Abstract: Disclosed is a self-powered formaldehyde sensing device, comprising: a triboelectric material electrode layer including a first substrate and a first electrode layer formed on the first substrate; a triboelectric material dielectric layer including a second substrate, a second electrode layer formed on the second substrate, a dielectric reacting layer formed on the second electrode layer, and a reaction modification layer formed on the dielectric reacting layer to surface-modify the dielectric reacting layer, the reaction modification layer being a phosphomolybdic acid complex (cPMA) layer, the phosphomolybdic acid complex of the phosphomolybdic acid complex layer being obtained by dissolving 4,4?-bipyridine (BPY) in isopropanol (IPA) and then mixing with phosphomolybdic acid (PMA) solution; an elastic spacer; and an external circuit.

Abstract: A method of preparing biodegradable, water-resistant, moldable paper board or molded paper utensil which includes the steps of: (a) preparing a pulp aqueous slurry at a consistency of about 4%; (b) adding surfactant selected from the group consisting of rosin soap, sodium oleate, sodium stearate, and sodium palmitate to the pulp aqueous slurry; (c) adding between 25-75% weight of a biodegradable and water-resistant agent selected from the group consisting of calcium stearate, cellulose stearate, calcium palmitate and cellulose palmitate to the pulp aqueous slurry to form a slurry mixture; (d) refining the slurry mixture at a consistency of about 4% to a desired drainage; (e) diluting the refined slurry mixture and adding thereto an aggregating agent as alum to form a furnish; (f) forming the furnish to obtain a dry moldable soft paper board; (g) preheating the moldable paper board obtained in step (f) at a temperature from 110.degree. to 170.degree. C.

Abstract: A biodegradable and water-resistant paper product which has the compositions of 8-30% weight of a biodegradable and water-resistant agent selected from the group consisting of calcium stearate, cellulose stearate, calcium palmitate and cellulose palmitate, 92-70% weight of pulp, based on the sum of the dry weight of pulp and water-resistant agent; surfactant selected from the group consisting of rosin soap, sodium oleate, sodium stearate, and sodium palmitate; and aggregating agent as alum.

Abstract: A method of preparing biodegradable water-resistant paper utensils which includes the steps of: (a) preparing a pulp aqueous slurry at a consistency of about 4%; (b) adding surfactant to the slurry; (c) thereafter, adding between 8 and 30 percent weight of a biodegradable and water-resistant agent to the slurry to form a slurry mixture; (d) refining the slurry mixture at a consistency of about 4 percent to a desired drainage; (e) diluting the refined slurry mixture and adding an aggregating agent thereto to form a furnish; and (f) after step (e), forming the furnish to obtain biodegradable, water-resistant paper board or directly a paper utensil. The forming step can be through a hot-press at a temperature of 115.degree. to 170.degree. C.