Tetraethyleneglycol Diacrylate Research Articles

Soluble Fluorinated Cardo Copolyimide as an Effective Additive to Photopolymerizable Compositions Based on Di(meth)acrylates: Application for Highly Thermostable Primary Protective Coating of Silica Optical Fiber.

The development of photocurable compositions is in high demand for the manufacture of functional materials for electronics, optics, medicine, energy, etc. The properties of the final photo-cured material are primarily determined by the initial mixture, which needs to be tuned for each application. In this study we propose to use simple systems based on di(meth)acrylate, polyimide and photoinitiator for the preparation of new photo-curable compositions. It was established that a fluorinated cardo copolyimide (FCPI) based on 2,2-bis-(3,4-dicarboxydiphenyl)hexafluoropropane dianhydride, 9,9-bis-(4-aminophenyl)fluorene and 2,2-bis-(4-aminophenyl)hexafluoropropane (1.00:0.75:0.25 mol) has excellent solubility in di(met)acrylates. This made it possible to prepare solutions of FCPI in such monomers, to study the effect of FCPI on the kinetics of their photopolymerization in situ and the properties of the resulting polymers. According to the obtained data, the solutions of FCPI (23 wt.%) in 1,4-butanediol diacrylate (BDDA) and FCPI (15 wt.%) in tetraethylene glycol diacrylate were tested for the formation of the primary protective coatings of the silica optical fibers. It was found that the new coating of poly(BDDA-FCPI23%) can withstand prolonged annealing at 200 °C (72 h), which is comparable or superior to the known most thermally stable photo-curable coatings. The proposed approach can be applied to obtain other functional materials.

The Effect of Silane Acrylate Containing Ethylene Glycol Chains on the Adhesive Performance and Viscoelastic Behavior of Acrylic Pressure-Sensitive Adhesives for Flexible Displays.

In this study, novel silane acrylates, such as diethylene glycol diacrylate (DEGDA) and tetraethylene glycol diacrylate (TEGDA), containing ethylene glycol chains were synthesized and introduced into acrylic pressure-sensitive adhesives (PSAs) to regulate their peel strength and rheological properties. The synthesized silane acrylates effectively improved the cohesion and adhesive properties of the acrylic PSAs, even with only 1 wt% addition. In addition, the glass transition temperature and flexibility of acrylic PSAs were also affected by the increase in free volume induced by ethylene glycol chains. The silane acrylates also improved the viscoelasticity of the acrylic PSAs, which exhibited excellent recovery (62-96%) and stress relaxation (>90%) properties owing to the increased elasticity. Additionally, the acrylic PSAs prepared with the silane acrylates showed excellent optical properties (transmittance ≥ 90%, haze ≤ 1%) and exhibited behavior suitable for application in flexible displays from a comprehensive perspective.

The Effects of Cross-Linking Agents on the Mechanical Properties of Poly (Methyl Methacrylate) Resin.

Cross-linking agents are incorporated into denture base materials to improve their mechanical properties. This study investigated the effects of various cross-linking agents, with different cross-linking chain lengths and flexibilities, on the flexural strength, impact strength, and surface hardness of polymethyl methacrylate (PMMA). The cross-linking agents used were ethylene glycol dimethacrylate (EGDMA), tetraethylene glycol dimethacrylate (TEGDMA), tetraethylene glycol diacrylate (TEGDA), and polyethylene glycol dimethacrylate (PEGDMA). These agents were added to the methyl methacrylate (MMA) monomer component in concentrations of 5%, 10%, 15%, and 20% by volume and 10% by molecular weight. A total of 630 specimens, comprising 21 groups, were fabricated. Flexural strength and elastic modulus were assessed using a 3-point bending test, impact strength was measured via the Charpy type test, and surface Vickers hardness was determined. Statistical analyses were performed using the Kolmogorov-Smirnov Test, Kruskal-Wallis Test, Mann-Whitney U Test, and ANOVA with post hoc Tamhane test (p ≤ 0.05). No significant increase in flexural strength, elastic modulus, or impact strength was observed in the cross-linking groups compared to conventional PMMA. However, surface hardness values notably decreased with the addition of 5% to 20% PEGDMA. The incorporation of cross-linking agents in concentrations ranging from 5% to 15% led to an improvement in the mechanical properties of PMMA.

In-situ construction of tetraethylene glycol diacrylate based gel polymer electrolyte for long lifespan lithium metal batteries

Replacing the liquid electrolytes with polymer electrolytes is an irresistible trend to meet the application requirement of lithium metal batteries. However, for obtaining a better cycling performance, traditional polymer electrolytes typically need to be operated at high temperature, which limits the commercialization of next-generation lithium metal batteries. Here, a flexible gel polymer electrolyte (TGD-TCGG-PAN) is constructed in polyacrylonitrile (PAN) porous spinning membrane via the in-situ free radical polymerization. At 30 °C, the lithium-ion conductivity and lithium-ion transference number of TGD-TCGG-PAN are 1.57 × 10−4 S cm−1 and 0.72, respectively. The LFP|TGD-TCGG-PAN|Li battery can cycle at 3C for more than 700 cycles with a capacity retention rate of 95.02%. Compared with commercial PE membrane, application of PAN makes the TGD-TCGG-PAN perform a better thermal stability. This new process is a viable way for lithium metal batteries using gel polymer electrolyte.

Elaboration of capsules from Pickering double emulsion polymerization stabilized solely by cellulose nanocrystals

Pickering double oil-in-water-in-oil emulsions O/W/O were stabilized using solely cellulose nanocrystals (CNCs), which were modified by introducing surface brominated functions. The emulsions were formulated using only bio-friendly components, among which isopropyl myristate as oil phase, hydroxyl oligoethylene glycol methacrylate (OEGMA) as macromonomer, tetraethylene glycol diacrylate (TEGDA) as cross-linker, and CNCs as stabilizing particles. Formulation parameters could be tuned easily to modulate the fraction of inner emulsion droplets within the double emulsion drops or change the monomer(s) composition within the aqueous phase. The latter was further polymerized to synthesize matrix capsules. The obtained objects showed good resistance to the vacuum and were efficiently used as promising encapsulation vessels. Both hydrophobic and hydrophilic model dyes were encapsulated, with an encapsulation efficiency of about 90%.

Microwave-assisted oxidative coupling of thiols using polystyrene supported bromoderivatives of 2-oxazolidone

Polymer-supported reagents have become popular in synthetic organic chemistry over the past decades. But the kinetics of polymer-supported reactions is slow compared to solution phase synthesis because of the poor diffusion of the reactants through the macromolecular polymer matrix. This difficulty can be reduced to a great extent by performing polymer-supported reactions under microwave (MW) conditions. The present work is focussed on the design and development of an innovative, powerful, MW stable and recyclable polymeric reagent prepared by attaching bromoderivative of 2-oxazolidone into the macromolecular matrix of polystyrene. 3% cross-linked polystyrene was prepared by free radical aqueous suspension polymerization technique using tetra ethylene glycol diacrylate as the cross-linking agent and the resulting beads were functionalized by chloromethylation followed by reaction with 2-oxazolidone. Bromine functionality is introduced into the polymer by treating with bromine in carbon tetrachloride. The synthetic utility of the prepared polymeric reagent was demonstrated by the oxidative coupling of thiols to disulfides under MW irradiation. No over oxidation was observed in this protocol and the utilization of polystyrene support simplifies work up and product isolation. The synthesised polymeric reagent displayed good cyclic stability up to five cycles without any substantial decrease in bromine content and satisfactory storage stability under normal laboratory condition. Moreover this may be the first report that uses MW energy for the oxidation of thiols to disulfides using polymer-supported reagents. [Formula: see text]

Localized Water‐In‐Salt Electrolyte for Aqueous Lithium‐Ion Batteries

AbstractWater‐in‐salt (WIS) electrolytes using super‐concentrated organic lithium (Li) salts are of interest for aqueous Li‐ion batteries. However, the high salt cost, high viscosity, poor wettability, and environmental hazards remain a great challenge. Herein, we present a localized water‐in‐salt (LWIS) electrolyte based on low‐cost lithium nitrate (LiNO3) salt and 1,5‐pentanediol (PD) as inert diluent. The addition of PD maintains the solvation structure of the WIS electrolyte, improves the electrolyte stability via hydrogen‐bonding interactions with water and NO3− molecules, and reduces the total salt concentration. By in situ gelling the LWIS electrolyte with tetraethylene glycol diacrylate (TEGDA) monomer, the electrolyte stability window can be further expanded to 3.0 V. The as‐developed Mo6S8|LWIS gel electrolyte|LiMn2O4 (LMO) batteries delivered outstanding cycling performance with an average Coulombic efficiency of 98.53 % after 250 cycles at 1 C.

Localized Water-In-Salt Electrolyte for Aqueous Lithium-Ion Batteries.

Water-in-salt (WIS) electrolytes using super-concentrated organic lithium (Li) salts are of interest for aqueous Li-ion batteries. However, the high salt cost, high viscosity, poor wettability, and environmental hazards remain a great challenge. Herein, we present a localized water-in-salt (LWIS) electrolyte based on low-cost lithium nitrate (LiNO3 ) salt and 1,5-pentanediol (PD) as inert diluent. The addition of PD maintains the solvation structure of the WIS electrolyte, improves the electrolyte stability via hydrogen-bonding interactions with water and NO3 - molecules, and reduces the total salt concentration. By in situ gelling the LWIS electrolyte with tetraethylene glycol diacrylate (TEGDA) monomer, the electrolyte stability window can be further expanded to 3.0 V. The as-developed Mo6 S8 |LWIS gel electrolyte|LiMn2 O4 (LMO) batteries delivered outstanding cycling performance with an average Coulombic efficiency of 98.53 % after 250 cycles at 1 C.

Polystyrene-supported bromoderivative of 2-pyrrolidone: synthesis, characterization and application in microwave-assisted bromination reactions

A novel, microwave safe and recyclable polymeric reagent was prepared by anchoring bromoderivative of 2-pyrrolidone in the polymer matrix of 3% tetraethyleneglycol diacrylate cross-linked polystyrene. The synthetic utility of the prepared polymeric reagent was demonstrated by the efficient bromination of unsaturated compounds, activated aromatic compounds and also for the α-bromination of ketones under microwave activation. Operational simplicity, moderate to excellent yield of the products, shorter reaction time and dry reaction medium are the foremost attraction of this protocol. Moreover, the synthesized functional polymer was stable under standard laboratory conditions and can be kept for several months without any significant loss of activity.

Biodegradable zwitterionic poly(carboxybetaine) microgel for sustained delivery of antibodies with extended stability and preserved function.

Many recent innovative treatments are based on monoclonal antibodies (mAbs) and other protein therapies. Nevertheless, sustained subcutaneous, oral or pulmonary delivery of such therapeutics is limited by the poor stability, short half-life, and non-specific interactions between the antibody (Ab) and delivery vehicle. Protein stabilizers (osmolytes) such as carboxybetaine can prevent non-specific interactions within proteins. In this work, a biodegradable zwitterionic poly(carboxybetaine), pCB, based microgel covalently crosslinked with tetra(ethylene glycol) diacrylate (TTEGDA) was synthesized for Ab encapsulation. The resulting microgels were characterized via FTIR, diffusion NMR, small-angle neutron scattering (SANS), and cell culture studies. The microgels were found to contain up to 97.5% water content and showed excellent degradability that can be tuned with crosslinking density. Cell compatibility of the microgel was studied by assessing the toxicity and immunogenicity in vitro. Cells exposed to microgel showed complete viability and no pro-inflammatory secretion of interleukin 6 (IL6) or tumor necrosis factor-alpha (TNFα). Microgel was loaded with Immunoglobulin G (as a model Ab), using a post-fabrication loading technique, and Ab sustained release from microgels of varying crosslinking densities was studied. The released Abs (especially from the high crosslinked microgels) proved to be completely active and able to bind with Ab receptors. This study opens a new horizon for scientists to use such a platform for local delivery of Abs to the desired target with minimized non-specific interactions.

Superabsorbent composites (SACs) based on xanthan gum-g-poly (itaconic acid)/kaolinite

In this present investigation, crosslinked polyitaconic acid (PIA) was grafted onto natural polysaccharides xanthan gum and inorganic clay kaolinite using free radical polymerization in an inert atmosphere using FTIR ammonium persulfate (APS) as an initiator and Tetra (ethylene glycol) diacrylate (TEGDA) as a crosslinking agent. Scanning electron microscopy and Fourier transform infrared spectra techniques were used to characterized for structure SAPs. The effect of various parameters which include APS, TEGDA, neutralizing degree, kaolinite contents, and xanthan gum was investigated. The results indicate that PIA successfully grafted onto xanthan gum and a 3D structure was formed. The results indicated with an increasing Xanthan gum/kaolin weight ratio, swelling capacity, and gel content.

Hybrid separator containing reactive, nanostructured alumina promoting in-situ gel electrolyte formation for lithium-ion batteries with good cycling stability and enhanced safety

The thermal instability of conventional polyolefin separators and the high flammability of organic electrolytes are the primary safety-related concerns of high-energy-density lithium-ion batteries. To address these issues, reactive Al2O3 nanostructured materials are coated onto a polyethylene (PE) separator to promote the formation of gel electrolyte and enhance the thermal stability of the separator. The Al2O3 nanostructured materials are surface-treated by 3-methacryloxypropyl trimethoxysilane to induce radical polymerization with tetra(ethylene glycol) diacrylate (TEGDA) in liquid electrolyte. The three-dimensional network formed by cross-linking reactive alumina nanostructured materials and TEGDA reduces the electrolyte leakage from the cell and enhances the interfacial adhesion between separator and electrodes. Thermal shrinkage of the reactive alumina-coated separator is also significantly reduced at 140 °C, providing enhanced thermal stability. In addition to improved thermal safety, lithium-ion cells employing a reactive alumina-coated PE separator exhibit stable cycling at both ambient and high temperatures.

Re‐Engineering Poly(Acrylic Acid) Binder toward Optimized Electrochemical Performance for Silicon Lithium‐Ion Batteries: Branching Architecture Leads to Balanced Properties of Polymeric Binders

AbstractSilicon is a promising anode material for lithium‐ion batteries with its superior capacity. However, the drastic volume changes during lithiation/delithiation cycles hinder the cycling performance, resulting in particle pulverization, conductivity loss, and an unstable electrode–electrolyte interface. Herein, a series of synthetic polymeric binders, poly(acrylic acid‐co‐tetra(ethylene glycol) diacrylate)—featuring a poly(acrylic acid) (PAA) backbone branched via tetra(ethylene glycol) diacrylate (TEGDA)—are developed that edge toward evidencing well‐balanced properties to confront capacity fading in Si‐based electrodes. The incorporation of ether chain not only leads to the branching architecture of the PAA backbone, thus affecting its mechanical properties, but also promotes the conductivity of Li ions. As a result, a synergistic performance improvement is observed in both half and full cells. The best‐performing cell using a branched PAA binder (bPAA) with a feeding molar ratio ([TEGDA]:[acrylic acid(AA)]) of 0.2 results in a 10% increase in initial capacity and a 31% increase in capacity retention over 100 cycles compared to the linear PAA cell. The cross‐sectional microscopic images of the cycled electrodes reveal that bPAA binders can drastically reduce the electrode expansion. This improvement results from the well‐balanced properties of the polymer design, which could guide further development for more advanced binder materials.

Distribution of water states within Poly(HEMA-co-HPMA)-based hydrogels

The distribution of water states within hydrogels is implicated in their biotechnical performance. Formulated synthetic hydrogels based on poly(2-hydroxyethylmethacrylate-co-N-(2-hydroxypropyl) methacrylamide) [poly(HEMA-co-HPMA)] of varying cross-linker concentration and monomer mole ratio were studied for their degree of hydration and water distribution. Cross-linker concentrations of 0.1, 0.5, 1.0, and 3.0 mol% tetraethylene glycol diacrylate (TEGDA) were studied when the HEMA:HPMA mole ratios were selected to be 1:0 and 4:1. Additionally, the cross-linker concentration of 1.0 mol% TEGDA was studied in detail when the HEMA:HPMA ratio was selected to be 1:1. The degree of hydration was determined by gravimetry. The distribution among water states was determined from Gaussian deconvolution of the DSC thermograms and use of ΔHf(T) for T < 0 °C. Both the cross-linker concentration and the HEMA:HPMA mole ratio served to alter degree of hydration and the distribution among freezable free, freezable bound and non-freezable bound water states. The presence of 20% and 50% HPMA served to increase total hydration relative to poly(HEMA) (0% HPMA) by 25% and 46%, respectively at 1 mol% TEGDA. The freezable free and freezable bound water content increased 21% and 47%, respectively, and non-freezable bound water content decreased 37% when 20% HPMA was added to poly(HEMA). Correlation maps between water content and distribution with previously published properties of elastic modulus (kPa), glass transition temperature (Tg (°C)), void fraction (ϵ), freeze fracture surface roughness (Rq (μm)), the time constant of swelling (τ (min)) and time constant of release of FITC-dextran (40 kDa) (τ (h)) showed that within the freezable water domain, the freezable free water had the larger influence. However, all biotechnical properties of hydrogels were most strongly influenced by the non-freezable bound water content.

Structure–mechanical property relationships in acrylate networks

ABSTRACTThe objective of this work is to investigate the effect of the molecular mobility and resin formulation of UV‐curable acrylate systems on conversion and ultimate mechanical properties. Thin single‐layer films are produced from a series of nine mixtures of bisphenol A ethoxylate diacrylate, having different molecular weights (BisDAn = 2, BisDAn = 4, and a 50/50 mixture), with different amounts of tetraethylene glycol diacrylate (TEGDA) (0, 10, and 30 wt %). Fourier transform infrared analysis, tensile, and dynamic mechanical tests are carried out on UV post‐cured resins, and the results are correlated with the amount of TEGDA. A higher content of TEGDA gives rise to an increase in conversion and glass‐transition temperature. Tests on pure BisDAn = 2 and mixtures of BisDAn = 2 and BisDAn = 4 (BisDAn = 2 + 4) show that with increasing TEGDA content, the crosslink density increases. An increase in molecular weight of the acrylate monomer changes the final mechanical properties of UV‐cured products. A material having a rubber behavior is the result of this change. Next to UV post‐curing, the effect of thermal post‐curing is studied. The results show that thermal treatments affect the mechanical properties mainly if the polymer has a low crosslink density. Formulations highly loaded with TEGDA lead to polymers with high crosslink density, low network mobility, and consequently low mechanical properties if thermally treated. Correlations between, on the one hand, resin formulation and process conditions and, on the other hand, the final mechanical properties of UV‐cured systems are established allowing to optimize the structure–mechanical properties relationship in acrylate networks. © 2019 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48498.

Visible Light-Induced Transformation of Polymer Networks

Light-responsive polymeric networks have shown diverse applications as spatiotemporally tunable materials. Herein, we present a straightforward and facile strategy to fabricate photoexpandable/transformable-polymer networks (PET-PNs) that can undergo a growth mechanism via visible light-induced radical polymerization. Our PET-PN fabrication and its subsequent photogrowth process is based on using a trithiocarbonate chain transfer agent, dibenzyl trithiocarbonate (DBTTC), that can be activated by either photoredox catalysis or direct photolysis (photoiniferter) mechanisms. We first demonstrated the use of a photoredox catalyst (5,10,15,20-tetraphenyl-21H,23H-porphine zinc (ZnTPP) for initiating the reversible addition–fragmentation chain-transfer (RAFT) polymerization of a cross-linkable system consisting of difunctional monomers (i.e., tetra(ethylene glycol) diacrylate (TEGDA)) alongside with a monofunctional monomer (i.e., oligo(ethylene glycol) methyl ether acrylate) (OEGA)) under red LED light (λ max =...

Molecular engineering of poly(HEMA-co-PEGMA)-based hydrogels: Role of minor AEMA and DMAEMA inclusion

Hydrogel membranes of in-dwelling pH-responsive devices are of interest for the development of biomedical sensors that must measure small changes in pH associated with tissue acidosis. Poly(2-hydroxyethyl methacrylate)-based hydrogels possessing minor amounts of the cationogenic N-(2-aminoethyl) methacrylamide (AEMA) (4 mol%) or a tertiary amine moiety, N,N-(2-dimethylamino)ethyl methacrylamide (DMAEMA) (4 mol%) or AEMA-DMAEMA (2 mol% each) were UV cross-linked with 1 mol% tetra(ethylene glycol) diacrylate (TEGDA) and the degree of hydration, free and bound water distribution, glass transition temperature, elastic modulus, membrane resistance and protein adsorption were studied. Correlation analysis reveals that each of these biotechnical properties is strongly anti-correlated with total hydration (−0.92) and that the bound water content dominates this anti-correlation (~−0.83). However, free water shows a direct, though only weak correlation with these properties (~+0.5). Thus, minor changes in the hydrogel composition (~4 mol%) can significantly influence biomaterials properties and may be useful in tailoring hydrogel properties for application in biosensors and engineered tissue scaffolds.

Engineering of a New Bisphosphonate Monomer and Nanoparticles of Narrow Size Distribution for Antibacterial Applications.

In recent years, many bacteria have developed resistance to commonly used antibiotics. It is well-known that calcium is essential for bacterial function and cell wall stability. Bisphosphonates (BPs) have high affinity to calcium ions and are effective calcium chelators. Therefore, BPs could potentially be used as antibacterial agents. This article provides a detailed description regarding the synthesis of a unique BP vinylic monomer MA-Glu-BP (methacrylate glutamate bisphosphonate) and polyMA-Glu-BP nanoparticles (NPs) for antibacterial applications. polyMA-Glu-BP NPs were synthesized by dispersion copolymerization of the MA-Glu-BP monomer with the primary amino monomer N-(3-aminopropyl)methacrylamide hydrochloride (APMA) and the cross-linker monomer tetra ethylene glycol diacrylate, to form cross-linked NPs with a narrow size distribution. The size and size distribution of polyMA-Glu-BP NPs were controlled by changing various polymerization parameters. Near-infrared fluorescent polyMA-Glu-BP NPs were prepared by covalent binding of the dye cyanine7 N-hydroxysuccinimide to the primary amino groups belonging to the APMA monomeric units on the polyMA-Glu-BP NPs. The affinity of the near-infrared fluorescent polyMA-Glu-BP NPs toward calcium was demonstrated in vitro by a coral model. Cytotoxicity, cell uptake, and antibacterial properties of the polyMA-Glu-BP NPs against two common bacterial pathogens representing Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, and two representing Gram-positive bacteria, Listeria innocua and Staphylococcus aureus, were then demonstrated.

Room-Temperature Performance of Poly(Ethylene Ether Carbonate)-Based Solid Polymer Electrolytes for All-Solid-State Lithium Batteries

Amorphous poly(ethylene ether carbonate) (PEEC), which is a copolymer of ethylene oxide and ethylene carbonate, was synthesized by ring-opening polymerization of ethylene carbonate. This route overcame the common issue of low conductivity of poly(ethylene oxide)(PEO)-based solid polymer electrolytes at low temperatures, and thus the solid polymer electrolyte could be successfully employed at the room temperature. Introducing the ethylene carbonate units into PEEC improved the ionic conductivity, electrochemical stability and lithium transference number compared with PEO. A cross-linked solid polymer electrolyte was synthesized by photo cross-linking reaction using PEEC and tetraethyleneglycol diacrylate as a cross-linking agent, in the form of a flexible thin film. The solid-state Li/LiNi0.6Co0.2Mn0.2O2 cell assembled with solid polymer electrolyte based on cross-linked PEEC delivered a high initial discharge capacity of 141.4 mAh g−1 and exhibited good capacity retention at room temperature. These results demonstrate the feasibility of using this solid polymer electrolyte in all-solid-state lithium batteries that can operate at ambient temperatures.

Novel bisphosphonates near infrared fluorescent and non-fluorescent nanoparticles of narrow size distribution for bone targeting

Bisphosphonates (BPs) are a group of organophosphorus compounds which are used in the treatment of various bone related diseases. BPs possess a high affinity to the calcium in bone and thus can be used for bone targeting. Nanoparticles (NPs) are being developed as in-vivo targeted drug delivery systems. In this article, we report the synthesis and characterization of a new bisphosphonate vinylic monomer MA-Glu-BP (methacrylate glutamate bisphosphonate) prepared by interacting methacryloyl chloride with γ-Glu-BP. Non-fluorescent crosslinked bisphosphonate NPs of narrow size distribution were then prepared by dispersion co-polymerization of MA-Glu-BP with a vinylic monomer containing primary amino group, N-(3-aminopropyl) methacrylamide (APMA) and a crosslinker vinylic monomer, tetra ethylene glycol diacrylate (TTEGDA). Near infra-red (NIR) fluorescent crosslinked bisphosphonate NPs were then prepared by covalent conjugation of the NIR dye Cy-7 to the primary amino groups belonging to the APMA monomeric units of the non-fluorescent bisphosphonate NPs. The affinity of the poly(MA-Glu-BP) NPs to calcium was illustrated by interacting the NIR fluorescent poly(MA-Glu-BP) NPs with hydroxyapatite.