Fruit Shatian pomelo peel is a common solid biological waste. This article reports the environmentally friendly synthesis of carbon quantum dots from Shatian pomelo peel waste by hydrothermal method. The synthesized carbon quantum dots (named PCA‐CQDs) were characterized by transmission electron microscope (TEM), Fourier transform infrared (FT‐IR) spectroscopy, X‐ray photoelectron spectroscopy (XPS), ultraviolet‐visible spectroscopy (UV‐vis) and excitation‐dependent fluorescence emission spectroscopy. The resultant carbon quantum dots were spherical, and the average particle diameter was measured to be 5 nm. The surface of PCA‐CQDs has been successfully modified with functional oxygen‐containing functional groups such as hydroxyl and carboxyl groups. Therefore, PCA‐CQDs exhibit excellent water solubility and calcium ion chelating properties. Most importantly, PCA‐CQDs were used as a new type of green scale inhibitor for inhibiting the CaSO4 and CaCO3 scale for the first time, and the scale inhibition efficiency can reach more than 95 %. By observing the changes of the scale crystals in the SEM image, it is speculated that the mechanism of PCA‐CQDs inhibiting calcium scale may include chelation, dispersion and lattice distortion.

Polyaspartic acid modified by sulfonic acid group (PASP/ASA) was synthesized and characterized, and then its comprehensive scale inhibition performance was tested in the laboratory simulated environment as an oilfield scale inhibitor. By statically experiment the performance of polyaspartic acid/ aminomethanesulfonic acid in inhibiting CaSO 4 and CaCO 3 scale under different synthesis condition, results present that the maximum scale inhibition efficiency of the prepared PASP/ ASA for CaSO 4 and CaCO 3 scale is 100 % and 83.36 % at the dosage of 2.5 mg L À 1 and 10 mg L À 1 , respectively. However, the average scale inhibition efficiency of PASP/ASA can reach 61.63 % which is higher than 51.21 % of PASP at both dosage of 30 mg L À 1 . PASP/ASA and unmodified PASP exhibit unequal calcium scale inhibition performance because of the introduction of À SO 3 H. The scale crystal morphology analyzed by SEM and X-ray diffraction revealed that the calcium scale crystals were eliminated in the presence of PASP/ASA by chelation, electrostatic dispersion and lattice distortion mechanism.

Dual-response smart window, which can respond to two external stimuli simultaneously or separately, has more solar adjustment modes and a wider range of solar radiation adjustment. In this paper, a double-layer fluorine-tin oxide (FTO) electrical-thermal mold was presented, and poly(Nisopropylacrylamide) (PNIPAm) hydrogel was encapsulated in the mold to form an electric-thermal dual-response smart window. The electrical response refers to the electrothermal conversion characteristics of the double-layer FTO mold used to compensate for the insufficient thermochromic performance of the PNIPAm hydrogel when temperature is between 25°C and 32°C, rather than electrochromic properties. Finally, when the applied voltage reaches 5 V, the dual-response smart window achieves a high solar modulation ability (ΔT sol ) of 26.51 %. In addition, it can be concluded that a 5 V of applied voltage is adequate for the dual-response smart window (25 mm × 25 mm × 2.2 mm) to exhibit excellent ΔT sol and extremely fast response speed by the test of the electrothermal conversion performance, transparency change during the heating process, and UV-Vis-NIR transmittance spectra. Furthermore, the thermal management tests and cyclic stability tests indicate that the smart window has a potential energy saving effect and environmental tolerance. The prepared smart window enables PNIPAm hydrogel to manage solar radiation well in the entire ambient temperature range actively or passively.

Piperidinium-based ionic liquids (ILs) were synthesized under mild conditions by coordinating N-alkyl-N-methylpiperidinium bromide ([Pip 1,x ] Br) with anhydrous AlCl 3. The weak basicity of N-methylpiperidine had little impact on downstream problems from proton impurities and catalyst poisoning. The results of Fourier transform infrared (FT-IR), electrospray ionization mass spectrometry (ESI-MS), and nuclear magnetic resonance (27 Al NMR) confirmed that the active components in [Pip 1,x ]Br-2AlCl 3 (χ = 0.67) were [Al 3 Cl 9 Br] − and [Al 2 Cl 6 Br] −. Besides, the reaction performance of [Pip 1,8 ]Br-2AlCl 3 under different conditions was carried out by single-factor experiment and further confirmed by orthogonal experimental method. Among these reaction conditions, the optimal combination was the reaction temperature of 40 C, ILs/O molar ratio of 0.2:1, px/O molar ratio of 12:1, and the reaction time of 30 min. Furthermore, [Pip 1,8 ]Br-2AlCl 3 had excellent stability and can be recycled 14 times. It was the high-efficiency catalytic activity and prominent recyclability that made continuous industrial production possible.

The combination of nanoparticles and polycarboxylate ether superplasticizers is expected to simultaneously improve the durability and mechanical properties of mortar and concrete. However, the uniform dispersion of nanoparticles in cement materials has always been a difficult challenge. In this paper, nanoparticles are modified with surfactants to provide a research direction for better dispersion of nanoparticles in cementitious materials. Modified allyl ether polycarboxylate superplasticizer with short-branched chains was synthesized from acrylic acid and allyl glycidyl ether. Nano-silica/polycarboxylate ether was obtained by grafting nano-silica onto polycarboxylate ether molecular chains through intermolecular dehydration, thus achieving a homogeneous dispersion of nano-silica in the cementitious material. The results show that nano-silica/polycarboxylate ether has better dispersibility in cement matrix and strong clay resistance, which compensates for the poor dispersion of polycarboxylate ether synthesized from conventional polyethylene glycol graft chains in the presence of clay impurities.