The present disclosure is directed to a method of chemically stripping a surface. The method comprises applying a sealant to at least a portion of a surface of an object, the surface comprising a coating and one or more ingression points, the sealant filling the one or more ingression points to form a sealed surface. The method further comprises applying a stripping agent to the sealed surface to remove at least a portion of the coating to form a stripped surface.

The present invention relates to n-type conjugated polymers and blends, which is made from aromatic diketone with active methylene or an enolic transformation product thereof, and is obtained directly by polymerization reaction in the presence of an oxidant. The reaction described does not require precious metal catalysis and is insensitive to a reaction atmosphere. A process is simple and inexpensive and suitable for commercial applications. Meanwhile, the modulation of the conductivity of the n-type conjugated polymers can be achieved by ionic modification. The n-type conjugated polymers can be applied to an organic optoelectronic device to achieve an excellent photovoltaic effect.

An organic semiconductor element in which an organic semiconductor layer contains a compound of Formula (1), a compound of Formula (2), and/or a compound of Formula (3) or contains a polymer having a structure of any one of formed by Formulae (8) to (10):

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in which X.sup.1 represents a nitrogen atom or CR.sup.a, and rings A to B each represent a specific nitrogen-containing ring; Y.sup.1 represents an oxygen atom, a sulfur atom, CR.sup.b.sub.2, or NR.sup.c; V.sup.1 represents NR.sup.d, an oxygen atom, a sulfur atom, or a selenium atom; R.sup.a to R.sup.d each represent a hydrogen atom or a substituent; R.sup.1 represents a specific substituent, and p is an integer of 0 to 2; n represents 1 or 2; and * represents a bonding site.

A novel copolymer for use in organic photovoltaics and other related electronic fields and related synthesis pathway. The novel copolymer displays the first example of an H.sub.2DPP co-monomer being directly incorporated into the main chain of a polymer repeat unit to form a co-polymer. An example co-polymer includes H.sub.2DPP-co-ProDOT. The related synthesis pathway displays significant simplicity and eliminates needs for reaction pathways, reagents, conditions, and the like associated with waste, toxicity, and other undesired properties.

A method of chemically stripping a surface is described. The method comprises applying a sealant to at least a portion of a surface of an object, the surface comprising a coating and one or more ingression points, the sealant filling the one or more ingression points to form a sealed surface. The method further comprises applying a stripping agent to the sealed surface to remove at least a portion of the coating to form a stripped surface.

The present invention provides an electrically conductive polymer having excellent electrical conductivity. A polythiophene compound comprising a structural unit of following general formula (A) (wherein L is alkylene or the like; each of M.sup.1 and M.sup.2 is independently an alkyl group, a hydrogen atom, an alkali metal, an alkaline earth metal or an ammonium group; R.sup.1A is a hydrogen atom, an alkyl group, an alkoxy group, an acyl group or a group represented by formula (15); and each of L.sup.1, M.sup.1c and M.sup.2c are respectively the same as L, M.sup.1 and M.sup.2) and having a high absorbance ratio calculated by calculation formula (A.sub.2000/A.sub.407) from absorbance (A.sub.2000) at the wavelength of 2,000 nm and absorbance (A.sub.407) at the wavelength of 407 nm achieves excellent electrical conductivity. Further, an electrical conductive polymer of the present invention is useful as a material for solar cells.

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A compound of formula (I), D.sup.1 and D.sup.2 are electron-donating groups; A.sup.2 and A.sup.3 are electron-accepting groups; B.sup.1 and B.sup.2 are bridging groups; x1 and x2 are 0, 1, 2 or 3; y1 and y2 are at least 1; z1 and z2 are 0, 1, 2 or 3; and A.sup.1 is a group of formula (II) wherein Ar.sup.1 is an aromatic or heteroaromatic group; and Y is O, S, NR.sup.4 or R1-CCR.sup.1 wherein R.sup.1 in each occurrence is independently H or a substituent wherein two substituents R.sup.1 may be linked to form a monocyclic or polycyclic ring and R.sup.4 is H or a substituent. The compound may be used as an electron-accepting material with an electron-donating material in an organic photodetector.

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