Search

A novel but simple design is presented of a multi-ion network with polyamic acid that combines high extensibility and toughness with spontaneous healing ability. Taking advantage of the carboxylate structure of polyamic acid, the introduction of a sufficient number of metal ions to neutralize the carboxylated groups can form reversible ionic bonds within the polymeric network. Dry-solid zinc(II)-poly(amic acid-PDMS) is transparent and exhibits good mechanical properties, including good ultimate strength (~0.267 MPa) and high stretchability (~360%). In addition, this dynamic network can self-heal at ambient temperature without requiring stimulation from heat, a plasticizer, or a solvent. The very simple method of our proposed polyamic acid polymers opens up the possibility of increasingly utilizing high-performance, low-cost, and environmentally friendly polyamic acids instead of polyimides. A simplified multi-ion network is presented, which can toughen and modulate the spontaneous self-healing capability of dry-solid Zn(II)-carboxylate polyamic acid under ambient conditions.

In humans, excessive bleeding during civilian accidents, and surgery account for 40% of the mortality worldwide. Hence, the development of biocompatible hemostatic materials useful for rapid hemorrhage control has become a fundamental research problem in the biomedicine community. In this study, we prepared biocompatible gelatin-tannic acid-κ-carrageenan (GTC) microparticles using a facile Tween 80 stabilized water-in-oil (W/O) emulsion method for rapid hemostasis. The formation of GTC microparticles occurs via polyelectrolyte interactions between gelatin and k-carrageenan as well as hydrogen bonding from tannic acid. In addition, the GTC microparticles formulated in our study showed high water adsorption ability with a low volume-swelling ratio for a particle size of 46 μm. In addition, the GTC microparticles displayed80% biocompatibility in NIH 3T3 cells and5% hemocompatibility in hemolysis ratio tests. Notably, the GTC microparticles induced rapid blood clotting in 50 s and blood loss of approximately 46 mg in the femoral artery of BALB/c female mice with a 100% survival rate that was significantly better than the control group (blood clot time:250 s; blood loss: 259 mg). Thus, the findings from our study collectively suggest that GTC microparticles may play a promising clinical role in medical applications to tackle hemorrhage control.

This study provides a significant contribution to the development of multiple hydrogen-bonded supramolecular nanocarrier systems by demonstrating that controlling the hydrogen bond strength within supramolecular polymers represents a crucial factor to tailor the drug delivery performance and enhance the effectiveness of cancer therapy. Herein, we successfully developed two kinds of poly(ethylene glycol)-based telechelic polymers Cy-PEG and UrCy-PEG having self-constituted double and quadruple hydrogen-bonding cytosine (Cy) and ureido-cytosine (UrCy) end-capped groups, respectively, which directly assemble into spherical nanogels with a number of interesting physical characteristics in aqueous solutions. The UrCy-PEG nanogels containing quadruple hydrogen-bonded UrCy dimers exhibited excellent long-term structural stability in a serum-containing biological medium, whereas the double hydrogen-bonded Cy moieties could not maintain the structural integrity of the Cy-PEG nanogels. More importantly, after the drug encapsulation process, a series of in vitro experiments clearly confirmed that drug-loaded UrCy-PEG nanogels induced selective apoptotic cell death in cancer cells without causing significant cytotoxicity to healthy cells, while drug-loaded Cy-PEG nanogels exerted nonselective cytotoxicity toward both cancer and normal cells, indicating that increasing the strength of hydrogen bonds in nanogels plays a key role in enhancing the selective cellular uptake and cytotoxicity of drugs and the subsequent induction of apoptosis in cancer cells.

Membrane separation has been an efficient and energy saving technique in dealing with greenhouse gases, but the traditional membrane designs might not be able to handle the concomitant environmental pollution due to their fixed properties. Correspondingly, the use of an active-responsive smart membrane appears to be a new trend for membrane development in the coming future, which shows great potential to deal with the obstacles. In this research, we demonstrate a smart graphene-organic framework membrane to enable reversed electrical-switchable permselectivity in CO2 separation. The addition of polydopamine (PDA) to the polyvinylidene fluoride/Graphene (PVDF/G) membranes was done to (i) induce the β-phase of PVDF, since –NH2-functionalized graphene has specific interactions (dipole induced dipole interaction) between graphene-PDA and PVDF; (ii) modify the organic PVDF-inorganic graphene interface; and (iii) facilitate CO2 selective separation. Permeability and permselectivity was increased after applying voltage that resulted in the increase of gas permselectivity in response to the lowest applied voltage range (0–3 V) to the membrane. Digital image correlation method depicted the response of the membrane to voltage and proved that the membrane has high piezoelectric properties that is switchable. Furthermore, PALS studies confirmed the free volume and interlayers in the membrane. This membrane has unique properties because the pore changes from bimodal to single pore distribution.

This work reports a study on employing lignin in the formation of a selective layer of thin-film composite (TFC) membranes for pervaporation desalination. The TFC membranes with lignin-based separation layers are fabricated using a solution-casting method. With a reduction of the separation layer thickness to about 0.47 μm, a water permeation flux of 18.5 kg h−1 m−2 and a salt rejection of above 99.95% have been recorded on the lignin based TFC membrane with a feeding solution of 3.5 wt% NaCl(aq) at 45 °C. The membrane also exhibits high stability in long-term operation tests and can be applied for operations on high salinity water (up to 15 wt% NaCl(aq)). While being applied to seawater desalination, the membrane exhibits a water permeation flux of about 20.4 kg h−1 m−2 and a salt rejection of above 99.95% at 45 °C. A membrane separation process, which uses sustainable materials for salty wastewater treatments and water resource generation, has been demonstrated.

Programmed formation of hierarchical graphene nanosheets, based on a combination of first and second exfoliations using the halogenated solvent ortho-dichlorobenzene (ODCB) and an adenine-functionalized supramolecular polymer (A-PPG), respectively, can be used to directly exfoliate graphite into high-quality graphene nanosheets with wide-range tunable layer thickness. In this study, we discover that natural graphite in ODCB can be directly exfoliated into well-dispersed, dozen-layer exfoliated graphite (EG) nanosheets with relatively weak interlayer interactions; this process is called first exfoliation. On subsequent addition of A-PPG into the EG solution (i.e., second exfoliation), the hydrogen-bonded adenine moieties act as indispensable key units that manipulate the self-assembly behavior of the A-PPG polymers to effectively form long-range ordered lamellar nanostructures on the surface of the graphene nanosheets. This process substantially enhances the long-term dispersion stability of EG in ODCB and achieves the production of exfoliated graphene nanosheets with the desired structural characteristics through simply adjusting the content of A-PPG in the composites. These desirable characteristics of non-covalently functionalized graphene with a supramolecular polymer are extremely rare, but highly attractive for the development of physically custom-tailored graphene based on combined first and second exfoliation processes. Thus, this development provides a facile, highly efficient graphene fabrication process for potential applications in various fields.

Water pollution has become a serious problem in aquatic ecology due to the oil spills and the consistent release of industrial pollutants, such as dyes. Herein, we report a simple method to fabricate superwetting caffeic acid (CA)-polyethyleneimine (PEI)-modified melamine sponges (CA-PEI-MS) for oil-in-water emulsion separation and dye adsorption. The as-fabricated CA-PEI-MS exhibited superhydrophilicity with an approximately zero water contact angel (WCA) and underwater superoleophobicity with an underwater oil contact angel (UWOCA) greater than 150°. The compressed CA-PEI-MS showed an excellent oil-in-water emulsion separation performance with a separation efficiency greater than 97% and a water flux of up to 25,480 L h−1 m−2 bar−1. The recyclability test was used to study the stability of the compressed CA-PEI-MS, after washing with acetone; the flux did not show any significant change during the 12-cycle separation test. The separation efficiency in every cycle was greater than 97%. Due to the availability of rich positive charged amino groups, the as fabricated CA-PEI-MS exhibited adsorption ability towards negatively charged dyes such as, rose bengal (RB) and direct red (DR) with 96% adsorption efficiency. Therefore, the as designed low-cost and eco-friendly preparation of CA-PEI-MS has a great potential for practical application as it shows high separation performances and excellent efficiency.

We report a significant breakthrough in the development of complementary hydrogen-bonded drug-carrier systems, namely the construction of self-assembled nanoparticles with desirable functionalities conferred by the presence of stable complementary uracil–adenine (U–A) hydrogen bonding interactions between the drug and carrier complex. Herein, an adenine-functionalized rhodamine derivative (A-R6G) was successfully synthesized, and exhibited a variety of interesting physical properties including unique hydrophobicity, hydrogen bond-modulated green-fluorescence behavior and potent tumor-cell specific cytotoxicity. A-R6G strongly associates with uracil end-capped difunctional poly(propylene glycol) (BU-PPG) to spontaneously form spherical nanoparticles in aqueous solution due to the complementary U–A interactions between the drug and the carrier. These nanoparticles possess several interesting physical properties, such as ultrahigh drug loading content (up to 84.3%), a wide-range tunable drug loading ratio, high A-R6G-encapsulation stability in serum-rich culture media and pH/temperature-sensitive controlled drug release; these properties are very rare in drug-loaded nanoparticles, but are extremely desirable for drug-delivery applications based on polymeric micelles. Surprisingly, A-R6G-loaded nanoparticles exhibited selective cytotoxicity against cancer cells but had no effects on normal cells, whereas control rhodamine 6G-loaded nanoparticles displayed potent non-selective cytotoxicity, suggesting that the U–A interactions within the nanoparticles critically enhance the tumor-selective cytotoxicity of A-R6G towards cancer cells. Importantly, fluorescence imaging and flow cytometric assays confirmed that A-R6G-loaded nanoparticles were selectively delivered into cancer cells via an endocytic pathway and subsequently induced apoptotic cell death, but had minimal cytotoxic effects on normal cells. Thus, this complementary drug-carrier system has the ability to achieve targeted cancer chemotherapy with high therapeutic efficacy and safety.

Functionalized amphiphilic polymers consisting of hydrophilic poly(ethylene glycol) pendant groups and a hydrophobic poly(epichlorohydrin) backbone can spontaneously self-organize into single-chain...

Water-soluble conjugated polymers (WCPs) composed of a hydrophobic polythiophene main chain with hydrophilic tertiary amine side-chains can directly self-assemble into sphere-like nano-objects in an aqueous solution due to phase separation between the hydrophilic and hydrophobic segments of the polymeric structure. Due to the presence of gas-responsive tertiary amine moieties in the spherical structure, the resulting polymers rapidly and reversibly tune their structural features, surface charge, and fluorescence performance in response to alternating carbon dioxide (CO2) and nitrogen (N2) bubbling, which leads to significantly enhanced fluorescence and surface charge switching properties and a stable cycle of on and off switching response. In vitro studies confirmed that the CO2-treated polymers exhibited extremely low cytotoxicity and enhanced cellular uptake ability in normal and tumor cells, and thus possess significantly improved fluorescence stability, distribution, and endocytic uptake efficiency within cellular organisms compared to the pristine polymer. More importantly, in vivo assays demonstrated that the CO2-treated polymers displayed excellent biocompatibility and high fluorescence enhancement in living zebrafish, whereas the fluorescence intensity and stability of zebrafish incubated with the pristine polymer decreased linearly over time. Thus, these CO2 and N2-responsive WCPs could potentially be applied as multifunctional fluorescent probes for in vivo biological imaging.

Separation technology by using membranes is an effective choice for water treatment, but fouling is a significant problem for membrane applications. Recently, transition-metal dichalcogenide nanosh...

In this study, we fabricated ultrafiltration mixed-matrix membranes through wet phase-inversion method of cellulose acetate (CA) blended with polydopamine (PDA) particles solution. PDA, as an organic and hydrophilic particle, altered the physicochemical and antifouling property of CA membranes. X-ray photoelectron spectroscopy confirmed the presence of PDA particles on the membrane surface. Adding PDA particles led to the formation of macrovoids onto the cross-sectional morphology of CA membranes. This also improved the membrane porosity, pore size, and hydrophilicity. At an optimum concentration of 0.2 wt% PDA, the membrane presented the highest pure water flux of 771.98 L m−2 h−1 at 1 bar and significant oil rejection (93–99%). Furthermore, the modified membrane exhibited better antifouling property (flux recovery = 87%; irreversible fouling = 12%; Reversible fouling = 80%) contrasted to a pristine CA membrane (flux recovery ratio = 70%; irreversible fouling = 25%; reversible fouling = 45%).

Choosing the property of the supporting membrane is crucial in preparing high performing nanofiltration membranes through interfacial polymerization. In this study, an oxygen rich membrane – cellulose triacetate (CTA) – was used to fabricate the support membrane. Polyamide was deposited onto the CTA support using interfacial polymerization of piperazine (PIP) and trimesoyl chloride (TMC). The concentration of the monomers was optimized. Furthermore, the polyamide layer prepared on CTA support exhibited higher separation efficiency for sodium sulfates and dyes compared to using traditional polysulfone (PSf) support. The oxygen groups of CTA facilitate better adsorption of amines on the surface; thus, using low concentration of PIP could still provide a defect-free polyamide layer. Utilizing the optimum condition, the polyamide/CTA membrane delivered a high pure water flux (operating at 6 bar) of 179.5 L/m2h with the following rejections: Na2SO4 = 98.4%; MgSO4 = 60.3%; MgCl2 = 15.0%; NaCl = 3.7%; Rose Bengal = 95.5%; Brilliant Blue R = 99.9%; Amido Black 10B = 90.6%; Orange G = 67.3%. Moreover, the polyamide/CTA membrane had excellent stability at a wide range operating conditions.

Graphene quantum dots(GQDs) were used to possibly cover the structural defects on the graphitic regions of reduced graphene oxide(rGO). The resulting homostructure nanocomposite fillers(rGO + GQD) were incorporated in an alginate solution creating a dense composite membrane for pervaporation. The membranes were applied to separate alcohol/water mixtures in which the successful covering of structural defects was observed with good separation performance of lower molecular weight alcohols. The Raman spectra and elemental analyses confirmed the successful changes on the physical and chemical structures of the homostructured fillers. The X-ray diffraction pattern showed that the crystallinity of the membrane was greatly affected when incorporated with rGO + GQD. The alginate incorporated with 3 wt% of rGO + GQD(Alg-rGO + GQD) has the best pervaporation performance in separating methanol/water mixture with a permeation flux of 2323 g m−2 h−1 and water concentration in permeate of 92.7% at 70 °C. While the positron annihilation lifetime spectroscopy results supported that the minimization of the structural defects enhanced the water selectivity of the membrane by easy transport of water molecules through the free volume spaces and blocks methanol molecules. The results in this study may provide the possible sealing or curing the defects on rGO with GQDs and improve the interfacial interaction with the polymer matrix.

An easy and novel synthetic concept for building intrinsically stretchable and elastic semiconducting polymers is designed in this study, in which a conjugated rod–coil block copolymer with a rigid...

Water-soluble supramolecular polymers can be created by incorporation of self-complementary multiple hydrogen bonding groups. However, technically simple fabrication of water-soluble supramolecular polymers with highly desirable physical properties—to achieve micelles suitable for effective delivery of drugs for cancer treatment—remains a significant challenge. We developed a new polyethylene glycol-based supramolecular polymer containing self-complementary quadruple hydrogen bonding groups, which spontaneously assembles into nanospherical micelles in an aqueous environment. These supramolecular micelles can be readily controlled to obtain the desired structural stability and possess excellent pH-responsive and drug-loading capabilities, as well as good biocompatibility towards both normal and cancer cells. The resulting drug-loaded micelles exhibit tunable drug loading capacity and excellent long-term drug-entrapment stability due to the strong affinity between the drug and micelle core, which led to highly efficient drug loading. In addition, in vitro release assays indicated the drug-loaded micelles can be triggered to rapidly release the drug under mildly acidic conditions. More importantly, fluorescence microscopy and flow cytometry clearly demonstrated that drug-loaded micelles were effectively endocytosed by cancer cells and induced apoptosis; therefore, this newly developed supramolecular system could serve as versatile drug nanovehicle for safe, effective controlled drug release to achieve superior chemotherapeutic effects.

Description, Cascaded microporosity localized on membrane surfaces markedly improved selective transport of small molecules., In membrane-based separation, molecular size differences relative to membrane pore sizes govern mass flux and separation efficiency. In applications requiring complex molecular differentiation, such as in natural gas processing, cascaded pore size distributions in membranes allow different permeate molecules to be separated without a reduction in throughput. Here, we report the decoration of microporous polymer membrane surfaces with molecular fluorine. Molecular fluorine penetrates through the microporous interface and reacts with rigid polymeric backbones, resulting in membrane micropores with multimodal pore size distributions. The fluorine acts as angstrom-scale apertures that can be controlled for molecular transport. We achieved a highly effective gas separation performance in several industrially relevant hollow-fibrous modular platform with stable responses over 1 year.

Bentazone (BEZ) is one of the utmost selective problematic contact-past herbicide with high toxicity for humans owing to feasible contamination of surface and ground water. In this work, an electrochemical sensor has been developed for the sensitive detection of BEZ, based on hierarchically porous three-dimensional (3D) carbon superstructures (CS)–modified electrodes. The CSs (namely, CSHEX, CSPY, CSACN, and CSNOS) were prepared by the pyrolysis process from organic porous polyacrylonitrile (PAN) superstructure particles (namely, PANHEX, PANPY, PANACN, and PANNOS) obtained by free radical polymerization method using different solvents (hexane, pyridine, acetonitrile, and also no solvent). The assembly with the working electrode of CSs causes the electrocatalytic BEZ oxidation by rapid electron transfer compared to the PAN superstructures and bare electrodes. Intriguingly, compared to all electrodes, CSHEX-modified electrode showed the superior electrochemical detection of BEZ at a working potential of 0.99 V (vs. Ag/AgCl), very low detection limit (0.002 μM), wide dynamic linear range (0.03 to 200 μM), high sensitivity (9.95 μA μM−1 cm−2), and excellent reliability. The advanced sensors displayed an intensification of oxidation peak current of BEZ with high selectivity, remarkable sensitivity, and reproducibility for BEZ detection and received satisfactory outcomes designating the application of sensors for the determination of BEZ in river water samples.

In this work, a novel thermoresponsive switching transistor is developed through the rational design of active materials based on the typical field-effect transistor (FET) device configuration, where the active material is composed of a blend of a thermal expansion polymer and a polymeric semiconductor. Herein, polyethylene (PE) is employed as the thermal expansion polymer because of its high volume expansion coefficient near its melting point (90–130 °C), which similarly corresponds to the overheating point that would cause damage or cause fire in the devices. It is revealed that owing to the thermistor property of PE, the FET characteristics of the derived device will be largely decreased at high temperatures (100–120 °C). It is because the high volume expansion of PE at such high temperature (near its Tm) effectively increases the distance of the crystalline domains of poly(3-hexylthiophene-2,5-diyl) to result in a great inhibition of current. Besides, the performance of this device will recover back to its original value after cooling from 120 to 30 °C owing to the volume contraction of PE. The reversible FET characteristics with temperature manifest the good thermal sensitivity of the PE-based device. Our results demonstrate a facile and promising approach for the development of next-generation overheating shutdown switches for electrical circuits.

Among various pore formers, Pluronic F127 (F127), an amphiphilic nonionic surfactant, is an attractive additive which has often been used to create surface pores on hollow fibers and improve the permeate flux. Even though F127 has been employed in polymer dopes for membrane fabrication in various applications, most studies mainly focused on the enhancements of membrane properties instead of its influences on the phase inversion process and membrane formation. Therefore, the objectives of this study were to investigate its effects on the phase inversion process of a polyacrylonitrile/dimethyl sulfoxide/H2O (PAN/DMSO/H2O) system and the formation of PAN hollow fiber membranes. It was found that the addition of F127 reduced the dope stability and facilitated the solvent-nonsolvent demixing, resulting in a faster phase inversion process. In addition, F127 formed micelles in polymer dopes and induced large pores at membrane surface. Moreover, F127 enhanced the N2 permeance and mechanical properties of the resultant hollow fibers. Finally, the PAN/F127 hollow fibers were tested for air filtration and showed excellent filtration performance of >99.999% against NaCl aerosols with a geometric mean size of 43 nm. The hollow fiber spun from the PAN/DMSO dope containing 3 wt% F127 possesses the most balanced filtration performance in terms of filtration efficiency, mechanical properties, and gas permeance. Its filtration performance is also superior to most hollow-fiber air filters in the literature. This study may provide useful insights of using F127 for membrane fabrication for various applications.

The present work is designed to evaluate the feasibility of using polyacrylonitrile (PAN) asymmetric membrane prepared via diffusion induced phase separation (DIPS). The PAN membrane was hydrolyzed using NaOH for different hours to improve its hydrophilicity and tune the microstructure morphology of HPAN1-5h membrane. The PAN and HPAN1-5h membranes were investigated the physicochemical properties by using the ATR-FTIR, water contact angle, Zeta potential and SEM. Besides, the positron annihilation lifetime spectroscopy results reveal that there was a reduction of free volume by increasing hydrolysis time. The breaking of intermolecular hydrogen bonds after desalination prompts a free structure which affects the growth and decline of the dry and wet zones in the membrane. The HPAN1-5h membranes were revealed the hydrolysis time progresses, the surface of the membrane became denser and pore size decreased. It also showed the salt deposition on the surface of the membranes after pervaporation testing. A permeation flux of 48.0 L/m2 h and rejections above 99% was obtained from 3.5 wt% NaCl aqueous feed solution at 60 °C using the HPAN membrane which was hydrolyzed for 1 h (HPAN1h). The HPAN1h membrane gave the highest permeation flux and has stability for up to 80 h of operation.

Injectable thermo-responsive hydrogels have been studied for various biomedical applications including; drug delivery, cell encapsulation, and tissue repairing. There are various natural and synthetic polymers which exhibit homogenous injectable solution at ambient temperature and form a gel in human body temperature. Polysaccharide, polypeptide and other biological macromolecule based hydrogels have been getting immense attention in biomedical application due to their low immunogenicity, abundance in nature, high biocompatibility and biodegradability. This manuscript focuses on polysaccharide and polypeptide based thermo-sensitive hydrogels, and some synthetic polymers which forms in situ gel in response to temperature change from ambient to body temperature. The value of numerous reactive functional groups of biological macromolecular polymers has been discussed for effortless modification and design of bio-macromolecule based thermo-sensitive hydrogels. In addition, we emphasized on the basic mechanisms of the thermo-response processes, the strategies to optimize the desired properties and their applications in local delivery approach.

We propose in this study a facile and versatile strategy for fabricating thin-film nanocomposite (TFN) membranes, wherein polydopamine-piperazine (PDP) nanoparticles were formed in situ from the oxidative polymerization reaction of dopamine and its subsequent reaction with piperazine. Accordingly, PDP nanoparticles were then directly used as nanofillers for TFN membranes fabricated through interfacial polymerization. The characteristics of PDP nanoparticles and the performance of TFN membranes were easily tailored by varying the water-ethanol ratio in the PIP solution, solution pH, dopamine concentration, and reaction time. The TFN-PDP membranes exhibited an optimum separation performance (high water permeability and high salt selectivity): JH2O = 59.1 ± 3.3 L m−2 h−1; RNa2SO4 = 98.0%; RNaCl = 44.1% (6 bar, 25 °C). Moreover, the TFN-PDP membranes demonstrated high water flux recovery and enhanced antifouling property during cycles of filtration tests, with bovine serum albumin protein used as model foulant.

Moderate and eco-pleasing ion-exchange trade membranes are in need to recover acid from industrial waste. Present study is focused on incorporation of plant waste (Azadirachta indica, neem leaves powder (NP)) of different composition as filler to polysulfone (PSf) membrane matrix to achieve acid recovery. Membranes were characterized, their chemical, mechanical and thermal stabilities and effectiveness in acid recovery via diffusion has been inspected. Multi-functional groups (−COOH, -NH2, −OH, -OAc, -C = O) present in different components of NP contributes in their own means in H+ ion transportation through membrane in acid recovery. They assisted formation of hydrogen bond and provided channels for ion permeation, and facilitated selective transportation of H+ ion over Fe2+ ions and explained mechanism is in accordance with Grotthuss-type and vehicle mechanism. Membrane with 15% of NP showed better performance in terms of ion exchange capacity (IEC) and acid recovery, at optimum concentration of NP, composite the membrane showed highest IEC values of 3.9771 mmol/g, UH+ value of ≈46.499 × 10−3 m/h and greater separation factor ≈154, which is higher than commercially available DF-120 membrane. An original thought of utilizing NP in membrane matrix opens up promising opportunities for extremely straightforward, easy, cost-effective and greener methods of recovery acid.

This work reports the utilization of lignin, a renewable and biomass-based material, as an effective modifying agent for thermally stable and hydrophobic membranes based on crosslinked polybenzoxazine (CRPBz) to significantly enhance their permeation fluxes in pervaporation dehydration tests. Lignin could involve in the crosslinking reaction of polybenzoxazine so as to be chemically embedded in the polymer networks. In addition to the inherent hydrophilicity of lignin, lignin could release the hydrophilic groups (phenol and tertiary amine) of crosslinked polybenzoxazine with formation of hydrogen bonding with crosslinked polybenzoxazine, consequently to significantly enhance the hydrophilicity and water permeation fluxes of the studied membranes. With feeding a 70 wt% tetrahydrofuran aqueous solution at 25 °C, lignin modification increases the permeation flux of the CRPBz based membrane from 237 g m−2 h−1 to 490 g m−2 h−1 and separation factor from 11,920 to 19,440. Lignin modification significantly enhances the water permeation flux of the membrane without scarifying separation ability. A 3.4-folds of pervaporation separation index (PSI, the product of permeation flux and separation factor) has been demonstrated with the lignin modification. Similar performance has also been recorded on the tests on a 70 wt% isopropanol aqueous solution. The effect of lignin has been attributed to increase the membrane hydrophilicity for facilitating water permeation. The results demonstrate the wide application scopes of the lignin-modified CRPBz based membranes in pervaporation dehydration based on their high stability and hydrophilicity.

An ultrasensitive light-responsive block copolymer, a combination of a multiarmed poly(ethylene glycol)-b-poly(caprolactone) polymer as a water-soluble element and maleimide-anthracene linkers as a...

Zwitterion augmented forward osmosis (FO) membranes were fabricated having polyamide active layer on the polysulfone support to improve the overall performance and antifouling characteristics. FTIR and XPS were employed in evidencing the incorporation of zwitterion in terms of functional groups and relative compositions of hetero atoms. AFM, SEM, water contact angle and zeta potential measurement are used to characterize the zwitterion augmented surface in terms of surface morphology, surface charge and hydrophilicity/hydrophobicity. Augmentation of zwitterion was found to enhance the hydrophilicity and surface roughness resulting the enhancement in the water permeability. The anionic moiety of the zwitterion was exposed outside, while the cationic moieties of the zwitterion mostly retained towards the core as suggested by negative zeta potential and protein absorption. Incorporation of zwitterion was found to enhance the antifouling property of the membrane as evident from static and dynamic test. The relative composition of zwitterion on active membrane surface was optimized by investigating the tradeoff between water permeability and reverse salt flux.

Graphene oxide quantum dots (GOQDs), a carbon-based nanomaterial resembling the structure of graphene oxide but with a smaller size of

Our present study used 3,3′-diaminobenzidine (DAB) to prepare nanofiltration polyamide membranes. A polyamide layer was formed on a polysulfone (PSf) support through interfacial polymerization; DAB was reacted with different polyacyl chlorides: isophthaloyl chloride, succinyl chloride, and trimesoyl chloride (TMC). Attenuated total reflectance-Fourier transform infrared confirmed the polyamide layer formation. Scanning electron microscopy illustrated that only the reaction between DAB and TMC yielded a defect-free polyamide layer. The membrane preparation conditions comprised the following parameters: DAB and TMC concentrations, immersion time (PSf support in DAB solution), and polymerization reaction time. The optimized membrane delivered an average permeability of 12.5 L m−2 h−1 MPa−1. Its salt rejection followed this order: Na2SO4 (84.2%) > MgSO4 (48.8%) > MgCl2 (14.5%) or NaCl (15.3%). Moreover, the membrane was stable at feed pH of 5–10, at operating temperatures of 25–70 °C, and within a long-term nanofiltration period of 148 h.

Forward osmosis membranes based on ultrathin graphene oxide (GO) were fabricated. Suitable crosslinking agents were used to tune the interlayer spacing of GO sheets to achieve the desired membrane performance. The physicochemical properties of membranes were evaluated using different techniques. The interlayer spacing of GO-based membranes was controlled the interaction between the surface functionality of GO with the nature of crosslinking agents, such as polyvinyl alcohol, meta-phenylenediamine (MPD) and 1,3,5-benzenetricarbonyl chloride (TMC). The covalent bonds between the layer and crosslinking agents effectively suppressed the d-spacing stretching. Unlike other symmetric structures of membranes, the GO-MPD/TMC behaviour observed in the ultrathin polyamide (36 nm) asymmetric structure for the performance of pressure-retarded osmosis (PRO) mode showed the highest flux of 20.8 LMH and low reverse salt flux of 3.4 gMH. A consistent water flux for a long-term PRO operation was achieved using GO-MPD/TMC membrane (∼98.7%). Therefore, the GO-MPD/TMC membrane can be used to suppress internal concentration polarisation.

Self-assembling supramolecular polymer membranes (SPMs), a combination of self-complementary multiple hydrogen bonding interactions and a flexible polymer-based material, can be advantageously used to induce and manipulate the self-assembly of polymer chains in the solid state, making it possible to achieve unprecedented structural and chemical diversity as well as novel functions. Herein, we successfully developed a new ureido-cytosine (UrCy)-functionalized supramolecular polymer [poly(UrCy-PPG)] that exhibits many attractive properties, such as excellent thermoreversible behavior, a unique fiber-like self-assembled microstructure and rapid film-forming ability owing to its reversible UrCy-induced physical cross-linking. In addition, when a poly(UrCy-PPG) film was employed as the filtration membrane in a double-layered filtration system that exhibited a remarkable performance in the filtration of aqueous solutions of the fluorescent dye rhodamine 6G (R6G), the resulting spin-coated R6G films demonstrated increased fluorescence efficiency and improved color stability. Surprisingly, the fluorescence intensity of poly(UrCy-PPG)-filtered films was nearly 6 times higher than that of an unfiltered R6G film and films filtered through the support membrane alone. Given its simplicity, ease of processability, multifunctional features and high filtration efficiency, this newly devised SPM system offers a potential route towards the development of high-performance water-based fluorescent films.

Zwitterionic hydrogels have promising potential as a result of their anti-fouling and biocompatible properties, but they have recently also gained further attention due to their controllable stimuli responses. We successfully synthesized two zwitterionic polymers, poly(2-methacryloyloxyethyl phosphorylcholine) (poly-MPC) and poly(2-(methacryloyloxy)ethyl dimethyl-(3-sulfopropyl)ammonium hydroxide) (poly-DMAPS), which have complementary ionic sequences in their respective zwitterionic side groups and likely form an interpenetrating double network to improve their mechanical strength. The synthesized poly-MPC was blended in a poly-DMAPS matrix (MD gel) and showed high viscosity, while poly-DMAPS was blended in a poly-MPC hydrogel (DM gel) and revealed UCST behavior as the temperature increased. In addition, cross-section images of the MD hydrogel exhibited its compact and uniform structure, while the DM gel was found to exhibit a porous micro-structure with clear boundaries. The results explained the low viscosity of the DM gel, which was also confirmed via 3D Raman mapping. To sum up, the preliminary data demonstrated that binary zwitterionic hydrogels have thermosensitive mechanical properties, promoting further bio-applications in the future, such as in wound healing.

Thin-film composite polyamide (TFC-PA) membranes prepared via interfacial polymerization (IP) are widely reported in water treatment applications, but the inefficient mixing of reactive monomers in the traditional IP process may cause the diffusion-limited growth of PA layer and the incomplete IP reaction, resulting in limited control over the morphology and microstructure of PA layer, and thus the membrane performance. Various strategies to address above issues have been explored via different chemical modifications. In this work, a "green" ultrasound-assisted interfacial polymerization approach is employed for the first time to fabricate TFC membranes for forward osmosis and nanofiltration applications. Ultrasound in IP process enlarges the mixing area of reactive monomers, facilitates the mass transport of the amine monomer, therefore contributing to an efficient monomer mixing and the resultant higher IP reaction degree. Additionally, the disrupted PA chain packing, more penetrated amine monomers and generated nanovoids contribute to a relative loose PA layer. Effects of ultrasound power on the microstructure (crosslinking degree and free volume) and morphology (roughness and thickness) of the resultant TFC membranes are also investigated systematically. In comparison with the control membrane, TFC membranes formed via ultrasound-assisted IP exhibit much superior separation performance.

Simple fabrication and manipulation of multi-stimuli responsive supramolecular polymers based on multiple, self-complementary, hydrogen bond interactions with the desired self-assembly behavior and desirable micellar properties for effective drug delivery under physiological conditions remains a grand challenge. Herein, we successfully developed a dual light- and temperature-responsive uracil-based polymer, BU-PPG, that spontaneously self‐assembles to form micelle-shaped nanoparticles in phosphate-buffered saline (PBS) via supramolecular interactions between uracil moieties. The resulting micelles exhibited controlled light-sensitive photodimerization, a low critical micellization concentration, low cytotoxicity towards MCF-7 cells and tunable drug-loading capacity, as well as extremely high drug-entrapment stability in media containing serum. These features make BU-PPG micelles highly attractive as a potential candidate for safe, effective delivery of anticancer drugs. Importantly, when irradiated with UV light at 254 nm, the drug-loaded irradiated BU-PPG micelles could be easily tuned to obtain the desired phase transition temperature, remained highly stable under normal physiological conditions for prolonged periods of time, and rapidly released the encapsulated drug when the temperature was increased to 40 °C due to an efficient temperature-induced hydrophilic-hydrophobic phase transition. Collectively, these advantages suggest the newly developed BU-PPG supramolecular system may represent a promising new strategy towards the development of controlled release drug delivery systems.

Fucoidan is an abundant marine sulfated polysaccharide extracted from the cell wall of brown macroalgae (seaweed). Recently, fucoidan has been highly involved in various industrial applications, such as pharmaceuticals, biomedicals, cosmetics, and food. However, the presence of a sulfate group (negative surface charge) in the fucoidan structure limits its potential and biological activity for use in biomedical applications during cellular uptake. Thus, we aimed to improve the uptake of fucoidan by using an L-arginine uptake enhancer within an in vitro study. A Fucoidan–L-Arginine (Fuc-L-Arg) fiber complex was prepared via α-helical electrostatic interactions using a freeze-drying technique and confirmed using field-emission scanning electron microscopy, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. In addition, fucoidan was conjugated with cyanine 3 (Cy3) dye to track its cellular uptake. Furthermore, the results of Fuc-L-Arg (1:1, 1:2.5) complexes revealed biocompatibility &gt, 80% at various concentrations (5, 10, 25, 50, 100 µg/mL). Owing to the higher internalization of the Fuc-L-Arg (1:5) complex, it exhibited &lt, 80% biocompatibility at higher concentrations (25, 50, 100 µg/mL) of the complex. In addition, improved cellular internalization of Fuc-L-Arg complexes (1:5) in HeLa cells have been proved via flow cytometry quantitative analysis. Hence, we highlight that the Fuc-L-Arg (1:5) fiber complex can act as an excellent biocomplex to exhibit potential bioactivities, such as targeting cancers, as fucoidan shows higher permeability in HeLa cells.

Enzymatic detachment of cells might damage important features of cells and could affect subsequent function of cells in various applications. Therefore, non-enzymatic cell detachment using thermosensitive polymer matrix is necessary for maintaining cell quality after harvesting. In this study, we synthesized thermosensitive PNIPAm-co-AAc-b-PS and PNIPAm-co-AAm-b-PS copolymers and LCST was tuned near to body temperature. Then, polymer solutions (5% w/v, 10% w/v, and 20% w/v) were spin coated to prepare films for cell adhesion and thermal-induced cell detachment. The apha-step analysis and SEM image of the films suggested that the thickness of the films depends on the molecular weight and concentration which ranged from 206 nm to 1330 nm for PNIPAm-co-AAc-b-PS and 97.5 nm to 497 nm for PNIPAm-co-AAm-b-PS. The contact angles of the films verified that the polymer surface was moderately hydrophilic at 37°C. From cell attachment and detachment studies, RAW264.7 cells, were convincingly proliferated on the films to a confluent of >80 % within 48 days. However, relatively more cells were grown on PNIPAm-co-AAm-b-PS (5%w/v) films and thermal-induced cell detachment was more abundant in this formulation. As a result, commercial cytodex 3 microcarrier was coated with PNIPAm-co-AAm-b-PS (5%w/v) and interestingly enhanced cell detachment with preserved potential of recovery was observed at low temperature during 3D culturing. Thus, surface modification of microcarriers with PNIPAm-co-AAm-b-PS could be vital strategy for non-enzymatic cell dissociation and able to achieve adequate number of cells with maximum cell viability, and functionality for various cell-based applications. Keywords: surface coated microcarriers; thermosensitive polymer; non-enzymatic cell detachment

Integrating anticancer drugs and diagnostic agents in a polymer nanosystem is an emerging and promising strategy for improving cancer treatment. However, the development of multifunctional nanoparticles (NPs) for an "all-in-one" platform characterized by specific targeting, therapeutic efficiency, and imaging feedback remains an unmet clinical need. In this study, pH-responsive mixed-lanthanide-based multifunctional NPs were fabricated based on simple metal-ligand interactions for simultaneous cancer cell imaging and drug delivery. We investigated two new systems of alginate-polydopamine complexed with either terbium/europium or dysprosium/erbium oxide NPs (Tb/Eu@AlgPDA or Dy/Er@AlgPDA NPs). Tb/Eu@AlgPDA NPs were then functionalized with the tumor-targeting ligand folic acid (FA) and loaded with the anticancer drug doxorubicin (DOX) to form FA-Tb/Eu@AlgPDA-DOX NPs. Using such systems, the mussel-inspired property of PDA was introduced to improve tumor targetability and penetration, in addition to active targeting (via FA-folate receptor interactions). Determining the photoluminescence efficiency showed that the Tb/Eu@AlgPDA system was superior to the Dy/Er@AlgPDA system, presenting intense and sharp emission peaks on the fluorescence spectra. In addition, compared to Dy/Er@AlgPDA NPs (82.4%), Tb/Eu@AlgPDA NPs exhibited negligible cytotoxicity with93.3% HeLa cell viability found in MTT assays at NP concentrations of up to 0.50 mg/mL and high biocompatibility when incubated with zebrafish (

pH-Responsive hydrogen-bonded supramolecular micelles, composed of a water-soluble poly(ethylene glycol) polymer with two terminal sextuple hydrogen bonding groups, can spontaneously organize in aqueous media to give well-defined, uniformly sized spherical micelles. The supramolecular micelles exhibit a number of unique physical characteristics, such as interesting amphiphilic behavior, desirable micellar size and nanospherical morphology, excellent biocompatibility, tailorable drug-loading capacities, and high structural stability in media containing serum or red blood cells. In addition, the drug release kinetics of drug-loaded micelles can be easily manipulated to achieve the desired release profile by regulating the environmental pH, thus these micelles are highly attractive candidates as an intelligent drug carrier system for cancer therapy. Cytotoxicity assays showed that the drug-loaded micelles induced pH-dependent intracellular drug release and exerted strong antiproliferative and cytotoxic activities toward cancer cells. Importantly, cellular uptake and flow cytometric analyses confirmed that a mildly acidic intracellular environment significantly increased cellular internalization of the drug-loaded micelles and subsequent drug release in the cytoplasm and nucleus of cancer cells, resulting in more effective induction of apoptotic cell death. Thus, this system may provide an efficient route toward achieving the fundamental properties and practical realization of pH-sensitive drug-delivery systems for chemotherapy.

Two-dimensional (2D) MoS2core-shell nanoparticles were synthesized using an eco-friendly surface functionalization-agent with L-glutathione and cystamine (L-GSH–MoS2–CYS) using ultrasonic frequency of 20–25 kHz. The novel modified electrode was evaluated for the electrochemical detection of doxorubicin (DOX), through cyclic and differential pulse voltammetric techniques. The electro-catalytic oxidation currents of DOX exhibited a linear relationship in the concentration ranges 0.1–78.3 and 98.3–1218 μM, with a detection limit of 31 nM. A sensitivity of 0.017μA μM−1 cm−2 was acquired at 0.48 V. The fabricated L-GSH–MoS2–CYS modified electrode showed excellent precision, selectivity, repeatability, and reproducibility during the determination of DOX levels in blood serum samples. Thus, the fabricated L-GSH–MoS2–CYS/GCE modified electrode has potential for clinical applications for optimization of chemotherapeutic drugs owing to its selectivity, ease of preparation, and long-term stability.

Development of stimuli-responsive supramolecular micelles that enable high levels of well-controlled drug release in cancer cells remains a grand challenge. Here, we encapsulated the antitumor drug doxorubicin (DOX) and pro-photosensitizer 5-aminolevulinic acid (5-ALA) within adenine-functionalized supramolecular micelles (A-PPG), in order to achieve effective drug delivery combined with photo-chemotherapy. The resulting DOX/5-ALA-loaded micelles exhibited excellent light and pH-responsive behavior in aqueous solution and high drug-entrapment stability in serum-rich media. A short duration (1&ndash, 2 min) of laser irradiation with visible light induced the dissociation of the DOX/5-ALA complexes within the micelles, which disrupted micellular stability and resulted in rapid, immediate release of the physically entrapped drug from the micelles. In addition, in vitro assays of cellular reactive oxygen species generation and cellular internalization confirmed the drug-loaded micelles exhibited significantly enhanced cellular uptake after visible light irradiation, and that the light-triggered disassembly of micellar structures rapidly increased the production of reactive oxygen species within the cells. Importantly, flow cytometric analysis demonstrated that laser irradiation of cancer cells incubated with DOX/5-ALA-loaded A-PPG micelles effectively induced apoptotic cell death via endocytosis. Thus, this newly developed supramolecular system may offer a potential route towards improving the efficacy of synergistic chemotherapeutic approaches for cancer.

In this study, we prepared ferulic acid (FA) and paclitaxel (PTX) co-loaded polyamidoamine (PAMAM) dendrimers conjugated with arginyl-glycyl-aspartic acid (RGD) to overcome P-glycoprotein (P-gp)-mediated multidrug resistance (MDR). FA was released in greater extent (80%) from the outer layer of the dendrimers compared with PTX (70%) from the interior of the dendrimers. FA improved intracellular availability of PTX via P-gp modulation in drug-resistant cells. In vitro drug uptake data show higher PTX delivery with RGD-PAMAM-FP than with PAMAM-FP in drug resistant KB CH-R 8-5 cell lines. This indicates that RGD facilitates intracellular PTX accumulation through active targeting in multidrug-resistant KB CH-R 8-5 cells. The terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick-end labeling assay data and membrane potential analysis in mitochondria confirm the enhanced anticancer potential of RGD-PAMAM-FP nanoaggregates in drug-resistant cells. We also confirmed by the increased protein levels of proapoptotic factors such as caspase 3, caspase 9, p53, and Bax after treatment with RGD-PAMAM-FP nanoaggregates and also downregulates antiapoptotic factors. Hence, FA-PTX co-loaded, RGD-functionalized PAMAM G4.5 dendrimers may be considered as an effective therapeutic strategy to induce apoptosis in P-gp-overexpressing, multidrug-resistant cells.

Physically cross-linked supramolecular polymers composed of a hydrophobic poly(epichlorohydrin) backbone with hydrogen-bonding cytosine pendant groups and hydrophilic poly(ethylene glycol) (PEG) side chains spontaneously self-assemble to form highly controlled, reversible supramolecular polymer networks (SPNs) because of cytosine-induced transient cross-linking. Owing to their simple synthesis procedure and ease of tuning the cytosine and PEG contents to obtain varying degrees of SPNs within the polymer matrix, the resulting polymers exhibit a unique surface morphology, wide-range tunable mechanical/rheological properties, and surface wettability behavior as well as high biocompatibility and structural stability in normal cell- and red blood cell-rich media. Cell culture experiments and fluorescent images clearly demonstrated that the incorporation of cytosine and PEG units into the SPN-based polymer substrates efficiently promoted cellular attachment and accelerated cell growth. Importantly, scratch wound-healing assays revealed that the cytosine-functionalized substrates promoted rapid cell spreading and migration into the damaged cellular surface and accelerated the wound-healing rate. These results indicate that the presence of cytosine units within polymer substrates is crucial for the construction of multifunctional tissue engineering scaffolds with tailorable physical characteristics in order to promote cell adhesion, proliferation, and differentiation.

In this study, polydopamine (PDA) particles were embedded into polyethersulfone (PES) membrane through wet-phase separation. We considered two concentration of PES solution—17 and 19 wt%. Adding different concentration of PDA (0–0.7 wt%) into the two solutions revealed an opposite effect on the characteristic and performance of the membrane. Incorporating PDA particles in 17 wt% PES solution was resulted in a decreased in pure water flux, and increased in dye rejection; Whereas, incorporating PDA particles in 19 wt% PES solution boosted the pure water flux with keep dye rejection of ~99.0%. At the optimum concentration of 0.5 wt% PDA added to 19 wt% PES solution, the following dye rejections were obtained: RMethylene Blue = 99.90 ± 1.45%; RProcion Blue H-5R = 98.33 ± 0.57%; RDirect Red 23 = 99.90 ± 1.82%; RBrilliant Blue = 99.90 ± 0.94%; RRose Bengal = 99.90 ± 0.0%; RDirect Red 80 = 99.12 ± 0.41%; for the salt rejections: (RNaCl = 10.59 ± 5.23%; RNa2SO4 = 8.87 ± 4.99%; RMgCl2 = 10.45 ± 6.85%; RMgSO4 = 10.02 ± 3.87%). This shows that the selectivity of the fabricated membrane towards different dyes and common inorganic salts is high. PDA is a favorable option for fabricating membranes for dye desalination under appropriate PES concentration.

Superhydrophilic zwitterions on the membrane surface have been widely exploited to improve antifouling properties. However, the problematic formation of a &lt, 20 nm zwitterionic layer on the hydrophilic surface remains a challenge in wastewater treatment. In this work, we focused on the energy consumption and time control of polymerization and improved the strong hydrophilicity of the modified polyvinylidene difluoride (PVDF) membrane. The sulfobetaine methacrylate (SBMA) monomer was treated with UV-light through polymerization on the PVDF membrane at a variable time interval of 30 to 300 s to grow a poly-SBMA (PSBMA) chain and improve the membrane hydrophilicity. We examined the physiochemical properties of as-prepared PVDF and PVDF&ndash, PSBMAx using numeric analytical tools. Then, the zwitterionic polymer with controlled performance was grafted onto the SBMA through UV-light treatment to improve its antifouling properties. The PVDF&ndash, PSBMA120s modified membrane exhibited a greater flux rate and indicated bovine serum albumin (BSA) rejection performance. PVDF&ndash, PSBMA120s and unmodified PVDF membranes were examined for their antifouling performance using up to three cycles dynamic test using BSA as foulant. The PVDF-modified PSBMA polymer improved the antifouling properties in this experiment. Overall, the resulting membrane demonstrated an enhancement in the hydrophilicity and permeability of the membrane and simultaneously augmented its antifouling properties.

Biotin receptors are overexpressed by various types of solid cancer cells and play a significant role in tumor metabolism, growth, and metastasis. Thus, targeting the biotin receptors on tumor cells may enhance the efficiency and reduce the side-effects of chemotherapy. The aim of this study was to develop a biotin-coupled poly(amido)amine (PAMAM) (PG4.5) dendrimer nanoparticle to enhance the tumor-specific delivery and intracellular uptake of anticancer drugs via receptor-mediated endocytosis. We modified PG4.5 with diethylenetriamine (DETA) followed by biotin via an amide bond and characterized the resulting PG4.5-DETA-biotin nanoparticles by 1H NMR, FTIR, and Raman spectroscopy. Loading and releasing of gemcitabine (GEM) from PG4.5-DETA-biotin were evaluated by UV&ndash, Visible spectrophotometry. Cell viability and cellular uptake were examined by MTT assay and flow cytometry to assess the biocompatibility, cellular internalization efficiency and antiproliferative activity of PG4.5-DETA-biotin/GEM. Gemcitabine-loaded PG4.5-DETA-biotin nanoparticles were spherical with a particle size of 81.6 &plusmn, 6.08 nm and zeta potential of 0.47 &plusmn, 1.25 mV. Maximum drug-loading content and encapsulation efficiency were 10.84 &plusmn, 0.16% and 47.01 &plusmn, 0.71%, respectively. Nearly 60.54 &plusmn, 1.99% and 73.96 &plusmn, 1.14% of gemcitabine was released from PG4.5-DETA-biotin/GEM nanoparticles after 48 h at the acidic pH values of 6.5 and 5, respectively. Flow cytometry and fluorescence microscopy of cellular uptake results revealed PG4.5-DETA-biotin/GEM nanoparticles selectively targeted cancer cells in vitro. Cytotoxicity assays demonstrated gemcitabine-loaded PG4.5-DETA-biotin significantly reduced cell viability and induced apoptosis in HeLa cells. Thus, biotin-coupled PG4.5-DETA nanocarrier could provide an effective, targeted drug delivery system and selectively convey gemcitabine into tumor cells.

In this study, the basal spacing of montmorillonite (MMT) was modified through ion exchange. Two kinds of MMT were used: sodium-modified MMT (Na-MMT) and organo-modified MMT (O-MMT). These two particles were incorporated separately into the thin-film nanocomposite polyamide membrane through the interfacial polymerization of piperazine and trimesoyl chloride in n-hexane. The membrane with O-MMT (TFNO-MMT) has a more hydrophilic surface compared to that of membrane with Na-MMT (TFNNa-MMT). When various types of MMT were dispersed in the n-hexane solution with trimesoyl chloride (TMC), O-MMT was well-dispersed than Na-MMT. The poor dispersion of Na-MMT in n-hexane led to the aggregation of Na-MMT on the surface of TFNNa-MMT. TFNO-MMT displayed a uniform distribution of O-MMT on the surface, because O-MMT was well-dispersed in n-hexane. In comparison with the pristine and TFNNa-MMT membranes, TFNO-MMT delivered the highest pure water flux of 53.15 &plusmn, 3.30 L∙m&minus, 2∙h&minus, 1 at 6 bar, while its salt rejection for divalent ions remained at 95%&ndash, 99%. Furthermore, it had stable performance in wide operating condition, and it exhibited a magnificent antifouling property. Therefore, a suitable type of MMT could lead to high separation efficiency.

Electroactive polypyrrole-molybdenum disulfide (MoP) nanocomposites were synthesized and used for modifying screen-printed carbon electrodes (SPCEs) for ultrasensitive detection of berberine, an anticancer drug, in rat plasma. The electroactive nanocomposites were fabricated by exfoliating MoS2 followed by pyrrole polymerization. The effect of polypyrrole in the MoP nanocomposite was evaluated by varying the pyrrole concentration during polymerization, and the resulting nanocomposites prepared with pyrrole concentrations of 10, 20, 30 μL were named as MoP-1, MoP-2, and MoP-3, respectively. The electrochemical characterization of the three MoP nanocomposite sensors revealed that MoP-2/SPCE exhibited the highest electroactivity. The detection of berberine by the three MoP-coated SPCEs revealed that MoP-2/SPCE exhibited the highest activity against berberine due to a two-electron transfer mechanism on the MoP-2/SPCE electrode surface. The detection limit of berberine using the MoP-2/SPCE sensor was found to be about 0.05 μM, which is remarkably lower than the reported detection limits. The interference study proved the selectivity of the MoP-2/SPCE sensor toward berberine in the presence of other bioactive molecules and metal ions. The designed MoP-2/SPCE sensor retained 92% of its initial activity after 15 days of storage at room temperature, with RSD values of about 2.95% and 3.68% for the repeatability and reproducibility studies. Finally, the detection limit of berberine in a rat plasma sample determined using the MoP-2/SPCE sensor was found to be about 5 μM.

The ability to tune the surface properties of a polymer film in a simple and effective manner is important for diverse biological, industrial, and environmental applications. In this work, we investigated whether or not the surface free energy of poly(vinyl phenol, PVPh) can be tuned by adjusting the casting solvent and the thermal treatment time, which alters the proportions of intra-and intermolecular hydrogen bonding interactions. Compared to the untreated sample, in tetrahydrofuran (THF) system, the thermal treatment resulted in a lower proportion of intermolecular hydrogen bonds and a concomitant decrease in the surface free energy (from 39.3 to 18.8 mJ/m2). In contrast, the thermal treatment in propylene glycol methyl ether acetate (PGMEA) and ethyl-3-ethoxypropionate (EEP) systems increased the proportion of intermolecular hydrogen bonds and the surface free energy of the polymer thin films, from 45.0 to 54.3 mJ/m2 for PGMEA and from 45.5 to 52.9 mJ/m2 for EEP. Controlling intermolecular hydrogen-bonding interactions is a unique and easy method for tuning the surface free energies of polymer substances.