Synthesis, characterization and properties of a novel environmentally friendly ternary hydrophilic copolymer

A novel environmentally friendly scale inhibitor was synthesized by the free radical polymerization of itaconic acid (IA), acrylamide (AM), and sodium p-styrene sulfonate (SSS). The structures of the copolymers were characterized using FTIR, UV, and ¹H-NMR, which proved successful in obtaining the expected target structures. The synthesis conditions such as monomer ratio, initiator dosage, titration time, and reaction temperature were optimized by the static scale inhibition method, and the expected polymeric scale inhibitor with a competent scale inhibition performance was obtained. The copolymer conversions at different temperatures were obtained indirectly by bromination titration, and the relationship between the molecular weight of the polymer and the scale inhibition performance at different reaction temperatures was also investigated by GPC. The results showed that the copolymer had a good ability to control calcium carbonate scaling, and the inhibition rate of CaCO₃ reached 84.7% at a dose of 30 mg L^-1. The microscopic morphology and structure of calcium scales were analyzed by SEM, FTIR, and XRD, and it was concluded that the copolymer could change the crystallization path of calcium carbonate from stable calcite to vaterite. That could be dispersed in water. The proposed inhibition mechanism suggests that surface complexation between polymer functional groups and Ca²⁺ leads to excellent solubility of the complexes. These findings suggest that the prepared green copolymers have great potential for oilfield applications.

Characterization of Electrospun Polysuccinimide-Dopamine Conjugates and Effect on Cell Viability and Uptake

Biocompatible nanofibrous systems made by electrospinning have been studied widely for pharmaceutical applications since they have a high specific surface and the capability to make the entrapped drug molecule amorphous, which increases bioavailability. By covalently conjugating drugs onto polymers, the degradation of the drug as well as the fast clearance from the circulation can be avoided. Although covalent polymer-drug conjugates have a lot of advantages, there is a lack of research focusing on their nano-formulation by electrospinning. In this study, polysuccinimide (PSI) based electrospun fibrous meshes conjugated with dopamine (DA) are prepared. Fiber diameter, mechanical properties, dissolution kinetics and membrane permeability are thoroughly investigated, as these are crucial for drug delivery and implantation. Dopamine release kinetics prove the prolonged release that influenced the viability and morphology of periodontal ligament stem cells (PDLSCs) and SH-SY5Y cells. The presence of dopamine receptors on both cell types is also demonstrated and the uptake of the conjugates is measured. According to flow cytometry analysis, the conjugates are internalized by both cell types, which is influenced by the chemical structure and physical properties. In conclusion, electrospinning of PSI-DA conjugates alters release kinetics, meanwhile, conjugated dopamine can play a key role in cellular uptake.

Metal ion chelation of poly(aspartic acid): From scale inhibition to therapeutic potentials

Poly(aspartic acid) (PASP) is a biodegradable, biocompatible water-soluble synthetic anionic polypeptide. PASP has shown a strong affinity and thus robust complexation with heavy and alkaline earth metal ions, from which several applications are currently benefiting, and several more could also originate. This paper discusses different areas where the ion chelation ability of PASP has thus far been exploited. Due to its calcium chelation ability, PASP prevents precipitation of calcium salts and hence is widely used as an effective scale inhibitor in industry. Due to potassium chelation, PASP prevents precipitation of potassium tartrate and is employed as an efficient and edible stabilizer for wine preservation. Due to iron chelation, PASP inhibits corrosion of steel surfaces in harsh environments. Due to chelation, PASP can also enhance stability of various colloidal systems that contain metal ions. The chelation ability of PASP alleviated the toxicity of heavy metals in Zebrafish, inhibited the formation of kidney stones and dissolved calcium phosphate which is the main mineral of the calcified vasculature. These findings and beyond, along with the biocompatibility and biodegradability of the polymer could direct future investigations towards chelation therapy by PASP and other novel and undiscovered areas where metal ions play a key role.

Fluorescent-Tagged Antiscalants-The New Materials for Scale Inhibition Mechanism Studies, Antiscalant Traceability and Antiscaling Efficacy Optimization during CaCO3 and CaSO4·2H2O Scale Formation

Equipment scaling leads to reduced production efficiency in a wide range of industrial applications worldwide. Various antiscaling agents are currently commonly used to mitigate this problem. However, irrespective of their long and successful application in water treatment technologies, little is known about the mechanisms of scale inhibition, particularly the localization of scale inhibitors on scale deposits. The lack of such knowledge is a limiting factor in the development of applications for antiscalants. Meanwhile, fluorescent fragments integrated into scale inhibitor molecules have provided a successful solution to the problem. The focus of this study is, therefore, on the synthesis and investigation of a novel fluorescent antiscalant: (2-(6-morpholino-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)yl)ethylazanediyl)bis(methylenephosphonic acid) (ADMP-F) which is an analog of the commercial antiscalant: aminotris(methylenephosphonic acid) (ATMP). ADMP-F has been found to effectively control the precipitation of CaCO₃ and CaSO₄ in solution and is a promising tracer for organophosphonate scale inhibitors. ADMP-F was compared with two other fluorescent antiscalants-polyacrylate (PAA-F1) and bisphosphonate (HEDP-F)-and was found to be highly effective: PAA-F1 > ADMP-F >> HEDP-F (CaCO₃) and PAA-F1 > ADMP-F > HEDP-F (CaSO₄·2H₂O). The visualization of the antiscalants on the deposits provides unique information on their location and reveals differences in the "antiscalant-deposit" interactions for scale inhibitors of different natures. For these reasons, a number of important refinements to the mechanisms of scale inhibition are proposed.

Green inhibitors reduce unwanted calcium carbonate precipitation: Implications for technical settings

Mineral scale deposits in water drainage and supply systems are a common and challenging issue, especially by clogging the water flow. The removal of such unwanted deposits is cost intensive arguing for case-specific and sustainable prevention strategies. In the present study, a novel on-site approach to prevent calcium carbonate (CaCO₃) scale formation was assessed in two road tunnel drainages: Application of the eco-friendly green inhibitor polyaspartate (PASP) caused (i) a significant inhibition of CaCO₃ precipitation, (ii) a more porous or even unconsolidated consistence of the deposits, and (iii) a shift from calcite to the metastable aragonite and vaterite polymorphs. Even relatively low PASP concentrations (1-33 mg/l) can significantly decrease CaCO₃ scale deposition, removing up to ∼7 t CaCO₃/year at an efficiency up to 84%. Application of PASP for water conditioning should also consider case-specific microbial activity effects, where consumption of PASP, e.g. by Leptothrix ochracea, can limit inhibition effects.

Poly(aspartic acid) in Biomedical Applications: From Polymerization, Modification, Properties, Degradation, and Biocompatibility to Applications

Poly(aspartic acid) (PASP) is an anionic polypeptide that is a highly versatile, biocompatible, and biodegradable polymer that fulfils key requirements for use in a wide variety of biomedical applications. The derivatives of PASP can be readily tailored via the amine-reactive precursor, poly(succinimide) (PSI), which opens up a large window of opportunity for the design and development of novel biomaterials. PASP also has a strong affinity with calcium ions, resulting in complexation, which has been exploited for bone targeting and biomineralization. In addition, recent studies have further verified the biocompatibility and biodegradability of PASP-based polymers, which is attributed to their protein-like structure. In light of growing interest in PASP and its derivatives, this paper presents a comprehensive review on their synthesis, characterization, modification, biodegradation, biocompatibility, and applications in biomedical areas.

Synthesis, characterization and performance evaluation of an environmentally benign scale inhibitor IA/AMPS co-polymer

An IA/AMPS co-polymer is a promising scale inhibitor applied to circulating cooling water systems against CaCO₃and CaSO₄.