect at higher temperature and weaker retarding effect at lower temperature. (b) Compared to PAI, the adsorption strength of AIDA is weaker and easy to de-adsorb, so both the retarding effect and the hydration reaction of cement are realized. Thus, the super-retarding phenomenon of cement slurry containing AIDA is effectively prevented.

Oligo (Poly (Ethylene Glycol) Fumarate)-Based Multicomponent Cryogels for Neural Tissue Replacement

Synthetic hydrogels provide a promising platform to produce neural tissue analogs with improved control over structural, physical, and chemical properties. In this study, oligo (poly (ethylene glycol) fumarate) (OPF)-based macroporous cryogels were developed as a potential next-generation alternative to a non-porous OPF hydrogel previously proposed as an advanced biodegradable scaffold for spinal cord repair. A series of OPF cryogel conduits in combination with PEG diacrylate and 2-(methacryloyloxy) ethyl-trimethylammonium chloride (MAETAC) cationic monomers were synthesized and characterized. The contribution of each component to viscoelastic and hydration behaviors and porous structure was identified, and concentration relationships for these properties were revealed. The rheological properties of the materials corresponded to those of neural tissues and scaffolds, according to the reviewed data. A comparative assessment of adhesion, migration, and proliferation of neuronal cells in multicomponent cryogels was carried out to optimize cell-supporting characteristics. The results show that OPF-based cryogels can be used as a tunable synthetic scaffold for neural tissue repair with advantages over their hydrogel counterparts.

PREPARATION AND THERMAL ANALYSIS OF DURIAN PEEL CELLULOSE GRAFTED WITH POLY (2-[ACRYLOYLOXYL]- ETHYL TRIMETHYL AMMONIUM CHLORIDE/CHITOSAN NANOCOMPOSITES AS ANTIMICROBIAL APPLICATION

In this work, facile preparation and low-cost utilizing durian peel organic waste as a cellulose (DPC) source and copolymerization grafted between 2-[acryloyloxyl]-ethyl trimethylammonium chloride (AETAC) and chitosan were developed. Accordingly, a grafting yield of 21.9 % was obtained. In addition, to further understand the characterization of grafted cellulose with AETAC and cellulose grafted with AETAC and chitosan through techniques, including FTIR, SEM, XRD, TGA, and contact angle confirmed the grafting of AETAC and chitosan monomers onto cellulose backbone (DPC-g-AETAC-co-chitosan). The morphology grafting process resulted in the DPC-g-AETAC-co–chitosan with wrinkle structure, coarse surface, and formation of pores, resulting in a crystallinity index slightly reduced from 36.58 to 19.3 %, however, DPC-g-AETAC-co-Chitosan increased in thermal stability. In addition, DPC-g-AETAC-co-chitosan demonstrated excellent antibacterial and antifungal ability against S. aureus, S. epidermis, and C. albicans

Solid-state NMR study of spin dynamics and local disorder in smart polymers: PDMAEMA

The solid-state 1H and 13C NMR spectra as well as the 1H–13C cross-polarization upon magic angle spinning (CP MAS) kinetics were studied for poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA), i.e. a smart pH- and thermo-responsive polymer. The stereochemical content of PDMAEMA was determined from the complex shaped 13C MAS signal of CH3 group. The kinetic data were processed using the Hirschinger and Raya spin dynamics model that includes the complete scheme of rotating frame spin-lattice relaxation pathways. The general solution was adapted for the spin cluster treatment. The earlier studied experimental CP MAS kinetics data of poly [2-(methacryloyloxy)ethyl trimethylammonium chloride] (PMETAC), i.e. one of its quaternized form, were revisited and newly processed applying this model. The spin-lattice relaxation of protons in the rotating frame in PDMAEMA and PMETAC occurs in the same scale from one to tens of milliseconds. Very high anisotropy of spin-diffusion was found for both polymers. However, the local disorder of various spin sites in PDMAEMA is significantly higher than in PMETAC. It is characterized by the order parameters 0.71–0.77 and 0.87–0.91, respectively. The main chain in PDMAEMA is also more disordered and more flexible than in PMETAC.

A Comparative Study of PMETAC-Modified Mesoporous Silica and Titania Thin Films for Molecular Transport Manipulation.

The manipulation and understanding of molecular transport across functionalized nanopores will take us closer to mimicking biological membranes and thus to design high-performance permselective separation systems. In this work, Surface-initiated atom transfer radical polymerization (SI-ATRP) of (2-methacryloyloxy)-ethyltrimethylammonium chloride (METAC) was performed on both mesoporous silica and mesoporous titania thin films. Pores were proven to be filled using ellipsometry and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Furthermore, the employed method leads to a polymer overlayer, whose thickness could be discriminated using a double-layer ellipsometry model. Cyclic voltammetry experiments reveal that the transport of electrochemically active probes is affected by the PMETAC presence, both due to the polymer overlayer and the confined charge of the pore-tethered PMETAC. A more detailed study demonstrates that ion permeability depends on the combined role of the inorganic scaffolds' (titania and silica) surface chemistry and the steric and charge exclusion properties of the polyelectrolyte. Interestingly, highly charged negative walls with positively charged polymers may resemble zwitterionic polymer behavior in confined environments.