Evaluation of adsorption of organic solvents to modified hydrophobic silica adsorbents based on Hansen solubility parameter

Predicting the binding affinity of chemicals to estrogen receptor using Hansen solubility parameters

Receptor-binding tests for the receptors of various substances are widely employed to identify drug candidates and predict the biological effects of chemical substances. Here, the results of chemicals binding to estrogen receptor (ER) reported in a validation study of the Organization for Economic Cooperation and Development TG 455 and the Hansen solubility parameter (HSP) values of the test substances were compared and examined using the Hansen sphere method, thus predicting potential HSPs that correspond to the ER-binding domain of agonists. Based on the results of the validation study and the HSP values of the test chemicals, a Hansen solubility sphere was created, and the ER potential parameter corresponding to the ER was obtained. The binding potential of the test substances to ER was predicted by comparing this potential parameter with the HSP of each test substance. These results indicate that ER binding properties can be predicted with high accuracy using the concept of HSP.

Hansen Solubility Parameters Applied to the Extraction of Phytochemicals

In many analytical chemical procedures, organic solvents are required to favour a better global yield upon the separation, extraction, or isolation of the target phytochemical analyte. The selection of extraction solvents is generally based on the solubility difference between target analytes and the undesired matrix components, as well as the overall extraction procedure cost and safety. Hansen Solubility Parameters are typically used for this purpose. They are based on the product of three coordinated forces (hydrogen bonds, dispersion, and dipolar forces) calculated for any substance to predict the miscibility of a compound in a pure solvent, in a mixture of solvents, or in non-solvent compounds, saving time and costs on method development based on a scientific understanding of chemical composition and intermolecular interactions. This review summarises how Hansen Solubility Parameters have been incorporated into the classical and emerging (or greener) extraction techniques of phytochemicals as an alternative to trial-and-error approaches, avoiding impractical experimental conditions and resulting in, for example, saving resources and avoiding unnecessary solvent wasting.

Balancing Compatibility and Gelability for High-Performance Cholesteric Liquid Crystalline Physical Gels

Liquid crystalline physical gels (LCPGs) have attracted increasing interest because of their mechanical properties and stimulus-response behaviors. However, due to their gelator properties such as thermal stability, gelation capability, and compatibility in liquid crystals, development of LCPGs with high performances still remains a huge challenging task. Herein, four novel gelators ((l)-PH, (d)-PH, (l)-P2H, and (d)-P2H) based on 1,4-benzenedicarboxamide phenylalanine derivatives containing one or two ethylene glycol groups have been designed and synthesized. It is found that the ethylene glycol group plays a significant role in improving the compatibility between the gelator and the liquid crystal. All of the prepared compounds can form stable LCPGs in P0616A. In particular, the storage modulus of LCPG with 9.0 wt % of (l)-PH with one ethylene glycol unit is higher than 10⁶ Pa, which is similar to SmC gels and advantageous over previously reported nematic LCPGs. Furthermore, the prepared gels display a strong Cotton effect with hand-preferred twisted fiber networks and the self-assembled aggregates of (l)-PH can induce P0616A to form a cholesteric fingerprint structure. Thus, these low molecular weight gelators provide a strategy to construct high-performance cholesteric LCPGs for the realization of LC device applications.

Synergistic Effect of Two Plasticizers on Thermal Stability, Transparency, and Migration Resistance of Zinc Arginine Stabilized PVC

The effect of different plasticizers on thermal stability, transparency, and migration resistance of the PVC stabilized with zinc arginine [Zn(Arg)₂] was investigated. The thermal stability, migration resistance, and transparency of PVC with tributyl citrate (TBC) were better than PVC with dioctyl phthalate (DOP) characterized by oven aging method, migration test, and near infrared-visible-ultraviolet spectrophotometer. At the same time, the longer the carbon chain in citric acid esters, the better the thermal stability and transparency of PVC sample. The hydroxyl group in citric acid esters is helpful to improve the thermal stability of PVC samples. However, the elongation at break and T_g value of PVC containing DOP were very close to those of PVC containing TBC. The calculation results of Hansen solubility parameters also illustrated that DOP had better compatibility with PVC than TBC. Therefore, the excellent transparency and thermal stability of TBC plasticized PVC were attributed to the good compatibility between TBC and Zn(Arg)₂, which was verified by the solubility test. Lastly, the mixture of dioctyl terephthalate (DOTP) and TBC was used as plasticizers for Zn(Arg)₂ stabilized PVC. When the ratio of TBC and DOTP was 1:1, the transparency, thermal stability, and migration resistance of Zn(Arg)₂ stabilized PVC samples were better than those of PVC plasticized by DOP or TBC alone. The mechanism was that the compatibility between Zn(Arg)₂ and PVC was greatly improved by the synergetic effect of TBC and DOTP, resulting in the improvement of thermal stability, migration resistance, and transparency of PVC samples.

Adaptation of Hansen solubility parameter in evaluating transparency of composite materials

In the preparation of polymer-based functional materials, it is often difficult to express the desired function using a single substance. Thus, multiple materials are often combined to achieve a desired function using methods such as the addition of a filler or lamination. However, when materials are mixed using a filler, the transparency of the polymer decreases. Therefore, a prediction indicator for transparency is needed. In this study, we focused on using the Hansen solubility parameter (HSP) as a predictor of transparency. The value of δ_d, which is the dispersion force term of the solubility parameter, is considered to be related to the refractive index of the solvent. Silica particles were selected as model particles, and the HSP value was determined. We examined the possibility of evaluating the transparency in a solvent containing silica particles based on the HSP value, and our results indicated that a smaller difference in δ_d between the particles and solvent corresponded with a higher transparency. The HSP value could be used as an index for evaluation of the dispersibility and solubility of the polymer. By using HSP theory in the material design of composite materials, it is thus considered possible to use the same index to simultaneously evaluate the dispersibility evaluation and predict the transparency of the filler.

Measurements of the Hansen solubility parameters of mites and cockroaches to improve pest control applications

Various pests, such as cockroaches and mites, can negatively affect agriculture and human health. Many pesticides have been developed to control these pests. The surfaces of pests are hydrophobic, so an insecticide in an aqueous solution will be repelled by the surface of a pest and therefore will not be effective. Adding a spreading agent (e.g., a surfactant) will improve the ability of a pesticide solution to wet pest surfaces and therefore improve the ability of the active ingredient to permeate and kill pests. Efficiently killing insects requires the insecticidal component to have an affinity for the pest surface. This affinity was assessed here using the Hansen solubility parameter, which is a quantitative measure of the affinity between two substances. We determined HSPs of mites and cockroaches using Hansen solubility sphere method. The HSPs of mites were δ_d = 16.4 (MPa)^1/2, δ_p = 2.6 (MPa)^1/2, and δ_h = 4.7 (MPa)^1/2. The one HSPs of cockroaches were δ_d = 15.5 (MPa)^1/2, δ_p = 20.4 (MPa)^1/2, δ_h = 20.2 (MPa)^1/2, and others were δ_d = 17.6 (MPa)^1/2, δ_p = 2.8 (MPa)^1/2, and δ_h = 3.8 (MPa)^1/2. The HSPs of cockroaches showed two values of hydrophobicity and hydrophilicity. Finally, we proposed new derived guidelines for using Hansen solubility parameters in research into pest control agents.