An alternative refined de Sitter conjecture giving rise to a natural combination of the first and second derivatives of the scalar potential was proposed recently by David Andriot and Christoph Roupec (Fortsch. Phys. 67 (2019) no.1‐2, 1800105). In this work, we study the inflation models in a general scalar‐tensor theory with exponential and hyperbolic tangent forms of potential as well as model with quantum corrected potential and examine whether these three models of inflation can satisfy this further refining de Sitter swampland conjecture or not. Regarding our analysis with proper choices of parameters a,b=1−a$a, b=1- a$ and q, we find that these three inflationary models can always satisfy this new refined swampland conjecture. Therefore, all three inflationary models might all be in “landscape” since the “further refining de Sitter swampland conjecture” is satisfied.

In this work, a superhydrophobic surface of poly (vinylidenefluoridene-hexafluoropropylene) (P(VDF-HFP)) fibers was fabricated by means of electrospinning technique. The effects of flow rate on the morphology and hydrophobicity of P(VDF-HFP) nanofibers were investigated by scanning electron microscopy (SEM) and water contact angle (WCA), respectively. The results exhibit a uniform P(VDF-HFP) fiber mat at the lowest flow rate. However, the presence of bead-on-string the fibers was exhibited at higher flow rate. The average fiber diameter of P(VDF-HFP) fibers is increased with increasing flow rates. The WCA values of the P(VDF-HFP) fibers with bead-on-string structure could reach up to 158.60°, indicating as the superhydrophobicity. These as-received porous P(VDF-HFP) fibers with superhydrophobic surface are attractive properties for self-cleaning materials used for further several industrial applications.

We report on the preparation of electroactive β-phase in polyvinylidene fluoride hexafluoropropylene (PVDF-HFP) without any electrical poling treatment. The PVDF-HFP film with various mass fractions (wt%) of magnesium chloride hexahydrate salt (MgCh∼6H2O) was fabricated by a solution casting technique. The morphological, mechanical, structural and dielectric properties were investigated. Results founded that the PVDF-HFP composite films show a large number of micro-pores on the top surface as a sponge-like structure. The Young’s modulus and crystallinity values tend to be linearly decreased with the MgCh2⋗6H2O concentration leading to enhance flexibility. The largest β-phase fraction of 87.2% is found in the composite with 1 wt% MgCh2⋗6H2O filler. The obtained value is 4 times higher than the value of unfilled PVDF-HFP. Moreover, the maximum value of dielectric constant is about 19.2 at 10 Hz for 4 wt% MgCh2⋗6H2O filler. Therefore, the modified composites with the excellent flexibility, dielectric constant and β-phase may be a promising material for applications in the field of piezoelectric energy conversion.

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