Recycling of Bovine Hair Waste Through the Design of a Compatibilizing Agent for Sustainable Thermoplastic Starch-Untreated Bovine Hair Composites.

Bovine hair waste was chemically modified to obtain a coupling agent (CA) for the compatibilization of thermoplastic starch (TPS)-unmodified bovine hair waste (UH) composites. The composites processed with CA presented improved tensile strength (3.5 MPa) compared to TPS-UH composites without CA (1.

Antibacterial Properties of Grape Seed Extract-Enriched Cellulose Hydrogels for Potential Dental Application: In Vitro Assay, Cytocompatibility, and Biocompatibility.

Hydrogels elaborated from spp. and enriched with grape seed extract (GSE) were investigated for tentative use in dental treatment. Cellulose-GSE hydrogels were elaborated with varying GSE contents from 10 to 50 wt%.

Effect of the Addition of PLA on the Thermal and Mechanical Properties of Reprocessed HDPE.

Amid the current environmental crisis caused by plastic accumulation, one of the proposed solutions to manage this problem is using biodegradable polymers. However, the impact of adding biodegradable polymers to the well-established circular economy of recyclable polymers, such as HDPE, has not been fully considered. Therefore, there is a need to reconsider the way we consume, dispose of, and manage biodegradable polymers after use.

Antibacterial Effect of Silver Nanoparticles against Oral Biofilms in Subjects with Motor and Intellectual Disabilities.

Background: Motor and intellectual disabilities (MIDs) represent a great challenge for maintaining general health due to physical and cognitive limitations, particularly in the maintenance and preservation of oral health. Silver nanoparticles (AgNPs) have emerged as a promising therapeutic tool for bacterial control, including oral biofilms; however, knowledge of the bactericidal effectiveness of oral biofilms from patients with MIDs is insufficient. This study aims to determine the antimicrobial effect of AgNPs on different oral biofilms taken from patients with and without MIDs.

Bactericidal Activity of Silver Nanoparticles on Oral Biofilms Related to Patients with and without Periodontal Disease.

Background And Objectives: Periodontal disease (PD) is a multifactorial oral disease regularly caused by bacterial biofilms. Silver nanoparticles (AgNP) have offered good antimicrobial activity; moreover, there is no available scientific information related to their antimicrobial effects in biofilms from patients with PD. This study reports the bactericidal activity of AgNP against oral biofilms related to PD.

Characterization and In Vivo Assay of Allantoin-Enriched Pectin Hydrogel for the Treatment of Skin Wounds.

This work describes a liquid allantoin-enriched pectin hydrogel with hydrophilic behavior that is supported by the presence of functional groups related to healing efficacy. A topical study shows the effect of the hydrogel application on surgically induced skin wound healing in a rat model. Contact angle measurements confirm hydrophilic behavior (11.

Study of Geopolymers Obtained from Wheat Husk Native to Northern Mexico.

Agro-industrial wastes such as wheat husk (WH) are renewable sources of organic and inorganic substances, including cellulose, lignin, and aluminosilicates, which can be transformed into advanced materials with high added value. The use of geopolymers is a strategy to take advantage of the inorganic substances by obtaining inorganic polymers, which have been used as additives, e.g.

Electrochemical Immunosensor Using Electroactive Carbon Nanohorns for Signal Amplification for the Rapid Detection of Carcinoembryonic Antigen.

In this work, a novel sandwich-type electrochemical immunosensor was developed for the quantitative detection of the carcinoembryonic antigen, an important tumor marker in clinical tests. The capture antibodies were immobilized on the surface of a gold disk electrode, while detection antibodies were attached to redox-tagged single-walled carbon nanohorns/thionine/AuNPs. Both types of antibody immobilization were carried out through Au-S bonds using the novel photochemical immobilization technique that ensures control over the orientation of the antibodies.

Sulfonated Block Copolymers: Synthesis, Chemical Modification, Self-Assembly Morphologies, and Recent Applications.

Scientific research based on the self-assembly behavior of block copolymers (BCs) comprising charged-neutral segments has emerged as a novel strategy mainly looking for the optimization of efficiency in the generation and storage of electrical energy. The sulfonation reaction re- presents one of the most commonly employed methodologies by scientific investigations to reach the desired amphiphilic character, leading to enough ion concentration to modify and control the entire self-assembly behavior of the BCs. Recently, several works have studied and exploited these changes, inducing improvement on the mechanical properties, ionic conduction capabilities, colloidal solubility, interface activity, and stabilization of dispersed particles, among others.

Silk Fibroin--Polyaniline Platform for the Design of Biocompatible-Electroactive Substrate.

The structural modification of biopolymers is a current strategy to develop materials with biomedical applications. Silk fibroin is a natural fiber derived from a protein produced by the silkworm () with biocompatible characteristics and excellent mechanical properties. This research reports the structural modification of silk fibroin by incorporating polyaniline chain grafts through a one-pot process (esterification reaction/oxidative polymerization).

Theoretical Study of Vinyl-Sulfonate Monomers and Their Effect as the Dopants of Polyaniline Dimers.

Establishing the structure-property relationships of monomers and polymers via theoretical chemistry is vital for designing new polymer structures with a specific application. Developing bifunctional monomers with selective polymerizable sites is one of the strategies employed to obtain complex polymeric systems. In this work, a theoretical study on anilinium 2-acrylamide-2-methyl-1-propanesulfonate (ani-AMPS) and anilinium 4-styrenesulfonate (ani-SS) monomers and their respective doped polyaniline dimer (PAni-d AMPS or PAni-d SS) was performed.

Brush-like Polyaniline with Optical and Electroactive Properties at Neutral pH and High Temperature.

In this research, a brush-like polyaniline (poly(2-acrylamide-2-methyl-1-propanesulfonate)--polyaniline)--poly(-vinylcarbazole) (BL PAni) was developed as a strategy to overcome the limited processability and dedoping above pH 4 of conventional polyaniline (PAni). For the BL PAni synthesis, RAFT polymerization (homopolymer), RAFT-mediated surfactant-free emulsion polymerization (block copolymer), and interfacial oxidative polymerization were applied to graft the PAni chains. NMR and FT-IR spectroscopies were performed to confirm the structural elucidation of the reaction pathways, while the thermal properties were analyzed by TGA and DSC.

Anti-Adherence and Antimicrobial Activities of Silver Nanoparticles against Serotypes and of on Orthodontic Appliances.

Background and Objectives: Streptococcus mutans (S. mutans) is the main microorganism associated with the presence of dental caries and specific serotypes of this bacteria have been related to several systemic diseases limiting general health. In orthodontics, white spot lesions (WSL), represent a great challenge for clinicians due to the great fluctuation of their prevalence and incidence during conventional orthodontic treatments.

Progress of Polyaniline Glucose Sensors for Diabetes Mellitus Management Utilizing Enzymatic and Non-Enzymatic Detection.

Glucose measurement is a fundamental tool in the daily care of Diabetes Mellitus (DM) patients and healthcare professionals. While there is an established market for glucose sensors, the rising number of DM cases has promoted intensive research to provide accurate systems for glucose monitoring. Polyaniline (PAni) is a conductive polymer with a linear conjugated backbone with sequences of single C-C and double C=C bonds.

Thermoplastic Starch-Based Blends with Improved Thermal and Thermomechanical Properties.

This research focused on the development of biomaterials based on cassava starch and corn starch and on the effect of the incorporation of polycaprolactone (PCL) on the thermal and thermomechanical properties of the blends. The results indicated partial compatibility in the blends, especially with cassava starch at a content of 20 wt% as reflected by the maintenance of tensile strength and elongation. In addition, the changes in the crystal quality of PCL and the displacement of the absorption bands of the carbonyl groups of PCL in the infrared (989-1000 cm), attributed to the formation of hydrogen bonds between these groups and the hydroxyl groups of starches, were also associated with compatibility.

Characterization and Topical Study of Aloe Vera Hydrogel on Wound-Healing Process.

Wound healing is fundamental to restore the tissue integrity. A topical study of the influence of Aloe vera hydrogel, formulated with 1,2-propanediol (propanediol) and triethanolamine (TEA), on the skin wound-healing process was investigated in female Wistar rats. FTIR spectroscopy confirms the presence of carboxylic acid and methyl ester carboxylate groups related with important compounds that confer the hydrogel a good interaction with proteins and growth factors.

Hydrogen bonding reversibility in poly(10,12-pentacosadiynoic acid)/titanium dioxide composite analyzed by infrared spectroscopy.

In this work, the chromatic behavior of a poly(10,12-pentacosadiinoic acid)/titanium dioxide (TiO) nanocomposite was studied. Infrared spectroscopy showed that above 55 °C the peak of the carboxyl groups undergoes a shift from 1690 cm (25-55° C) to 1710 cm (≥60 °C), which is reversible after cooling regardless of whether the sample was in the blue or red phase prior to heating. This indicates that the thermochromic behavior and the hydrogen bond shifting are not completely related, since the signal of the hydrogen bond is influenced by temperature, but is reversible; however, the color change is not.

Simultaneous Detection of Dihydroxybenzene Isomers Using Electrochemically Reduced Graphene Oxide-Carboxylated Carbon Nanotubes/Gold Nanoparticles Nanocomposite.

An electrochemical sensor based on electrochemically reduced graphene oxide (ErGO), carboxylated carbon nanotubes (cMWCNT), and gold nanoparticles (AuNPs) (GCE/ErGO-cMWCNT/AuNPs) was developed for the simultaneous detection of dihidroxybenzen isomers (DHB) hydroquinone (HQ), catechol (CC), and resorcinol (RS) using differential pulse voltammetry (DPV). The fabrication and optimization of the system were evaluated with Raman Spectroscopy, SEM, cyclic voltammetry, and DPV. Under optimized conditions, the GCE/ErGO-cMWCNT/AuNPs sensor exhibited a linear concentration range of 1.

Role of the Anilinium Ion on the Selective Polymerization of Anilinium 2-Acrylamide-2-methyl-1-propanesulfonate.

The development of anilinium 2-acrylamide-2-methyl-1-propanesulfonate (Ani-AMPS) monomer, confirmed by H NMR, C NMR, and FTIR, is systematically studied. Ani-AMPS contains two polymerizable functional groups, so it was submitted to selective polymerization either by free-radical or oxidative polymerization. Therefore, poly(anilinium 2-acrylamide-2-methyl-1-propanesulfonic) [Poly(Ani-AMPS)] and polyaniline doped with 2-acrylamide-2-methyl-1-propanesulfonic acid [PAni-AMPS] can be obtained.

Curing of Cellulose Hydrogels by UV Radiation for Mechanical Reinforcement.

The use of biomaterials as a replacement for thermoplastic polymers is an environmentally sound strategy. In this work, hydrogels of cellulose isolated from wheat husk were modified by UV irradiation (353 nm) to improve mechanical performance. The cellulose was dissolved with a solvent system -dimethylacetamide/lithium chloride (DMAc/LiCl).

Synthesis and Characterization of a Lignin-Styrene-Butyl Acrylate Based Composite.

In recent years, the pursuit of new polymer materials based on renewable raw materials has been intensified with the aim of reusing waste materials in sustainable processes. The synthesis of a lignin, styrene, and butyl acrylate based composite was carried out by a mass polymerization process. A series of four composites were prepared by varying the amount of lignin in 5, 10, 15, and 20 wt.

Synthesis of carbon black/polystyrene conductive nanocomposite. Pickering emulsion effect characterized by TEM.

In this study, carbon black/polystyrene electrically conductive composites were obtained by suspension polymerization technique. The composite was characterized using transmission electron microscopy, which indicated two outstanding features concerning to the carbon black; first, that the carbon particles were adsorbed onto the surface of the polystyrene particles, similarly as in the Pickering emulsion phenomenon and second, that the primary aggregate structure of the carbon black was significantly affected by the dispersion process. On the other hand, the composite resistivity was in the order of 200 Ωcm, which was attributed to the direct contact of primary carbon black particles (percolation) and not to the tunneling effect.

Theoretical evaluation of the order of reactivity of transfer agents utilized in RAFT polymerization: part 2: group R.

Density functional theory, DFT, PBE1PBE functional and 6-31+G(d,p) basis set in Gaussian 03 software were used in order to determine the reactivity order of the R group in RAFT agents used in the radical addition-fragmentation transfer polymerization, through the evaluation of reactivity parameters such as: global and local electronegativity, hardness, softness, and philicity. It was found that the reactivity order is governed by both the number and the composition of the substituent group (primary, secondary or tertiary); that is, the larger those parameters are the larger factors like steric hindrance, polar effects and electronic interchanges are, which favors the breaking of the C-S bond from the adduct radical, permitting the exit of the leaving radical and allowing, as a consequence, the fragmentation step in RAFT polymerization. Trisubstituted dithioesters with structure S = C(Z)S-R, where Z = Phenyl and R = C(CH(3))(2)CONH(2), C(CH3)2Ph or (CH(3))(2)C(6)H(8)OCH(3), in accordance with the previously exposed, presented the most favorable reactivity parameters.