scholarly journals Wrinkling on Stimuli-Responsive Functional Polymer Surfaces as a Promising Strategy for the Preparation of Effective Antibacterial/Antibiofouling Surfaces

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4262
Author(s):  
Carmen M. González-Henríquez ◽  
Fernando E. Rodríguez-Umanzor ◽  
Matías N. Alegría-Gómez ◽  
Claudio A. Terraza-Inostroza ◽  
Enrique Martínez-Campos ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Acrylic Acid ◽  
Antibacterial Properties ◽  
Chemical Properties ◽  
Stimuli Responsive ◽  
Release Capacity ◽  
Carboxylic Groups ◽  
Wrinkled Surface ◽  
Surface Patterns ◽  
Adsorption Desorption

Biocompatible smart interfaces play a crucial role in biomedical or tissue engineering applications, where their ability to actively change their conformation or physico-chemical properties permits finely tuning their surface attributes. Polyelectrolytes, such as acrylic acid, are a particular type of smart polymers that present pH responsiveness. This work aims to fabricate stable hydrogel films with reversible pH responsiveness that could spontaneously form wrinkled surface patterns. For this purpose, the photosensitive reaction mixtures were deposited via spin-coating over functionalized glasses. Following vacuum, UV, or either plasma treatments, it is possible to spontaneously form wrinkles, which could increase cell adherence. The pH responsiveness of the material was evaluated, observing an abrupt variation in the film thickness as a function of the environmental pH. Moreover, the presence of the carboxylic acid functional groups at the interface was evidenced by analyzing the adsorption/desorption capacity using methylene blue as a cationic dye model. The results demonstrated that increasing the acrylic acid in the microwrinkled hydrogel effectively improved the adsorption and release capacity and the ability of the carboxylic groups to establish ionic interactions with methylene blue. Finally, the role of the acrylic acid groups and the surface topography (smooth or wrinkled) on the final antibacterial properties were investigated, demonstrating their efficacy against both gram-positive and gram-negative bacteria model strains (E. coli and S. Aureus). According to our findings, microwrinkled hydrogels presented excellent antibacterial properties improving the results obtained for planar (smooth) hydrogels.

scholarly journals Preparation and Characterization of(I2)nSensitized NanoporousTiO2with Enhanced Photocatalytic Activity under Visible-Light Irradiation

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Juzheng Zhang ◽  
Xin Liu ◽  
Shanmin Gao ◽  
Quanwen Liu ◽  
Baibiao Huang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Chemical Properties ◽  
Reaction Model ◽  
Raw Material ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Adsorption Desorption

A yellow/brown powder of(I2)nsensitized nanoporous TiO2was obtained via an hydrolysis with TiCl4and iodine hydrosol as raw material. I2nanoparticles in the hydrosol were used as seeds to initiate the nucleation of a precursory TiO2shell. The hybridized jumbles were further calcinated at different temperatures. The structure, crystallinity, morphology, and other physical-chemical properties of the samples are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2adsorption-desorption isotherms measurements, and UV-vis diffuse reflectance spectroscopy (DRS). The formation mechanism of these(I2)nsensitized nanoporous TiO2is discussed. Methylene blue solutions were used as model wastewater to evaluate the visible light photocatalytic activity of the samples. The results indicate that iodine can exist even in high-temperature calcination for iodine being encapsulated in the nanocavities inside TiO2. The degradation of methylene blue (MB) accorded with the first-order reaction model.

scholarly journals Preparation and Characterization of Chabazite from Construction Waste and Application as an Adsorbent for Methylene Blue

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xue Song ◽  
Yingming Zhang ◽  
Xiangke Cui ◽  
Fangfang Liu ◽  
Hailiang Zhao
Keyword(s):  
Methylene Blue ◽  
Removal Rate ◽  
Synthesis Method ◽  
Chemical Properties ◽  
Maximum Adsorption Capacity ◽  
Building Projects ◽  
Construction Waste ◽  
Alkali Fusion ◽  
Adsorption Desorption ◽  
Physical And Chemical

Construction waste, produced from building projects, was utilized to prepare chabazite by alkali fusion hydrothermal synthesis method. The synthesized chabazite was used as an adsorbent for the removal of methylene blue (MB). XRD, FTIR, and N2 adsorption/desorption curves were adopted to describe the physical and chemical properties of the samples. The results show that the synthesized chabazite possesses crystalline structure, typical functional groups, and large specific surface area of 421.34 m2 g-1. Adsorption isotherms and kinetic curves show that the adsorption process follows the Langmuir model and pseudo-second-order kinetics model. The maximum adsorption capacity of MB on the synthesized chabazite reaches up to 129.18 mg g-1 at 298 K, which is about 16 times that of construction waste. The removal rate of MB reaches more than 90%, and the adsorbed amount is about 35 mg g-1 after 1 h at 298 K. Thermodynamic parameters, namely Δ H , Δ S , and Δ G of -12.83 kJ mol-1, -27.37 J mol-1 K-1, and -4.68 kJ mol-1 at 298 K, respectively, indicate that the adsorption of MB on the chabazite is physical, orderliness-tended, and spontaneous process. Moreover, the synthesized chabazite has a good property of regeneration and reuse. The results indicate that using construction waste to prepare chabazite in application as an adsorbent is feasible, which provides a novel and environment-friendly way for recycling construction waste.

scholarly journals Development of the technology for obtaining new hydrogel materials based on acrylic monomers

2017 ◽  
pp. 20-29
Author(s):  
Nazerke Nurabay ◽  
M. Abutalip ◽  
Raikhan Rakhmetullayeva ◽  
Grigoriy Mun
Keyword(s):  
Acrylic Acid ◽  
Drug Carrier ◽  
Antibacterial Properties ◽  
Homogeneous Solution ◽  
Radical Copolymerization ◽  
Water Soluble ◽  
Effect Of Temperature ◽  
Stimuli Responsive ◽  
Scanning Calorimetry ◽  
Smart Water

Smart water-soluble polymers and hydrogels are capable to reversibly react to insignificant changes of the medium properties (pH, temperature, ionic strength, a presence of some substances, illumination, electric field). The reacting of a system is visible to the naked eye (the formation of a new phase in a homogeneous solution, or compression of the hydrogel). The properties of such polymers and hydrogels are considered. For the first time, the stimuli-responsive polymeric hydrogels based on N-isopropylacrylamide (NIPAAM), 2-hydroxyethyl acrylate (HEA) and acrylic acid (AA) have been synthesized by free initiation of radical copolymerization. The purpose of the research is to obtain stimuli-responsive cross-linked terpolymers based on N-isopropylacrylamide, 2-hydroxyethyl acrylate and acrylic acid and study their physicochemical properties. The physicochemical methods such as scanning electron microscopy, differential scanning calorimetry, infrared spectroscopy, gravimetry, cathetometric and thermogravimetric analyses were used in this study. To determine the thermal and pH – sensitivity of the modified copolymer, the effect of temperature on the NIPAAM-НEA-AA nets (in different pH media) was studied. They are characterized by a thermally induced collapse and a dependence on a medium pH. The interaction of copolymers with drugs such as lincomycin and gentamicin was studied for using the new copolymers as a drug carrier. To study the antibacterial properties and the transportation of physiologically active substances of hydrogel, the elimination of specially prepared bacteria by hydrogels with various medicinal ingredients were conducted.

Exhibition of novel photocatalytic activity and photoluminescence properties with high inhibition towards bacterial growth by hydrothermally grown ZnO nanorods

2020 ◽  
Vol 16 ◽  
Author(s):  
Nihar Ranjan Panda ◽  
Dojalisa Sahu
Keyword(s):  
Methylene Blue ◽  
Bacterial Growth ◽  
Organic Dyes ◽  
Zno Nanorods ◽  
Antibacterial Properties ◽  
Crystallographic Structure ◽  
Inhibition Activity ◽  
Electron Microscopic ◽  
Skin Bacteria ◽  
High Inhibition

Background: Metal oxide nanomaterial such as; ZnO shows novel structural, optical, electrical and antibacterial properties due to wide band gap (3.37 eV) and high excitonic binding energy (60 meV). Probing these inherent properties of nanosized ZnO with different morphology has generated new interest among researchers Objective: To investigate the size dependent functional attributes, ZnO nanorods were prepared by hydrothermal method and the photocatalytic (PC) efficiency was studied. The photoluminescence (PL) property of ZnO nanorods was also studied by recording the emission spectrum under photo-excitation. These nanorods (NRs) were coated on cotton fabric to study the effectiveness of these NRs in defending and inhibiting the growth of different bacteria Methods: The crystallographic structure and morphology of the ZnO samples were investigated by X-ray diffraction (XRD) and field emission scanning electron microscopic (FESEM) measurements. PL measurement at room temperature was undertaken by exciting the sample with light of wavelength 350 nm. The PC property of ZnO NRs was studied in degrading organic dyes like methylene blue. Bacteria like Staphylococcus aureus, Escherichia coli and Bacillus subtilis were cultured and the inhibition of growth of these bacteria was studied by the application of ZnO. To enhance the microbe defence mechanism of fabric, we coated these NRs on fabric test samples and investigated the bacterial growth on it. Results: XRD and FESEM studies reveal the dimension of the synthesized products in nano range. These nanorods are of high density and surface roughness as per the FESEM study. PL measurement shows the presence of strong UV emission at 382 nm with defect emissions in the blue-green region opening up the path for ZnO to be used in fabrication of optoelectronic devices. PC study reveals that 89% degradation of methylene blue (MB) dye is achievable in 180 min using these ZnO catalysts. The anti-bacterial study shows that the minimum inhibitory concentration (MIC) of ZnO nanorods coated on the fabric against S. aureus is found to be 3.5 mg/ml which is the minimum as compared to E. coli (7.5 mg/ml) and B. subtilis (5.5 mg/ml). The study further enunciates that fabric coated with ZnO samples exhibited considerably high inhibition activity toward S. aureus. Conclusion: The study shows that ZnO NRs can be effectively used for fabrication of UV-LASER/LED. Photocatalytic efficiency of ZnO will be useful for degradation of organic dyes controlling environment pollution. It further enunciates that fabric coated with ZnO samples exhibited considerably high inhibition activity toward S. aureus (skin bacteria) which will be helpful in defending microbes if used in surgical cotton bandages

Reactions of macroions with ester and carboxylic groups of polymers

1987 ◽  
Vol 52 (9) ◽  
pp. 2194-2203
Author(s):  
Miloslav Kučera ◽  
Dušan Kimmer ◽  
Karla Majerová ◽  
Josef Majer
Keyword(s):  
Maleic Anhydride ◽  
Acrylic Acid ◽  
Methyl Methacrylate ◽  
Bond Formation ◽  
Covalent Bond ◽  
The Other ◽  
Poly Methyl Methacrylate ◽  
Other Hand ◽  
Carboxylic Groups ◽  
Poly Acrylic Acid

In the reaction of dianions with poly(methyl methacrylate), only an insignificant amount of insoluble crosslinked product is obtained. If, however, the concentration of grafting dianions approaches that of ester groups, the amount of poly(methyl methacrylate) which may thus be crosslinked becomes quite significant. Dications, too, can bring about crosslinking of only an insignificant number of poly(methyl methacrylate) chains. Carboxylic groups in poly(acrylic acid) react with dianions and dications in an anhydrous medium similarly to ester groups. On the other hand, in the presence of a cocatalytic amount of water dications are more readily bound to carboxylic groups, forming a covalent bond. The relatively highest efficiency was observed in the bond formation between dication and the poly[styrene-alt-(maleic anhydride)], both in an anhydrous medium and in the presence of H2O.

scholarly journals Enhanced Conductivity and Antibacterial Behavior of Cotton via the Electroless Deposition of Silver

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4731
Author(s):  
Changkun Liu ◽  
Dan Liao ◽  
Fuqing Ma ◽  
Zenan Huang ◽  
Ji’an Liu ◽  
...  
Keyword(s):  
Electroless Deposition ◽  
Deposition Time ◽  
Antibacterial Properties ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
High Antibacterial Activity ◽  
Physical And Chemical ◽  
And Staphylococcus Aureus ◽  
Enhanced Conductivity ◽  
And Chemical Properties

In this study, the surface-initiated atom transfer radical polymerization (SI-ATRP) technique and electroless deposition of silver (Ag) were used to prepare a novel multi-functional cotton (Cotton-Ag), possessing both conductive and antibacterial behaviors. It was found that the optimal electroless deposition time was 20 min for a weight gain of 40.4%. The physical and chemical properties of Cotton-Ag were investigated. It was found that Cotton-Ag was conductive and showed much lower electrical resistance, compared to the pristine cotton. The antibacterial properties of Cotton-Ag were also explored, and high antibacterial activity against both Escherichia coli and Staphylococcus aureus was observed.

scholarly journals Stimuli responsive dynamic transformations in supramolecular gels

2021 ◽  
Author(s):  
Santanu Panja ◽  
Dave J. Adams
Keyword(s):  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Stimuli Responsive ◽  
Dynamic Changes ◽  
Supramolecular Gels ◽  
Self Assembled ◽  
Physical And Chemical ◽  
And Chemical Properties

Stimuli responsive dynamic changes in the networks of self-assembled gels result in an alteration of physical and chemical properties of the gel with time.

scholarly journals Metal-Organic Framework-Based Stimuli-Responsive Polymers

2021 ◽  
Vol 5 (4) ◽  
pp. 101
Author(s):  
Menglian Wei ◽  
Yu Wan ◽  
Xueji Zhang
Keyword(s):  
Metal Organic Framework ◽  
Chemical Properties ◽  
Stimuli Responsive ◽  
Guest Molecules ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Reversible Phase Transition ◽  
Metal Organic ◽  
External Stimuli ◽  
Organic Framework

Metal-organic framework (MOF) based stimuli-responsive polymers (coordination polymers) exhibit reversible phase-transition behavior and demonstrate attractive properties that are capable of altering physical and/or chemical properties upon exposure to external stimuli, including pH, temperature, ions, etc., in a dynamic fashion. Thus, their conformational change can be imitated by the adsorption/desorption of target analytes (guest molecules), temperature or pressure changes, and electromagnetic field manipulation. MOF-based stimuli responsive polymers have received great attention due to their advanced optical properties and variety of applications. Herein, we summarized some recent progress on MOF-based stimuli-responsive polymers (SRPs) classified by physical and chemical responsiveness, including temperature, pressure, electricity, pH, metal ions, gases, alcohol and multi-targets.

Study on Relationship between Structure and Properties of Polycarboxylate Superplasticizer

2012 ◽  
Vol 487 ◽  
pp. 43-47
Author(s):  
Sheng Hua Lv ◽  
Di Li ◽  
Qiang Cao
Keyword(s):  
Acrylic Acid ◽  
Zeta Potential ◽  
Ethyl Ester ◽  
Functional Groups ◽  
Cement Paste ◽  
Ethyl Acrylate ◽  
Structure And Properties ◽  
Polycarboxylate Superplasticizer ◽  
Carboxylic Groups

A polycarboxylate superplasticizer (PCs) was synthesized by copolymerization of allyl polyoxyethylene ethers (APE), acrylic acid (AA), sodium methylallyl Sulfonate (SMAS) and ethyl acrylate (EA). The effect of functional groups and branch chain on PCs properties was investigated by the test of fluidity of cement paste, retardation performance and Zeta potential of cement particles. The results showed that carboxylic groups and ethyl ester groups can improve water reducing ratio and fluidity of cement paste, and the sulfonic groups has an important contributiion to retardation performance of PCs.

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