Morphology, Rheological and Mechanical Properties of Isotropic and Anisotropic PP/rPET/GnP Nanocomposite Samples

The effect of graphene nanoplatelets (GnPs) on the morphology, rheological, and mechanical properties of isotropic and anisotropic polypropylene (PP)/recycled polyethylene terephthalate (rPET)-based nanocomposite are reported. All the samples were prepared by melt mixing. PP/rPET and PP/rPET/GnP isotropic sheets were prepared by compression molding, whereas the anisotropic fibers were spun using a drawing module of a capillary viscometer. The results obtained showed that the viscosity of the blend is reduced by the presence of GnP due to the lubricating effect of the graphene platelets. However, the Cox–Merz rule is not respected. Compared to the PP/rPET blend, the GnP led to a slight increase in the elastic modulus. However, it causes a slight decrease in elongation at break. Morphological analysis revealed a poor adhesion between the PP and PET phases. Moreover, GnPs distribute around the droplets of the PET phase with a honey-like appearance. Finally, the effect of the orientation on both systems gives rise not only to fibers with higher modulus values, but also with high deformability and a fibrillar morphology of the dispersed PET phase. A fragile-ductile transition driven by the orientation was observed in both systems.

Engineered osteoclasts as living treatment materials for heterotopic ossification therapy

Osteoclasts (OCs), the only cells capable of remodeling bone, can demineralize calcium minerals biologically. Naive OCs have limitations for the removal of ectopic calcification, such as in heterotopic ossification (HO), due to their restricted activity, migration and poor adhesion to sites of ectopic calcification. HO is the formation of pathological mature bone within extraskeletal soft tissues, and there are currently no reliable methods for removing these unexpected calcified plaques. In the present study, we develop a chemical approach to modify OCs with tetracycline (TC) to produce engineered OCs (TC-OCs) with an enhanced capacity for targeting and adhering to ectopic calcified tissue due to a broad affinity for calcium minerals. Unlike naive OCs, TC-OCs are able to effectively remove HO both in vitro and in vivo. This achievement indicates that HO can be reversed using modified OCs and holds promise for engineering cells as “living treatment agents” for cell therapy.

Recycling of WEEE Plastics Waste in Mortar: The Effects on Mechanical Properties

This work focused on the recycling of WEEE plastic waste as a partial substitute for aggregate in light mortars. The plastic mix, provided by the IREN group, was used as a replacement of aggregate in 15, 30, 45, 60, 75, and 90%vol in mortars. Worsening of the mechanical performance of around 50% was detected already at only 15%vol of mineral aggregate substituted with plastic waste. The explanation of this phenomenon was found in both the scarce mechanical properties of the used plastic and in the poor adhesion between matrix and plastics that resulted in extra-porosity formation, as also demonstrated by comparing the results with several models in the literature. However, the use of plastic waste as a partial replacement of natural aggregate contributes to the preservation of natural resources and, in any case, does not limit the application of these materials in non-structural applications.

In-situ-grown silver–polymer framework with coordination complexes for functional artificial tissues

Sensorized actuators are critical to imitate proprio-/exteroception properties of biological neuromuscular systems. Existing add-on approaches, which physically blend heterogeneous sensor/actuator components, fall short of yielding satisfactory solutions, considering their suboptimal interfaces, poor adhesion, and electronic/mechanical property mismatch. Here, we report a single homogeneous material comprising seamless sensing-actuation unification properties at nano-/molecule levels, in which built-in sensing functions originate from the actuator architecture itself. In-situ-grown silver nanoparticles and metal-ligand complexes cooperatively create a silver–polymer framework (SPF) that is stretchable (1200%), conductive (0.076 S/m), and strong (0.76 MPa in-strength). SPF displays concomitant multimodal sensing (mechanical and thermal cues) and sensorized actuation capabilities, which include proprio-deformation and external stimuli perceptions (simultaneous with load-lifting ability up to 3700× of own weight). In view of its human somatosensitive muscular systems imitative functionality, the reported SPFs bode well for use with next generation functional tissues including artificial skins, human-machine interfaces, self-sensing robots, and otherwise dynamic materials.

Mussel-Inspired Catechol Functionalisation as a Strategy to Enhance Biomaterial Adhesion: A Systematic Review

Biomaterials have long been explored in regenerative medicine strategies for the repair or replacement of damaged organs and tissues, due to their biocompatibility, versatile physicochemical properties and tuneable mechanical cues capable of matching those of native tissues. However, poor adhesion under wet conditions (such as those found in tissues) has thus far limited their wider application. Indeed, despite its favourable physicochemical properties, facile gelation and biocompatibility, gellan gum (GG)-based hydrogels lack the tissue adhesiveness required for effective clinical use. Aiming at assessing whether substitution of GG by dopamine (DA) could be a suitable approach to overcome this problem, database searches were conducted on PubMed® and Embase® up to 2 March 2021, for studies using biomaterials covalently modified with a catechol-containing substituent conferring improved adhesion properties. In this regard, a total of 47 reports (out of 700 manuscripts, ~6.7%) were found to comply with the search/selection criteria, the majority of which (34/47, ~72%) were describing the modification of natural polymers, such as chitosan (11/47, ~23%) and hyaluronic acid (6/47, ~13%); conjugation of dopamine (as catechol “donor”) via carbodiimide coupling chemistry was also predominant. Importantly, modification with DA did not impact the biocompatibility and mechanical properties of the biomaterials and resulting hydrogels. Overall, there is ample evidence in the literature that the bioinspired substitution of polymers of natural and synthetic origin by DA or other catechol moieties greatly improves adhesion to biological tissues (and other inorganic surfaces).

Analisis Pengendalian Kualitas Bahan Baku Acrylic Resin Pada Produk Spray Paint di PT X

Thermo Plastic Acrylic resin has an important role in the manufacture of spray paint, namely as a binder or binder. The resin in paint has a function as a film formation, has adhesion to the substrate as well as pigment binders and additives, so that to produce a spray paint with good quality mechanical properties, PT X must be selective in controlling the quality of the raw material for Thermo Plasic Acrylic Resin. The purpose of this study was to determine the problems faced by PT X related to the quality of Thermo Plastic Acrylic Resin raw materials, to identify the most dominant factors affecting the quality of these raw materials and to formulate the most appropriate solutions to be applied in improving the quality of these raw materials. This research uses observation, interview, and literature study methods. Sources of data came from stakeholders and quality control staff of PT X. This study used check sheets, histogram diagrams, u-control maps, and fishbone diagrams to complete the analysis process. From the test results of the Thermoplastic Acrylic Resin raw material, it is known that the factor that causes rejection is due to adhesion, namely 53.57%, gloss 33.33%, and dry touch 13.10%, all three of the total raw materials that are rejected when the raw material is applied in form paint and spray on the film plate. The most dominant cause of reject was poor adhesion, namely 53.57% of the total reject raw materials.

Interfacial Adhesion and Microstructure of Epoxy/Aluminium Particulate Nanocomposites

Fibres anisotropy and their poor adhesion to the epoxy matrix are challenges in developing polymeric epoxy composite for structural applications. Filling of epoxy with reinforcing particles has potential for producing isotropic composites. In this study, epoxy-aluminium particulate composites were developed through combined-stir-techniques. Their interfacial adhesion and microstructural properties were examined. Results obtained indicated bonding of aluminium particles to epoxy through bidentate coordinate bond. Variations observed in the Fourier Transform Infrared spectrographs (FTIR) of both composites’ grades confirm discrepancies in interactions of aluminium micro and nanoparticles with epoxy. A good interfacial adhesion of aluminium nanoparticle with epoxy established by both optical and scanning electron microscopes is an indication of good mechanical performance of the epoxy composites.

Interface Characteristics and Anticorrosion Performances of Cold Galvanizing Coatings Incorporated with γ-chloropropyl Triethoxysilane on Hot-Dip Galvanized Steel

The cold galvanizing coatings (CGCs) are used to repair old hot-dip galvanized steel (HDG) in numerous anticorrosion engineering, but poor adhesion of the CGC restricts its large-scale applications in the industries. For the purpose of overcoming the weak adhesion problems of the CGC on HDG, γ-chloropropyl triethoxysilane (CPTES) was added directly into cold galvanizing coatings (CPTES/CGC). Interface characteristics and related corrosion protection behaviors were investigated by the pull-off adhesion test, water contact angle measurements, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and electrochemical tests. The experimental results revealed that, there is an increase by 19.1% of the CPTES/CGC surface free energy when compared with that of CGC. In addition, Si–O–Si and Si–O–Zn bonds were found in the CPTES/CGC, which indicate new network structures formed inside the CPTES/CGC, between the interface of the CPTES/CGC and HDG substrate, resulting in dry adhesion, wet adhesion, and the cathodic protection time of CPTES/CGC increased by 50% and 200% and 300% respectively compared with the CGC.

Study on water stability of asphalt binder with medium weathered igneous rock

Aiming at the problems of weak acidity of medium weathered igneous rock around Nairobi, Kenya, poor adhesion with asphalt and poor water stability of asphalt binder, the article studied the use of anti-stripping agent, cement, hydrated Lime and other technical measures to improve the water stability of asphalt binder with medium weathered igneous rock. The results showed that the 48h Marshall residual stability of the benchmark asphalt binder without any measures was 78.5%, which did not meet the standard requirements. The Marshall residual stability of medium weathered igneous rock can be significantly improved by adding anti stripping agent, cement and hydrated Lime. After freeze-thaw cycles, the splitting tensile strength of the asphalt binder with medium weathered igneous rock decreased obviously, and the TSR values of the asphalt binder with anti-spalling measures from small to large were K-4, K-3, K-2, K-6 and K-5. The water stability of the medium weathered igneous rock asphalt binder mixed with anti-stripping agent alone had relatively poor durability, and the medium weathered igneous rock asphalt binder mixed with cement and anti-stripping agent had the strongest ability to resist deformation when immersed in water.

Topical 5% lidocaine patches for treating postherpetic neuralgia: a survey among nurses and patients

Introduction: Postherpetic neuralgia (PHN) is associated with moderate to severe pain with peripheral and central mechanisms. While there is no clear-cut first-line therapeutic approach to PHN pain control, lidocaine patches are frequently used as monotherapy or part of a multimodal pain regimen. Methods: An online survey, the first of its kind, was conducted among PHN patients (n = 153) and nurses (n = 151) in order to determine clinical and patient knowledge, attitudes and practices toward the lidocaine patch and current unmet needs. Results: Results of the survey indicated that PHN patients are prescribed a mean of 2.6 medications to control their PHN pain, including the lidocaine patch. There were negative responses related to the patches’ ability to adhere to the skin. Patients reported the use of tape to hold the patches in place and/or patches that detached completely, truncating the therapeutic dose period. Most nurses (53%) found the biggest obstacle to PHN pain control was noncompliance and 98% stated that reliable patch adhesion for the intended 12-hour application was “somewhat important” or “very important” for PHN pain control. Forty-five percent of nurses said that poor patient adherence to PHN analgesic regimens was related to poor adhesion of the lidocaine patch. Conclusion: A new bioequivalent lidocaine patch has been developed with better adhesive characteristics, nine-fold greater bioavailability, and improved form factor.